TRAFFIC CONTROL MANUAL: 2024 UPDATE

(Last Updated 5/1/2024)

LETTER FROM THE DIRECTOR OF TRANSPORTATION OPERATIONS

This manual is the result of input from the Seattle Department of Transportation's (SDOT) traffic engineers, construction inspectors, safety officers, crew chiefs, contractors, and the traveling public. We have incorporated ideas from public agencies and private companies that work in Seattle's roadways, and those performing day-to-day activities in the street using these guidelines. Our thanks to everyone who helped provide useful revisions and updates to this 2024 update of the manual.

We understand that it is not possible to eliminate all risk from this type of work, but we strive to help build safer work zones both for people working within them and for people traveling around them. Building safer work zones requires care at each step, from developing the plan of work to accurately placing individual traffic control devices. We intend to provide everyone who has to work in the street with the relevant information necessary to carry out their tasks safely. All crews who work in Seattle's public right of way shall set up safe work zones that consistently and clearly convey to all travelers that work is being performed. These work zones guide those travelers in safely and effectively navigating past the work area.

Please use this manual to help make your work zones safer for both people working and people traveling.

Dusty Rasmussen

Director of Transportation Operations

Seattle Department of Transportation

INDEX

PAGES

DIRECTOR'S RULE 3

INTRODUCTION 8

I. GENERAL INFORMATION 9

A. Purpose and Intent 9 B. Responsibility 9

C. Glossary 11

II. GENERAL REQUIREMENTS 13

A. General 13

B. Planning 13

C. Time of Work 13

D. Work Area 14

E. Placing Signs and Equipment 15

F. Short Duration and Mobile Work 16

G. Speed Control 17

H. Parking Control 17

I. Existing Traffic Control Devices 18

J. Maintenance of Traffic Control Devices 18

III. PROCEDURE FOR OBTAINING PERMISSION TO WORK IN CITY STREETS 19

IV. MATERIALS AND PERSONNEL FOR TRAFFIC CONTROL 20

A. Channelizing Devices 20

1. General Application 20

2. Vehicular Barricades 20

a. General Requirements 20

b. Type I and Type II Barricades 21

c. Type III Barricades 21

3. Vertical Panels 22

4. Cones 22

5. Tubular Guideposts 25

6. Drums 25

7. Others 25

B. Channelizing Device Placement 25

C. High-Level Warning Device 26

D. Illumination and Light Device 26

1. Torches and Lanterns 27

2. Flashing Yellow Light 27

3. Steady Burning Electric Lamps 27

4. Floodlights 27

5. Warning Lights 27

6. Advance Warning Arrow Panel 28

E. Pavement Markings 29

F. Flaggers 29

1. Qualifications 29

2. Equipment 29

3. General 30

4. Stations 31

5. Control Procedures and Signals 31

V. TYPES AND METHODS OF SIGNING 32

A. General Requirements 32

B. Regulatory Signs 33

C. Warning Signs 33

D. Guide Signs 33

E. Special Signs 33

VI. PEDESTRIAN ACCESS CONTROL AND PROTECTION 36

VII. BICYCLE ACCESS 41

A. General Requirements 41

B. Work Area Accommodation 41

C. Bicycle Facility Closures, Detours, and Alternate Routes 42

VIII. DETOURS AND STREET CLOSURES 44

A. Permission and Notification 44

B. Detour Requirements 44

C. Requirements Within Streets Closed to through Traffic 45

IX. EMERGENCY WORK 47

X. ENFORCEMENT 48

XI. BARRICADING AND SIGNING ILLUSTRATIONS 49

Channelization and Warning Devices Figure IV-1 24

Regulatory Signs Figure V-1 34

Guide Signs Figure V-2 35

Pedestrian Control Figure VI-1 38 Pedestrian Control Figure VI-2 39

Pedestrian Control Figure VI-3 40

Full Roadway Closure Typical Detour Plan Figure VII-1 46 Symbols and Legends Figure XI-1 51

Lane closure on a Two-Lane Road with Low Traffic Volumes Figure XI-2 52

Work Area on Right Side of Street (Minor Arterial) Figure XI-3 53

Right Lane Closure (4 lane 2 way street) Figure XI-4 54

Left Lane Closure (4 lane 2 way street) Figure XI-5 55

Work Area in Center of Street Figure XI-6 56

Center Lane Closure (one-way street) Figure XI-7 57

Multiple Lane Closure (one-way street) Figure XI-8 58

Traffic Shift Over Centerline Figure XI-9 59

Two-Way Left Turn Lane Closure Figure XI-10 60

Work Area in Center of Intersection Figure XI-11 61

Work Area Beyond Intersection (curb lane) Figure XI-12 62

Work Area Beyond Intersection (center lane) Figure XI-13 63

Work Area Beyond Intersection (center lane-left turn provided) Figure XI-14 64

One Lane Closure (2 lane 2 way street horizontal curve) Figure XI-15 65

Survey Crew (Intersection arterial street) Figure XI-16 66

Bike Lane Closure Figure XI-17

Protected Bike Lane Closure Maintaining Bike Lane Figure XI-18A

Protected Bike Lane Closure Figure XI-18B

INTRODUCTION

This Traffic Control Manual shall be utilized in conjunction with and is intended to supplement the Manual on Uniform Traffic Control Devices (MUTCD), as published by the U.S. Department of Transportation, Washington D.C. The basic principles embodied in the MUTCD have been adapted to urban conditions to provide a user's guide for work within the City of Seattle right of way, under the authority of the Seattle Municipal Code (SMC 11.16.120).

I. GENERAL INFORMATION

A. Purpose and Intent

The purpose of this manual is to set forth the basic principles and standards to be observed by all those who perform work in a public street in the city of Seattle to provide safe and effective work areas and to warn, control, protect, and expedite vehicular, bicycle, and pedestrian traffic.

When proper traffic control techniques are effectively employed, it will be possible to:

1. Minimize or prevent the potential for vehicular, bicycle, and pedestrian collisions.

2. Minimize or prevent injury to workers and the public.

3. Minimize or prevent damage to private and public property.

4. Minimize or prevent the potential of litigation.

5. Maximize mobility and access.

6. Minimize confusion for all travelers.

7. Improve public relations.

In an effort to increase the travelers' understanding and facilitate effective traffic flow, it is desirable to standardize the type and placement of traffic control devices. This manual aims to accomplish this objective by:

1. Using standard techniques for the design and placement of traffic control devices.

2. Including typical examples of proper signing and channelizing techniques.

Although each situation should be dealt with individually, conformity with the general provisions and techniques established herein is necessary. In particular situations not adequately covered by the provisions of this manual, the protection of the traveling public and the worksite will dictate the measures to be taken, consistent with the general principles set forth herein. The obligation to comply with the requirements of this manual and the liability for failing to do so are hereby placed upon the persons, entities, or agencies doing work within or infringing upon the public street right-of-way.

Within this manual, the term City Traffic Engineer is used inclusively to include both the person serving as Seattle's Traffic Engineer and the team of people that have been delegated authority to review, design and modify temporary traffic control within the city.

B. Responsibility

All persons or agencies doing work within or infringing upon the street right of way shall conduct said work to acceptable standards of safety and efficiency and, except where specified in their Contract, shall be responsible for the following:

1. Obtaining all necessary permits and/or permission to perform work in the street right of way from the Seattle Department of Transportation, Street Use Division (see Section III and web link www.seattle.gov/transportation/permits-and-services/permits), or from the Transportation Operation Division, through the Seattle Special Events Office (https://www.seattle.gov/special-events-office) requirements.

2. Obtaining approval for haul route or routes from the City Supervisor of Commercial Vehicle Enforcement (https://www.seattle.gov/transportation/permits-and-services/permits/permit-templates-and-checklists)

3. Supplying, installing, and maintaining all traffic control devices and equipment as outlined in this manual unless specific instructions to the contrary are included in the contract documents.

4. Supplying flaggers and proper equipment when required.

5. Scheduling and expediting the work to minimize inconvenience to the public.

6. Providing adequate safeguards for the worksite and the general public as outlined herein.

7. Calling before digging. Utilities Underground Location Center (UULC) 1-800-424-5555 or 811; www.callbeforeyoudig.org

8. Prominently displaying a large, visible sign at the construction site with (206) 684-7623, or 684-ROAD@seattle.gov.

9. Notify SDOT traffic signals group 10 business days prior to any work that may affect SDOT signal operations. Any temporary signal modifications that are needed to accommodate a Traffic Control Plan (TCP), must be reviewed, approved, and in place before the TCP can be implemented, (206) 391-3714.

10. On each date of work, notify SDOT Transportation Operations Center (TOC) within 30 minutes prior to setting up traffic control devices AND within 30 minutes after removing traffic control devices impacting arterial lanes of travel. Notify via phone at (206) 684-5117 stating location and lane(s)/direction(s) of travel affected.

Glossary

Terminology Definitions

ADA Americans with Disabilities Act (https://www.ada.gov)

Advance Notice Unless otherwise specified, 72 hours minimum notice for an arterial closure and 24 hours for any other right of way closure (Saturdays, Sundays, and Holidays excepted`)

AG Applicant Guide. See also Client Assistance Memo (CAM) 2111

AWS Advanced Warning Sign

Business Day A day other than Saturday, Sunday, or Holiday

CAM Client Assistance Memo. See also AG

Central Business District (CBD) Within this document, that area bounded by Denny Way, Elliott Bay, I-5, and South Royal Brougham Way

Central Retail District Within this document, the area bounded by Virginia Street, Denny WayI-5, Seneca Street, and First Avenue

Contractor Anyone authorized to work in the street right of way

Construction Hub Right of way with specified dense construction, according to the following: http://www.seattle.gov/transportation/hub.htm Commonly referred to as a "Hub"

CP Capital Project

City Traffic Engineer The City Traffic Engineer, including staff authorized to represent him or her

DMS Dynamic Message Sign

Detour Include intent to return to originating path.

Hours of Darkness (Other references Night, Nighttime) The hours from sunset to sunrise

Hours of Daylight (Other references Daylight Hours, Daytime) The hours from sunrise to sunset

Holiday Seattle legal holiday as defined by Seattle Municipal Code 4.20.190(c)

MUTCD Manual of Uniform Traffic Control Devices (U.S. Department of Transportation, Federal Highway Administration)

Officer (UPO) Uniformed Police Officer

PBL Protected Bike Lane

PCMS Portable Changeable Message Sign

Pioneer Square Within this document, that area bounded by Columbia Street, 2nd Avenue, 2nd Avenue South, South King Street, Alaskan Way South

PSM Public Space Management

Public Works Contract A written agreement between the City of Seattle and the Contractor for changes to the Right of Way at the direction of the City by the Contractor, covering the performance by both parties, and enforceable by law

RCW Revised Code Washington

Reroute Intent to provide alternate path next to closure

ROW Right of Way

RS Roadway Structures

SDCI Seattle Department of Construction and Inspections

SIP Street Improvement Permit

SMC Seattle Municipal Code

TCP Traffic Control Plan

TCS Traffic Control Supervisor

UF Urban Forestry

UMP Utility Major Permit

VMS Variable Message Sign

WAC Washington Administrative Code

Warning Device Warning light or vehicle mounted flashing yellow light (see Figure IV1).

Work Area The public right of way within or adjacent to the construction zone

UPO Uniformed Police Officer

Urban Village Areas defined as Urban Center, Hub Urban Village, or Residential Urban Village in the comprehensive plan https://www.seattle.gov/opcd/ongoing-initiatives/seattle-2035-comprehensive-plan.

II. GENERAL REQUIREMENTS

A. General

All traffic control devices shall conform in both design and usage to specifications contained in this manual. Traffic control for in- street work shall follow this manual unless otherwise stipulated in the contract or permit. In the case of emergency work requiring traffic control refer to Section IX.

Additional requirements for public convenience and safety are in the City of Seattle Standard Specifications for Road, Bridge, and Municipal Construction, Sections 1-07.23 and 1-10.

B. Planning

Advanced planning for the work area and affected vicinity is a basic requirement and shall always be undertaken prior to any type of in-street work activities in order to keep traffic obstruction and public inconvenience to a minimum, while providing maximum safety. The Contractor shall not have under construction a greater length or amount of work than can be completed in a continuous and expedient manner.

In order to achieve these goals, the Contractor should visit the job site before starting the job in order to evaluate:

1. Traffic conditions (motorized, bicycle, and pedestrian)

2. Existing traffic controls

3. Traffic lane requirements (11' travel lane is required per direction on arterials and 12' on Major Truck Streets)

4. Physical features

5. Visibility restrictions

6. Problems of access to abutting property

7. Business access and activities

8. Type, number, and location of signs, and channelizing devices, including any specially worded signs or other special devices that may be necessary

9. Adjacency to other jurisdictions. Traffic control for the construction work adjacent to the Seattle city limit shall be coordinated with the appropriate jurisdiction: King County (206) 296-8100 or http://www.kingcounty.gov/depts/transportation/roads/utilities.aspx#permits; WSDOT CTCO office, (206)-440-4471; City of Shoreline, (206) 801-2461; City of Tukwila, (206) 431-2448.

10.A minimum of one week's public notice of impacts to bicycle trails is required, excepting emergency work.

C. Time of Work

No work shall be scheduled on streets and sidewalks during peak traffic hours without written authorization from the City Traffic Engineer. The peak traffic hours for Arterials and Central Business District are from 6:00 a.m. to 9:00 a.m. and from 3:00 p.m. to 7:00 p.m. unless otherwise specified.

There is a Holiday Moratorium for construction. No work shall be scheduled on streets or sidewalks within the Central Retail District and Pioneer Square from Thanksgiving Day through New Year's Day. No work shall be scheduled on streets or sidewalks within the Chinatown-International District (CID) within the three weeks before and after the Lunar New Year (typically in the January-February time frame, exact date varies each year). The Holiday Moratorium maps and additional details can be found in CAM 2107.

The City of Seattle Noise Ordinance allows work as follows:

Weekdays 7:00 a.m. to 10:00 p.m.

Weekends and legal holidays 9:00 a.m. to 10:00 p.m.

Impact tool work weekdays 8:00 a.m. to 5:00 p.m.

Impact tool work weekends 9:00 a.m. to 5:00 p.m.

Questions concerning the Noise Ordinance can be addressed to the Seattle Department of Construction and Inspections at: (206) 615-0808. Additional information can be found at Noise Code - SDCI | seattle.gov.

The contractor may be required to temporarily discontinue work if a possible conflict exists with special events such as parades, sporting events, miscellaneous rallies, and large public meetings or with seasonal conditions such as Christmas. Information may be found at: www.seattle.gov/special-events-office/calendar

D. Work Area

In general, unless the section of street is to be completely closed to vehicular traffic, work shall be accomplished such that as few traffic lanes as possible are affected. Work shall be scheduled and work areas laid out to permit:

1. The maximum number of traffic lanes normally available to be remain open in the direction of the heaviest flow of traffic during the peak hours.

2. Maintenance of two-way traffic at all times except on one-way streets, unless otherwise granted a specific exception, or with a directional closure for a non-arterial approach to an arterial street. Additional width for facilitating traffic flow may be obtained by prohibiting on-street parking adjacent to the work zone.

3. No personal vehicles shall be within the work zone or the buffer zone, or any other area controlled by temporary traffic control. The only vehicles within the work zone shall be vehicles necessary for the work, and care shall be used such that sight distance and access is not blocked, and such vehicles shall be properly marked and equipped with flashing lights for ingress/egress.

4. Traffic should be maintained on a paved surface whenever possible. However, in the event that a graveled or dirt surface must be used as a detour, the Contractor shall maintain a smooth surface and shall control dust. The Contractor shall use flaggers through the off-pavement detour.

5. Spillage from trucks on the sidewalk or driving surface adjacent to the work area shall be cleaned up immediately.

6. Provision for safe and protected pedestrian and bicycle travel routes as outlined in sections VI and VII.

7. The placement of construction equipment shall not create an unnecessary sight or other obstruction to motorized vehicular, bicycle or pedestrian traffic.

8. The Contractor shall be responsible for providing adequate safeguards, safety devices, protective equipment, and any other needed actions to protect the life, health, and safety of the public, workers in the right of way, and property in connection with the performance of the work covered by the contract. The Contractor shall perform any measures or actions the City Traffic Engineer may deem necessary to protect the public, workers in the right of way and property.

Following placement of all necessary traffic control devices, those responsible should drive and walk through the entire work area in the same manner as the public would. Particular attention should be given to the visibility of all signs, including advance warning signs, smoothness of transitions, and placement of any devices which may cause confusion or indecision on the part of an unfamiliar driver, bicycle rider, or pedestrian.

The Contractor shall maintain all work area traffic control devices in a proper condition on an around-the-clock basis, whether or not work is actively being conducted. In addition, the Contractor shall assure that tools and equipment are properly stored and excavation bridging is secure and adequately covering any excavation.

E. Placing Signs and Equipment

Proper placement of signs, channelizing devices, and construction equipment is essential to safe, smooth traffic operation around and/or through the construction area.

The following procedures shall be adhered to:

1. No traffic control equipment, other than parking prohibition signs which must be installed ahead of time, shall be installed except immediately before the work begins. However, if such signs need to be installed as a matter of convenience in advance of the scheduled work, they shall be effectively covered until work begins.

2. Any traffic control equipment not required at any time during the job shall be removed from view during such period.

3. All traffic control devices shall be installed so that they are readily visible to approaching traffic. Traffic control devices should be placed such that they allow the driver to see from one device to the next and are in the same position on successive days unless changes in construction work dictate otherwise.

4. Truck and construction equipment that encroaches onto the traveled roadway for any reason shall be equipped with flashing or rotating yellow/orange warning lights. Unless one or more flaggers are present to control traffic, supplementary traffic control devices shall be placed to warn, slow down, and if necessary, divert traffic around such equipment. Truck and equipment movement during peak hours is prohibited without approval from the City Traffic Engineer.

5. Wherever practical, trucks and equipment should be placed between workers and oncoming traffic to afford added protection for the workers should a driver fail to observe the traffic control devices. The use of such vehicles shall only be considered supplemental to and not a substitute for proper traffic control and warning devices as outlined in this manual.

6. When a steel plate is necessary to cover an excavation, each side of the plate shall have a minimum of 12 inches bearing on the sides of a cut, and shall be anchored by steel pins. Plates shall be bedded on temporary pavement patch material and shimmed to prevent movement, oriented to be perpendicular to traffic, and the bedding shall be tapered on all sides to provide smooth transition for all travelers. Plates shall be textured to provide a non-skid surface in dry and wet conditions acceptable to the City Traffic Engineer. All plates shall be highlighted with paint, and an advance warning sign shall be used to identify the presence of the plate. Plates shall not be left on an undisturbed roadway unless in an approved storage area.

7. When exposed utility manholes or lids are necessary, the Contractor shall ensure minimal exposure to traffic with tapered asphalt mix or equivalent along all sides to minimize hazard, highlighted, with advanced signing warning of the hazard.

8. Signs shall not be placed such that they obstruct a bicycle lane, unless the signs are part of bicycle lane closure.

9. Signs shall be made according to City of Seattle specifications and MUTCD.

10. Work duration is a major factor in determining the number and types of devices used in Traffic Control Plans. The duration of work zone is defined relative to the length of time a work operation occupies a spot location. Per MUTCD, the five categories of work duration and their time at a location shall be:

A. Long-term stationary is work that occupies a location more than 3 days.

B. Intermediate-term stationary is work that occupies a location more than one daylight period up to 3 days, or nighttime work lasting more than 1 hour.

C. Short-term stationary is daytime work that occupies a location for more than 1 hour within a single daylight period.

D. Short duration is work that occupies a location up to 1 hour.

E. Mobile is work that moves intermittently or continuously.

F. Short Duration and Mobile Work

Duration of what constitutes short-duration work may be determined by the MUTCD Section 6G.02 unless it has been approved by the City Traffic Engineer. It is often necessary for certain vehicles to stop for a few minutes within the roadway area in order to perform routine service, such as re-lamping streetlights and access hole inspections. In such cases, specifications for the use of temporary traffic control devices do not need to be followed to the extent specified in this manual, as long as:

1. Such vehicles are equipped with approved flashing or rotating yellow/orange warning lights, or arrow boards.

2. Appropriate warning devices are mounted on the vehicle as high as necessary to be seen by approaching drivers.

3. Supplemental traffic cones (or other suitable channelizing devices) are used to channelize or divert traffic around the vehicle. Such devices shall remain in place until all work has been completed and the vehicle is ready to be moved.

4. If necessary to interrupt traffic flow or if the vehicle obstructs a lane on an arterial street, a flagger for traffic control shall be provided, with three advanced warning signs required for a flagger.

5. A narrative shall be provided as part of the traffic control plan to describe the moving operation, including duration, for all permitted and approved mobile work.

G. Speed Control

In areas where construction operations have changed road conditions, such additional hazards as reduced lane width, adjacent open trenches, temporary roadway, etc., may be considered as evidence of the need for an alteration of the legal (or posted) speed limit. Requests for alteration of the legal speed limits on City streets must be submitted to the City Traffic Engineer.

Normally, proper traffic control plans are designed based on the assumption that drivers will reduce their speeds if they clearly perceive a need to do so. Reduced speed zoning should be avoided as much as practical. However, warning advisory speed plates may be installed under warning signs, based on the conditions of the specific location.

H. Parking Control

Parking restrictions shall be established within construction and maintenance areas where parked vehicles may contribute to hazardous road conditions and restrict traffic flow. In areas where parking pay stations are present, the Contractor shall submit a Temporary No Parking Zone request through the Seattle Services Portal (https://cosaccela.seattle.gov/).

Reservation of curb space within pay station block faces may include the use of "NO PARKING" easel signs (R7-T39), particularly for work performed exclusively outside the normal time period of the metered spaces, such as nighttime or Sunday work, or for requests expected to last longer than 30 days.

If work being performed requires the removal of street signs or pay station devices, or the duration of the request is long-term (greater than 30 days), the Contractor must coordinate with SDOT Transportation Operations Division. Any signs or Pay Station devices that are moved and damaged will be replaced at the cost of the Contractor. SDOT Transportation Operations Division requires no fewer than ten (10) business days in advance for requested removal of pay stations, pay station base plates, or related informational parking signs.

Where no parking pay stations or paid parking elements are present, the Contractor may install "NO PARKING" (R7-T39) easel signs as noted above. Consul Parking (R-444) shall be noted and replaced in kind with a location satisfactory to the affected Consulate (Contact International Programs Director/Office of Intergovernmental Relations, (206) 684-8266). Load zones and disabled parking zones shall be noted and replaced in kind to satisfy users. The necessary substitutions may be made by replacing general purpose parking with temporary signage for the loading or disabled zones.

"NO PARKING" easel signs shall conform in message, dimension and color as indicated in Part V of this Manual. Spacing of such signs shall be appropriate to conditions. "NO PARKING" signs shall have clearly identified the name and phone number of the permit holder restricting the street. "NO PARKING" signs shall have both a start date and time and an end date and time clearly marked on the signs. "NO PARKING" signs shall have a public notice, generated by the Temporary No Parking Zone (Nonpaid Area) application, posted to no fewer than 2 of the required "NO PARKING" signs per full block.

"NO PARKING" (R7-T39) easel signs should be installed at an approximate interval of no more than 30' to 50', with a minimum of four units per each full block.

I. Existing Traffic Control Devices

Street name signs, traffic signs, signals and other traffic control devices are erected by the City to safeguard vehicular, bicycle and pedestrian traffic. A conflict could exist between these devices and construction and repair work.

Since conditions may vary greatly with different projects, no attempt will be made in this manual to designate a specific course of action for each situation. The Contractor shall confer with the City Traffic Engineer prior to beginning work and as necessary throughout the job. Unless previous arrangements have been made, the Contractor shall not revise existing traffic control devices.

J. Maintenance of Traffic Control Devices

In order to function most efficiently and retain their authority, traffic control devices must be well maintained. The City Traffic Engineer may determine adequacy of signing and require removal of any sign or channelizing device where appropriate or necessary.

Signs and channelizing devices shall be kept in proper position, clean, and legible at all times. Damaged, defaced, or dirty signs shall be cleaned, repaired, or replaced. Signals and flashers shall be kept clean. Signs shall not be placed where they obstruct bicycle or pedestrian movements.

Special care shall be taken to see that weeds, shrubbery, parked vehicles, construction materials or equipment, soil, and snow are not allowed to obscure any sign, light, or channelizing device.

III. PROCEDURE FOR OBTAINING PERMISSION

TO WORK IN CITY STREETS

All persons performing work within the street right of way shall obtain approval to partially or completely restrict any Seattle street, sidewalk, or alley. Such restrictions include lane closures, parking restrictions, sidewalk closures, detours, complete street closures, shoulder work, and pedestrian and bicycle rerouting, as well as the placing of building materials or equipment on city streets, sidewalks, or alleys. Persons performing any work which results in such restrictions shall notify the SDOT Transportation Operations Division. If the work to be performed involves the issuance of an SDOT permit, the SDOT Street Use Division will perform this function. (Special Event and Film permits are the exceptions, and these permits are issued by the Seattle Office of Economic Development under approval of the SDOT Transportation Operations Division.) Street Use personnel are responsible for routing their permit to all affected City departments and are responsible for contacting all the other governmental agencies. City staff will input all work into the City's database to populate the City's GIS.

There are several intents of this notification process: to provide for emergency response access; to avoid the conflict of two or more agencies from performing work in the same place at the same time or in conflict of special events; and, to monitor and assist construction and maintenance activities on the street right of way which impacts vehicular, bicycle and pedestrian movement.

Site-specific traffic control plans are required for submittal by the Contractor and approval by the Traffic Engineer as part of the Street Use permit process when:

a) The project will involve an arterial street or street closure within the City of Seattle, and on non-arterial streets within designated Hub areas. Arterial designation is shown on the Seattle Planned Arterial Classifications Map located here: http://www.seattle.gov/transportation/streetclassmaps.htm

b) Moving traffic lanes will be closed during peak hours (6:00 a.m. to 9:00 a.m. and 3:00 p.m. to 7:00 p.m. in the Central Business District; 7:00 a.m. to 9:00 a.m. and 4:00 p.m. to 6:00 p.m. elsewhere)

c) Traffic control cannot be made to match sketches provided within this document

d) Other special circumstances exist as determined by the City Traffic Engineer

The Contractor shall notify King County Metro Transit in advance of any construction that may disrupt transit service according to the following link: https://kingcounty.gov/en/dept/metro/about/contractor-resources/transit-system-impacts

Contact King County Metro Transit at Trolley.Impacts@kingcounty.gov or (206) 477-1150 for trolley line issues, and Construction Coordination staff at Construction.Coordination@kingcounty.gov or (206) 477-1140 for all other government agency transit scheduling issues.

Contact the Seattle Monorail 10 days before working within 14' (in any direction) of the monorail guideway or columns. Contact information can be found here: www.seattlemonorail.com/working-near-the-monorail/. For emergency situations where 10 days advance notice cannot be given, call the Monorail Operations Supervisor phone (206) 396-5009.

The approval of a traffic control plan is limited to the specific work submitted. If another Contractor wishes to use the plan, or subsequent work develops at a later time, the plan shall be resubmitted.

IV. MATERIALS AND PERSONNEL FOR TRAFFIC CONTROL

A. Channelizing Devices

1. General Application

The primary function of channelizing devices is to warn and alert drivers, bicyclists, and pedestrians of worksites in or near the traveled way, and to guide and direct them safely past it. The effectiveness of the device is determined by position and visibility.

Channelizing devices are used:

a) To protect the work site.

b) To provide for pedestrian movement around the work site.

c) To channel and divert traffic in advance of the work site.

d) To define the traveled way through and around the work site.

e) To define a change in the position of the existing lanes around the work site.

f) To define curves and the edges of the roadway on detour routes.

g) To separate opposing lanes of traffic.

Channelizing devices shall conform to the following requirements:

a) They shall be constructed in a manner and material that will withstand routine wear and tear while in use as part of a Traffic Control Zone.

b) They shall comply with the requirements of the National Cooperative Highway Research Program Report 350 and MASH AASHTO Guidance | FHWA (dot.gov).

c) All channelizing devices used at night shall be reflectorized unless otherwise specified herein.

d) The predominant color for the devices shall be orange.

2. Vehicular Barricades

a. General Requirements

Barricades are channelizing devices used primarily for enclosing a work area, for road closures and detours, for pedestrian control, for marking obstructions and where warranted, for guiding traffic around the work area. All barricades shall be constructed of durable materials in conformance with the dimensions and standards indicated on Table IV-1 and Figure IV-1:

Markings for all barricade rails shall consist of weatherproof reflectorized sheeting with alternate orange and white stripes.

Both orange and white stripes shall be reflectorized. The presence of warning lights mounted on the barricade shall not lessen this requirement, nor shall paint containing glass beads be used to provide the reflective surfaces. The 6" wide reflectorized stripes shall slope downward at an angle of 45 degrees in the direction traffic is to pass. Where barricades extend entirely across a roadway, the stripes should slope downward in the direction toward which traffic should move. Where both right and left turns are provided, the chevron striping shall slope downward in both directions from the center of the barricade. Barricades shall be posted in such a manner so as to clearly indicate the extent of the obstruction of excavation.

Barricades shall never be placed in an active lane of traffic, including bicycle lanes and shoulders used by bicycles, without advance warning including an arrow sign or arrow board, and appropriate delineation and advance warning signing.

If it is necessary to ballast barricades to maintain them in an upright position due to high winds or passing vehicles, sandbags or other non-rigid material should be used.

When barricades are used during the hours of darkness an operable flashing or steady burning light shall be attached to each barricade.

When used for the purpose of road blockage, barricades should be no further apart than 5 feet to prevent vehicles from driving between them. If it is necessary to provide space for special traffic (i.e., local residents, construction vehicles, buses, etc.), signs reading "EXCEPT TRUCKS," "EXCEPT BUSES," "CLOSED TO THRU TRAFFIC," "LOCAL ACCESS ONLY" or other appropriate message shall be displayed to approaching traffic.

Generally, barricades shall be one of three types: Type I, Type II, or Type III. Characteristics and dimensions for these three types are shown on Table IV-1 and illustrated in Figure IV-1. The Contractor's name or identifying number shall appear on the barricade but not on the uppermost reflective panel. While each situation should be evaluated for the most desirable application, generally the different type barricades should be used as follows:

b. Type I and II Barricades (Figure IV-1)

Type I and Type II barricades are generally considered portable barricades. Their primary use is to outline work areas, excavations, spoil piles, and similar obstacles. A Type I or Type II barricade may be used to protect pedestrians from vehicular movements. Type II barricades may be used for street closures only in emergency situations or for very short durations.

c. Type III Barricade (Figure IV-1)

Because of their high visibility and more semi-permanent nature, Type III barricades shall be used whenever it is necessary to partially or fully close any street for an extended period of time, to protect work areas of prolonged construction projects. Barricades must be crash test approved per the most up to date NCHRP 350 or MASH requirements.

Street closures require a minimum of 270 square inches of retro reflectivity facing drivers per barricade.

3. Vertical Panels (Figure IV-1)

A vertical panel is a channelizing device that aids the driver in determining the location and alignment of the traffic lane. Vertical panels may be used to divide the opposing streams of traffic at night, to divert a traffic lane, or to outline the edge of a hazard along the roadway. When a vertical panel is used to divide opposing flows of traffic, both sides of the barricade shall be striped with proper angle slashes.

4. Cones (Figure IV-1)

Cones may be used to channel and divert traffic in advance of work sites and to define the travel way through the work site. Traffic cones may be used during daylight hours, but alone are not sufficient for nighttime use.

Minimum height for traffic cones shall be 18". On roadways with a speed limit of 25mph or higher, cones with a minimum height of 28" shall be used. Because they are easily knocked over by wind or by passing vehicles, cones may be doubled up to increase their weight and should be checked frequently (minimum of once per shift and once after shift) to ensure that they are in the intended position.

For nighttime use, cones shall be at least 28" and retroreflectorized. Retroreflectorization shall be provided by a minimum 6" white band placed at a maximum of 3" from the top and an additional 4" wide white band located approximately 2" below the 6" band.

Cones shall be predominately orange.

5. Cane Detection

Waterfilled barricades or other cane detectable devices may be used to divert pedestrians around a work zone, and shall be used in arterial or high volume vehicular traffic areas. Devices used to channelize pedestrians shall be cane detectable.

Where barricades are used to channelize pedestrians, there shall be continuous detectable bottom and top rails with no gaps between individual barricades to be detectable to users of long canes. The bottom of the bottom rail shall be no higher than 6" above the ground surface. The top of the top rail shall be no lower than 36" above the ground surface.

If drums, cones, or tubular markers are used to channelize pedestrians, they shall be located such that there are no gaps between the bases of the devices, in order to create a continuous bottom, and the height of each individual drum, cone, or tubular marker shall be no less than 36" to be detectable to users of long canes.

6. Tubular Guideposts (Figure IV-1)

Tubular guideposts cover a wide range of devices, all of which can be effectively used to channelize and divert traffic in the same application as cones. Generally, these devices consist of a round or rectangular plastic tube fastened to a base plate of similar material as shown in Figure IV 1. Reflectorization shall be provided by a minimum of two 3" white bands, placed a maximum of 2" from the top with a maximum of 6" between the bands.

7. Drums (Figure IV 1)

Because of their universal nature, drums can usually be used in the same application as other channelization devices including Type I and Type II barricades (i.e., to define work areas, divert traffic, protect workers, and support signs.) The predominant color on drums shall be orange with at least two horizontal, circumferential white and orange stripes 4" to 6" wide. Drums shall be retroreflectorized and shall never be placed in the roadway, including bicycle lanes and shoulders commonly used by bicyclists, without advance warning signs and/or proper delineation. A flashing warning light shall be added when drums are used singly or at night. Steady lit warning lights or arrow warning signs should be added when they are used for ballast when it is necessary to prevent overturning such as when signs are attached. Use of double collars is required in high-speed applications or whenever stability is a concern.

8. Others

Various other approved channelizing devices may be used such as temporary flex beam guardrails and median barriers. Glue-down delineators may be used with approval for locations that require longer-term or low-maintenance application. Temporary Object Markers are used for tracking path through intersections. Caution tape is not recommended except in emergencies.

B. Channelizing Device Placement

For maximum effectiveness, the following rules shall be observed in placing channelizing devices for the purpose of channeling and/or diverting traffic:

1. Place channelizing devices in continuous rows. For each row the devices should be of the same type.

2. The channelizing devices shall be placed and anchored if necessary to prevent being knocked out of position by passing traffic. Where used to define traffic lanes, sufficient lane width should be provided so that trucks and buses will not strike them. Additional lane width and clearance may be required on curves and at intersections, where the "tracking effect" of wide swinging semi trucks tend to knock over or crush improperly placed devices.

3. The channelizing devices shall be placed with their broadsides, lamps, and reflectors facing traffic.

4. Where used to close a traffic lane and to transition oncoming traffic, the minimum taper length and spacing between the devices shall be as indicated in Table X 1. The minimum desirable length indicated in Table X 1 applies to roadway conditions of relatively flat grades and straight alignment. Adjustments may be necessary to provide adequate sight distance on the approach to the channelization. Similarly, the proximity of interchange ramps, crossroads, etc., to the work site may dictate the need for adjustments. In general, improved traffic flow will result when the adjustments consist of increasing the length of the taper rather than reducing the length below the minimum as stated in Table X 1.

C. Illumination and Lighting Devices

Often, persons working in the right of way only see the job site during the daytime. It is also necessary to protect the public and the job site during the hours of darkness.

During the day obstructions may be clearly visible, and channelizing devices may be merely of secondary importance. However, at night the work area may not be visible, and the public is reliant upon properly illuminated warning devices. Barricades, signs, and other traffic control devices that do not have lighting or retroreflective features may not be effective after dark and may pose secondary concerns.

All traffic control devices, except parking signs and signs intended to inform pedestrians, used during the hours of darkness shall be properly reflectorized as described elsewhere herein. In addition to these requirements, other devices may be applied during the hours of darkness.

1. Flashing Yellow Warning Light (vehicle mounted)

Flashing or rotating yellow/orange warning lights for mounting on vehicles shall cast a yellow/orange light radially through 360 degrees. Such lights should be approximately 5" high and 5" in diameter and shall be rated at a minimum 750-candle power. Strobe type LED flashers may be a lesser dimension.

When mounted on equipment they shall be positioned such that maximum visibility from all sides is achieved. Lights shall be such that a minimum sustained flash rate of 60 flashes per minute is produced. Light pulsations may be achieved by either rotation of the light source or a strobe-type unit.

2. Steady Burning Electric Lamps

As used herein, steady burning electric lamps shall mean a series of low-wattage yellow electric lamps. Where lights are needed to delineate the traveled way through and around obstructions or to separate opposing traffic in a construction or maintenance area, the delineation should be accomplished by use of steady burning lamps.

3. Floodlights

Electric lights can be used for floodlighting unexpected conditions, signs, channelizing devices, and flagger stations. Lights used for illuminating signs or channelizing devices shall be sufficient in size and number to provide effective illumination and legibility under normal atmospheric conditions. Precautions shall be taken when placing lights to ensure the prevention of glare.

4. Warning Lights

As used in this manual, barricade warning lights are portable, lens-directed, enclosed lights. The color of the light emitted shall be yellow and may operate either in the flash or steady burn mode. These devices shall meet the current MUTCD guidance. A warning light shall be on the traffic-facing side of a permitted dumpster or storage container on the traffic side during nighttime or limited light conditions.

5. Reflectors

Reflectors shall be used on the corners of dumpsters or storage containers permitted in a non- travel lane area of the roadway during nighttime or limited light conditions. Red reflectors shall be placed on the side of the dumpster or storage container facing traffic.

Type A Low Intensity Flashing Warning Lights are most commonly mounted on advance warning signs, Type II barricades, vehicle panels, or on independent supports, and are generally used to warn road users of a hazardous situation.

Type B High Intensity Flashing Warning Lights are normally mounted on advance warning signs or high-level warning devices. Hazardous site conditions within the construction area may require that the lights be mounted on Type I and Type II barricades, signs, or other supports. As these lights are effective in daylight as well as dark, they are designed to operate 24 hours per day.

Type C Steady Burn Lights are intended to be used to delineate the edge of the traveled way on lane changes, on lane closures and on other similar conditions. When mounted on vertical panels they may be used to separate opposing flows of traffic.

Overhead Clearance

Overhead and gantry cranes that are not permanently installed must follow the applicable requirements in chapter 296-155 WAC Part L.

6. Advance Warning Arrow Panel

Advance warning arrow panels are sign panels with a matrix of lights capable of either flashing or sequential displays. Advance warning arrow panels shall be used on roadways with speed limits of 35 mph or greater. Advance warning arrow panels are intended to supplement other traffic control devices. Arrow panels will not solve difficult traffic problems by themselves, but they can be very effective when properly used to reinforce signs, barricades, cones, and other traffic control devices. Necessary signs, barricades, or other traffic control devices shall be used in conjunction with the advance warning arrow panel, and caution shall be used so as to not block sight distance for entering or turning traffic.

Arrow panels provide additional advance warning and directional information where traffic must be shifted laterally along the roadway. Arrow panels are effective in encouraging drivers to leave the closed lane sooner. They assist in diverting and controlling traffic around construction or maintenance activities being conducted on or adjacent to the traveled way and give traffic positive guidance about a roadway route diversion that they might not otherwise expect.

Arrow panels are generally used for day or night lane closures, roadway diversions, and slow-moving maintenance and construction activities on the traveled way. They are particularly effective in high speed and high-density traffic conditions. At night, they are effective where other traffic control devices cannot provide adequate advance warning of a roadway diversion. During daylight, arrow panels are effective under high slow-moving traffic conditions that might block the traveler's advanced view of construction or maintenance activities ahead.

E. Pavement Markings

The City Traffic Engineer shall review with the Contractor situations that merit either the removal of existing pavement markings or the application of temporary markings. Where existing pavement markings conflict with the temporary markings, consideration shall be given to their removal depending upon the extent of conflict and the relative potential impacts. The City Traffic Engineer shall make the final determination. All pavement markings shall be removed and/or applied by the Contractor as approved or directed by the City Traffic Engineer. Temporary pavement marking shall match the standards and specifications as the permanent pavement marking. The pavement marking shall match in kind with the specifications. Upon completion of construction, all pavement markings and channelization removed or damaged shall be replaced by the Contractor.

F. Flaggers

1. Qualifications

Since flaggers are responsible for human safety and typically make the greatest number of public contacts of all construction personnel, it is important that qualified personnel be selected. All flaggers must possess a card certifying that they have completed the flagger's course as approved by the State of Washington Department of Labor and Industries. In addition, all setups involving flaggers must adhere to the Washington State Safety Laws (WAC Ch. 155-305 part E) and/or Ch. VI of the MUTCD.

2. Equipment

While flagging during daylight hours, a flagger must at least wear as an outer garment:

A high-visibility safety garment designed according to Class 2 specifications in the ANSI/ISEA 107-2004, American National Standard for High-Visibility Safety Apparel, consisting of at least 775 square inches of background material that are fluorescent yellow-green, fluorescent orange-red or fluorescent red in color; and 201 square inches of retroreflective material that encircles the torso and is placed to provide 360 degrees visibility around the flagger.

A high-visibility hard hat that is white, yellow, yellow-green, orange or red in color (WAC 296-155-305).

Jackets or vests shall be properly worn and buttoned or zipped for maximum 360-degree visibility and effectiveness.

The flagger shall also be equipped with a standard STOP SLOW hand paddle or pole type paddle. Sign paddles shall be at least 18" wide with 6" letters. A light semi-rigid handle should be provided. This combination sign may be fabricated from sheet metal or other light semi rigid material. The background of the STOP face shall be red with white letters and border. The background of the SLOW shall be orange with black letters and border. When used at night, the stop/slow paddle shall be retroreflective.

For nighttime operations, jackets and vests shall be retroreflectorized and meet the most current version of the Performance Class 2 or 3 requirements of the ANSI/SEA 107. In addition to the retroreflectorized clothing and STOP/SLOW paddle, the nighttime flagger should also be equipped with a flashlight or other lighted signal device. The flashlight or signal device shall be equipped such that a red color is visible and shall be used to accentuate hand signals, which may otherwise not be visible. Care must be taken that the light is not of such intensity as to produce glare to oncoming traffic or obscure the sign message.

3. General

Sometimes traffic control equipment alone is inadequate and flaggers should be used, such as:

a. Where workers or equipment are intermittently blocking a traffic lane

b. Where equipment is backing

c. Where only one lane is available for two directions of travel. When the one lane section is visible from one end to the other end, traffic shall be controlled by means of a flagger at each end of the section. One of the two should be designated as the chief flagger for purposes of coordinating movement. They should be able to communicate with each other verbally or by means of signals. These signals should not be mistaken for flagging signals. When the end of a one-lane section is not visible from the other end, the flagger may maintain contact by means of radio or field phones, or additional flaggers may be stationed at intermediate points.

d. Where traffic control equipment is being placed or removed in the roadway.

e. In emergency situations until proper traffic control equipment can be obtained and properly installed.

f. When existing traffic signals are to be countermanded, in which case only a Uniformed Police Officer shall be the flagger.

g. To assist in the control of all modes of transportation, including vehicles, bicycles, and pedestrian traffic.

Other general rules pertaining to flaggers include:

a. At no time shall a flagging station be left without a flagger.

b. To keep traffic moving, travelers who stop with questions should be advised as briefly as reasonably possible.

c. The flagger should not initiate conversations with travelers and should avoid arguments.

4. Stations

Flagger stations shall conform to the following criteria whenever possible (see illustration in Chapter VIII):

a. They should be stationed far enough in advance of the work area to properly slow or stop traffic before it enters the work area.

b. Flaggers should stand adjacent to the travelers being controlled or in the closed lane prior to stopping travelers. A flagger shall only stand in the lane being used by moving travelers after the travelers have stopped.

c. Flaggers should stand apart from the other crew members and should not mingle with others while on duty. Flaggers should be aware of their position relative to construction equipment such that they do not blend in with their background.

d. Flagger stations shall be provided with advance warning signs as indicated in the illustrations in Chapter XI especially in the case where one lane is being used for two directions of travel.

e. During the hours of darkness, flagger stations shall be illuminated.

5. Control Procedures and Signals

Flagger signals to travelers should use devices and methods as described in the MUTCD.

It is required that a flagger station shall be at least 50 feet from any intersection if the signals are not disabled or turned to flashing red. Also, flaggers should alert drivers that motorists must still obey active signals. At no time shall traffic be flagged with an active signal in full Green-Yellow-Red operation. (WAC 468-95-3015).

A UPO is required for countermanding a traffic signal.

V. TYPES AND METHODS OF SIGNING

A. General Requirements

Signs shall meet the following standards:

1. They shall conform in size, shape, color, material, and message with those included in this manual or in the MUTCD.

2. The use of stripes (other than the standard border) or other geometric patterns or contrasting colors on or around the sign shall not be permitted; however, standard fluorescent red/orange flags or yellow flashing lights may be used for added emphasis so long as they do not interfere with the sign message.

3. All signs used shall be properly retroreflectorized except for parking signs and signs intended to inform pedestrians. Retroreflectorization of the sign face shall be accomplished using an approved weatherproof, retroreflective sheeting, high intensity prismatic or as approved for night conditions. Paint impregnated with glass beads shall not be used. Where retroreflectorization is rendered ineffective due to extraneous light sources, the sign shall be illuminated either externally or internally. Where external illumination is used, the source shall be properly shielded to reduce glare. Street or highway lighting shall not be considered adequate for illuminating signs. All reflectorized or illuminated signs should be checked by the Contractor during the hours of darkness to ensure that they are functioning properly.

4. Signs shall be constructed from material which will not deteriorate abnormally under normal weather conditions. Sign blanks should be weatherproof plywood or noncorrosive metal. Rollup signs fabricated from vinyl coated nylon or vinyl coated nylon mesh may also be used. If such signs are not retroreflectorized, they shall not be used at night.

Sign placement and usage shall generally conform to illustrations in Chapter XI of this manual unless special circumstances indicate that some other placement is more advantageous to convey the proper message to the traveling public. The designation given below each sign in Figures V 1 and V 2 is the City of Seattle's codesign code and the MUTCD sign code may be different. In addition, the following shall be adhered to:

a. Signs shall be placed in a position so that they will convey their message most effectively without restricting lateral clearances or sight distance.

b. Normally, signs shall be mounted on the right-hand side of the roadway; however, gated installations (one sign on the left side and one on the right) should be used where increased emphasis is necessary, and on one-way streets. Signs may also be placed in a closed lane if such placement is most advantageous and does not present a hazard. Signs shall not be placed where they obstruct bicycle or pedestrian movement.

c. All permanent curb or shoulder mounted construction signs shall be mounted to maintain a standard minimum horizontal clearance of 2' from the curb or pavement edge and a standard minimum vertical clearance of 7' above the ground. Where equipment, pedestrians, vehicles, or other obstructions obscure the signs or when they are used on high-volume, high-speed facilities, higher mounting heights should be used.

d. Signs may be pedestal or post-mounted or may be mounted on portable sign supports, high-level warning devices, or utility poles (with authorization of the utility in question). All signs and mounting apparatus shall be securely fastened or weighted so that they are not moved or blown over by wind or passing traffic.

e. Spacing of advance warning signs shall be as indicated in the tables included with the illustrations in Chapter XI unless special circumstances indicate that different spacing would be more advantageous. Advance warning signs used for flagging operations must be set up and spaced in accordance with WAC 296-155-305.

B. Regulatory Signs

Since Regulatory Signs impose legal obligations and/or restrictions, all shall comply with specifications contained in the MUTCD and their use must be approved by the City Traffic Engineer prior to installation. Several of the more commonly used regulatory signs are included here for reference as to size and designation. No existing regulatory sign shall be changed without permission of the City Traffic Engineer.

C. Warning Signs

Warning Signs as used herein are generally diamond shaped with black symbols or letters on an orange background. Warning signs are used to alert motorists of abnormal conditions on the roadway resulting from construction or maintenance work. The more commonly used construction warning signs and sizes are illustrated in this section. Warning signs not included here and deemed necessary for a specific project shall comply with those included in the MUTCD.

Reference should be made to Table XI 1 and the illustrations in Chapter XI of this Manual for use, spacing, position, etc., of the warning signs.

D. Guide Signs

The function of this class of sign on a construction project is to indicate to drivers the path they must follow through a detour in order to bypass the construction and continue to their intended destination. The most common types are Detour and Detour Arrow signs. The street name may be added to help define the detour route.

E. Special Signs

As needed for specific projects, signs with special or nonstandard messages may be required to properly convey information to motorists, bicyclists, or pedestrians. These signs should follow as closely as possible principles and standards set forth in this manual and the MUTCD and shall be approved by the City Traffic Engineer before installation.

VI. PEDESTRIAN ACCESS CONTROL AND PROTECTION

Pedestrian mobility in and around work zones shall follow SDOT Director's Rule 10-2015 http://www.seattle.gov/transportation/drules.htm.

Protective barricades, fencing, and bridges, together with warning and guidance devices and signs, shall be utilized so that the passageway for pedestrians is ADA-accessible, safe, and well-defined. Pedestrian walkways across excavations shall be provided with suitable handrails. Foot bridges shall be safe, strong, free of bounce and sway, and free of cracks, holes, and irregularities that could cause tripping. Wheelchair-accessible ramps shall be provided at the entrances and exits of all raised footbridges.

Adequate illumination shall be provided during hours of darkness. All walkways shall be maintained at least 4' wide, and if located on a sidewalk adjacent to the curb face, 18" buffer between the sidewalk and the travel lane, with 7' wide pullouts every 85' except in areas of unusually heavy pedestrian traffic such as business districts, where the minimum width should be 8'. A pullout is defined as an area where one wheelchair can pass another wheelchair in the opposite direction. Pedestrian access to signed school crossings shall be maintained at all times.

Where existing walkways are closed by construction, an ADA-accessible alternate walkway shall be provided, preferably within the planting strip area or Amenity zones. Where it is necessary to divert pedestrians into the roadway, barricading or channelizing devices shall be provided to separate the pedestrian walkway from the adjacent traffic lane. Temporary curb ramps with compliant 4'x4' landings shall be provided to maintain wheelchair accessibility. At no time shall pedestrians be diverted into a portion of the street used concurrently by moving vehicular traffic.

Temporary pedestrian curb ramps must be constructed as shown in the traffic control plans or be pre-manufactured devices meeting the requirements of the ADA Accessibility Standards, see Chapter 4: Ramps and Curb Ramps at www.access-board.gov.

1. Curb ramps are required to be at least 36 inches wide with a firm, stable, and non-slip surface.

2. Edge protection with a two-inch minimum height is required for ramps with a rise greater than six inches or a side apron slope greater than 33 percent.

3. Edge protection is required on ramps with a vertical elevation over six inches and show a contrasting color where the walkway changes direction (turns).

4. Curb ramps and landings are required to have a two-percent maximum cross slope.

5. Provide a clear space of at least 48 inches by 48 inches above and below the curb ramp.

6. Mark the curb ramp walkway edge with a contrasting color two to four inches wide unless color-contrasting edging is used, as required by item 3 above.

7. Water flow in the gutter should have minimum restriction.

8. Limit lateral joints or gaps between surfaces to be less than half an inch wide.

9. Changes between surface heights should not exceed half an inch. Lateral edges should be vertical up to 0.25 inches high and beveled at 1:2 when between 0.25 and 0.5 inches high.

At locations where adjacent alternate walkways cannot be provided, appropriate signs shall be posted at the limits of construction and in advance of the closure at the nearest crosswalk or intersection to divert pedestrians across the street. A flagger may be required on arterials to assist pedestrians across the street at non-signalized intersections.

To prevent visually impaired people from inadvertently entering a closed area, physical barricades shall be installed to prevent passage. Devices which channelize pedestrians to a defined path shall have a rail within 2'' of the path surface for cane detection and shall be spaced closely enough to maintain cane detection. All pedestrian walkways shall be ADA-accessible at all times. Pedestrian access shall be maintained to all properties adjacent to the construction site.

If a structure such as a Conex container is used for a pedestrian walkway, that structure shall be located a minimum of 18" behind the face of the curb, or traffic control devices shall be used to maintain an 18" clearance of traffic from the structure. The structure shall have a washable floor, with non-skid even transition from sidewalk to structure, illumination sufficient to replace ambient lighting, and windows at sufficient intervals to allow visual access by traffic. The structure shall be illuminated on the traffic side as described above.

Where required by special provisions, fixed pedestrian walkways (of fence and canopy type as illustrated in Figure VI 3) located within a travel lane or parking lane shall be considered and shall include the following:

1. The pedestrian approach ends of the barricade shall have a fixed handrail extending from curb to outermost side of the pedestrian walkway. The area from the handrail to approximately the bumper rail shall be covered and marked with standard 45-degree angle orange and white reflectorized markings sloping downward on the side on which traffic must pass. The area of this panel shall have a minimum of 4' x 2' retroreflective sheeting.

2. When a covered walkway is needed, a high-level warning board with a minimum height of 2' and width equal to that of the walkway shall be mounted above the covered pedestrian walkways on the traffic approach. The warning board shall be striped with the standard 45-degree angle orange and white markings sloping downward on the side on which traffic must pass.

3. Yellow warning lights shall be mounted on 20' centers along the traffic side of the barricade. They shall be installed approximately 8' above the roadway surface.

4. A continuous 2" x 12" bumper guardrail should be mounted on the street side of the structure at a height of 10" from the pavement to the bottom of the rail.

5. The street side of a walkway shall be 3' to 6" high from the bottom of the walkway, plus or minus 6", excepting structural members, for security concerns.

6. Relocating a pedestrian crosswalk further than 10' from pedestrian signal indications requires use of a UPO or installation of a temporary pedestrian signal head.

7. School routes require special attention. For more information, see: https://www.seattle.gov/transportation/projects-and-programs/safety-first/safe-routes-to-school/school-walking-maps

8. Pedestrians shall have sufficient clearance such that they do not walk into inlet grates or normal gutter flow.

9. Pedestrian detours shall not exceed more than 2 blocks or 750' in total length to return to the intended equivalent location.

10. Where pedestrian access cannot be maintained adjacent to the worksite for reasons of pedestrian safety or other considerations as allowed in the Seattle Municipal Code, pedestrians will be directed to the closest open sidewalk of same designation.

11. In the CBD and Urban Village Areas, it is required to border temporary walkway with water-filled barriers that extend the sidewalk around the closed work zone.

BICYCLE ACCESS

A. General Requirements

Bicyclists can legally use street or sidewalk and need to be considered under both conditions. When work encroaches upon a bike lane, shared use path/trail, shared lane, or a road or sidewalk commonly used by bicyclists as identified on SDOT's "Bike Web Map" https://www.seattle.gov/transportation/projects-and-programs/programs/bike-program/bike-web-map, an accessible, safe and clearly defined route shall be provided and maximum effort made to provide a convenient bicycle facility separate from active work areas. The Contractor shall not force a cyclist into conditions such as grating, debris, potholes, Streetcar tracks, gravel, unacceptable pavement conditions, or an abrupt stop within moving traffic as part of traffic control. Bicycle lanes and other identified bicycle routes shall be kept free of obstructions. Long-term closures of bicycle facilities require consideration of an alternate bicycle facility, either restriping with or without traffic control devices or detouring.

Closing a bike lane requires the same signage and traffic control as a motor vehicle use lane. Proposals to close a bike lane shall demonstrate that impacts cannot be reasonably avoided through alternative construction methods, that the facility cannot be reasonably relocated through reassignment of vehicle lanes or other existing facilities, that the duration and extent of impacts have been minimized, and that an adequate detour has been provided. The Contractor shall seek to safely accommodate bicycles through the work area and avoid installing "Bicyclists dismount" signs at the closure of a bicycle lane to the extent possible but shall use advance signage that the bicycle lane is closed at a place where the cyclist can modify their route as necessary.

Regional trails, such as the Burke-Gilman Trail, need to have signing and traffic control equipment that meet the needs of both pedestrians and bicyclists. A minimum width of 10' should be maintained on these trails. If this width cannot be provided, flagging and/or an approved detour route shall be required.

B. Work Area Accommodation

The Contractor shall accommodate bicyclists in work areas as follows:

1. The Contractor shall provide safe and protected bicycle access into, through, and out of the work area, including proper channelization and signage. The method for providing safe accommodations for cyclists should be prioritized as follows:

A. Provide a temporary bike lane on the same roadway past the work zone by shifting and narrowing the adjacent traffic lanes.

B. Provide a temporary bike lane in an existing traffic lane on multilane streets.

C. Merging cyclists and adjacent traffic into a shared travel lane (except on streets with a posted speed of 30 mph or greater).

D. Directing cyclists onto a shared path with pedestrians.

E. Provide a bicycle detour route.

2. The Contractor shall ensure construction equipment, including signs and barricades, do not obstruct the bicyclist's path.

3. When steel plates are necessary on the bicycle way, the Contractor shall follow the requirements of Section II E. 6.

4. When exposed utility maintenance holes or lids are necessary, the Contractor shall follow the requirements of Section II E. 7.

5. When roadway grindings occur as part of a pavement rehabilitation project, the Contractor shall ensure the roadway surfaces are frequently cleaned or swept to minimize impacts to bicyclists.

6. For pavement or utility replacement projects, the Contractor shall avoid or minimize asphalt or concrete seam exposures (especially longitudinal seam formation) to bicyclists.

7. For vehicle lanes that continue through the work area the Contractor shall provide advance warning to bicyclists and motorists of any transition into and out of the vehicular travel lanes and allow sufficient lane width to accommodate both.

8. For vehicles lanes which continue through the work area the Contractor shall consider auto travel speed, grade, pavement condition, length of work area, lighting, and sight distance to determine if lane widths are sufficient to accommodate both motorists and bicyclists.

9. The Contractor will avoid requiring bicyclists to dismount their bicycles while traversing a work area whenever feasible, and will provide advance notice and a flagger to bicyclists regarding alternate routes when bicycling through the work area cannot be safely accommodated.

10. Maintain 5' minimum bike lane widths, for both the bike lane and buffer combined.

C. Bicycle Facility Closures, Detours and Alternate Routes

If the City Traffic Engineer determines that temporarily closing a bicycle facility traversing the work area is required for the safety of bicyclists, such closure requires the same level of signage and traffic control design considerations as when a motor vehicle lane is closed.

The Contractor shall include a bicycle facility closure and detour plan in the proposed traffic control plan for review and approval by the City Traffic Engineer before closing any bicycle facility. Approved signs, markings, and traffic control shall be used when a detour is required.

Determination to close a bicycle facility and to provide a well-signed detour route will include consideration of the needs of all bicyclists who use the bicycle facility under normal conditions, including daily commuters as well as recreational and novice bicyclists. The conditions to be considered to close a bicycle facility and provide an alternate route include:

1. Removal or reduction of existing street and/or bicycle lanes through the work area and the ability to effectively transition bicyclists into and out of vehicular traffic; for merging the bicyclists into the street travel lane a flagger is required;

2. Vehicle and bicycle travel speeds;

3. Taper length for bicycle transition to the travel lane;

4. Grades, and bicycle ramps applications;

5. Frequency and extent of pavement grindings, potholes, and/or utility lids;

6. Length and duration of work area;

7. Vehicle volumes; and

8. Lighting and sight distance.

The City Traffic Engineer may determine that bicycle safety is adequate to maintain bicycle access through the work area but may require additional bicycle alternate routes.

The following shall be considered in the development of a bicycle detour or alternate route:

1. The bicycle detour or alternate route should parallel the existing bicycle facility impacted by the work area and minimize detour distance to the extent possible.

2. The bicycle detour or alternate route shall be maintained and regularly monitored (clear of debris and signs maintained) during the course of construction or other planned work in the right of way.

3. Adequate signage shall be used in advance of each approach to the bicycle detour or alternate route, and shall be posted at least 5 days in advance of the closure. http://sdotblog.seattlemultiqa.wpengine.com//wp-content/uploads/sites/10/2016/10/BikeLane_Greenway_Impact_FactSheet.pdf

4. Where bicycle detours or alternate routes are expected to create a significant change in bicycle volumes on a detour or alternate route, appropriate directional and warning signage for bicyclists and motor vehicles shall be installed.

5. The bicycle detour or alternate route shall avoid any railroad crossings, Streetcar tracks, and any tripping hazards for the bicyclists.

6. If bicycle detours to the sidewalk or any shared used path, a minimum width of 10' is required.

VIII. DETOURS AND STREET CLOSURES (Figure VIII 1)

Several elements, in addition to those indicated in Chapter I, are involved whenever it is deemed necessary to close an existing street and create a detour.

A. Permission and Notification

Notification to close a street shall be given to and permission obtained from the Seattle Department of Transportation (SDOT) Transportation Operations Division, as outlined in Chapter II of this Manual. The Contractor or Utility shall submit detour schedules and diagrams showing the steps required to maintain the detour during each phase of construction and showing the type, number, and placement of all traffic control equipment. The submittal shall include a tentative schedule indicating when specific signs, barricades, and pavement markings will be activated and deactivated.

B. Detour Requirements

All detours shall meet the following requirements in addition to any specified by the City Traffic Engineer as being necessary for a project:

1) The detour shall be as simple and direct as possible.

2) No turns shall be used on the detour other than those required to leave or enter the closed street or the parallel detour route.

3) Streets less than 36' in width shall be used to detour only one direction of traffic unless parking on one or more sides is restricted.

4) All detour routes shall be protected by the proper temporary traffic control signs.

5) When detouring a multi lane street onto routes less than four lanes in width, parking shall be prohibited on the detour route.

6) The detour route shall be clearly marked where it intersects other streets so that drivers will not turn prematurely into the construction area or closed portion of the street.

7) Arterial streets shall be detoured to arterial streets unless otherwise approved by the City Traffic Engineer.

8) Advance Warning signs to detours shall be used on arterial streets.

9) All temporary traffic control equipment used shall conform in design and placement to requirements set forth in this manual.

10) All temporary traffic control equipment used shall be supplied and maintained by the Contractor and adjusted as work progresses.

In addition, the Contractor shall be responsible for:

1. Posting signs and barricades advising of the street closure at the nearest intersections away from the closed portion of the street and on all cross-streets to minimize unnecessary backing, turning around, and maneuvering. Normally, such street closings should not exceed two blocks in length at any one time.

2. Providing and maintaining access for adjacent residents and business as much as conditions permit.

3. Maintaining access for all emergency vehicles, fire hydrants, and alarm boxes along the closed route at all times.

C. Requirements Within Streets Closed to Through Traffic

When construction work is being conducted on a street that is closed to all but local traffic, the requirements for signing, particularly advance signing, channelizing devices, lighting, and work area protection may differ from those indicated in this manual.

Generally, the following guidelines should be adhered to; however, each situation should be evaluated based on traffic volume and speed, familiarity of motorists with the roadway, and sight distance.

1. All open excavations, ditches, spoil banks, etc., within or adjacent to the right of way shall be properly marked with barricades. Also, obstructions such as poles, curbing, etc., which due to the construction are in a position where they could be struck by a vehicle or bicyclist should be properly identified by barricades, drums, etc.

2. The path of the vehicle through the construction area should be properly identified by channelizing devices especially where the route has been altered or existing paint striping or channelization has been obscured or removed due to the construction activities. This is especially important at night.

3. Where equipment is working in the traveled way during the daytime, advance signing is generally not necessary nor is delineation of the extent indicated in the illustrations. Generally, traffic cones or barricades outlining the immediate work area are sufficient to guide the motorists around the obstructions.

4. Where one lane must be used for two directions of travel a flagger shall be used. Where flaggers are deemed necessary, conformance with requirements discussed previously shall be adhered to. Situations as stated above which require flagger control shall be allowed during daytime only. At night, such areas shall be clearly marked to allow two lanes of traffic.

5. All signs, channelizing devices, and other equipment used for traffic control at night shall be properly reflectorized or provided with warning lights as indicated previously in this Manual.

6. Where equipment is intermittently backing into the traveled way, flaggers are not generally needed provided that traffic volumes are light, speeds are low, and adequate sight distance is available to allow a vehicle to stop safely if necessary.

IX. EMERGENCY WORK

Emergency work is defined as that work which must be done immediately. By its nature it cannot be pre planned; however, standard procedures and requirements shall apply whenever practical.

The person responsible for the emergency work shall at the earliest possible opportunity notify the Seattle Department of Transportation 24-hour Dispatch at (206) 386-1218.

X. ENFORCEMENT

It shall be the responsibility of the Contractor to comply with the requirements of this manual. Should said person fail to comply, the City Traffic Engineer or his agent or a Street Use Inspector shall have the authority to stop all work until compliance has been achieved. Such work will not be resumed until the necessary corrections have been implemented. Any work required by the City to achieve compliance with the manual shall be paid for by the Contractor. In addition, citations may be written to those directly responsible for the construction activities.

XI. BARRICADING AND SIGNING ILLUSTRATIONS

The illustrations contained herein are meant to indicate typical situations and utilization of the traffic control devices described in the text. Typical illustrations will not be reviewed or approved as a practical traffic control plan, the design is provided for guidance and document planning purposes only. The use of certain traffic control devices for specific situations is not intended to exclude the use of those traffic control devices for other situations. At all times, however, practices prescribed in the text shall be adhered to. The following is a list of procedures for placement of traffic control devices:

1. Advance warning signs may be placed on:

a. Portable sign supports

b. Posts

2. For night operations:

a. All channelizing devices shall be reflectorized. Cones shall not be utilized alone.

b. Through the taper section install arrow signs (W4-119) spaced at 3S. (See Table XI 1)

c. All signs shall be reflectorized, except those controlling parking and pedestrians.

d. Install a flashing yellow warning light on each high-level warning device.

e. Horizontal barricade or vertical panels shall have a flashing or steady burning light attached.

3. General notes:

a. Where possible, place a vehicle between the work area and the traffic flow.

b. Signs shall not be installed on Type I or Type II barricades.

c. The predominant color for channelizing devices shall be orange.

4. Set up (in order of occurrence):

a. Temporarily place a high-level warning device at the side of the road.

b. Place advance warning signs.

c. Place channelizing devices for traffic diversions (moving in the direction of traffic.)

d. Adjust placement of high-level warning device.

e. Protect the work area.

f. Place soil or equipment between traffic flow and work area when practical.

5. Pick up

a) Reverse set up procedure indicated in #4 above.