Traffic Control Devices & Placement Requirements

Proper use of road closure barriers is essential for maintaining public safety and traffic control during special events. Barriers are required to ensure pedestrian safety, restrict vehicle access, and direct traffic efficiently. The type of barrier required depends on the size, location, and impact of the event.

Types of Road Closure Barriers

  • Description: Lightweight wooden or plastic barriers with one reflective panel on the top rail.

    Common Uses:

    • Minor road closures

    • Sidewalk or pedestrian detours

    • Parking lot closures

    Placement Requirements:

    • Used for short-term or low-impact closures

    • Must be set up in a continuous line or staggered for maximum visibility

    • Should be spaced no more than 10 feet apart for effective road closure

  • Description: Similar to Type I but with two reflective panels for increased visibility.

    Common Uses:

    • Lane closures on local streets

    • Sidewalk closures near intersections

    • Blocking minor intersections

    Placement Requirements:

    • Positioned to be visible from at least 200 feet away

    • Used in areas with moderate pedestrian or vehicular traffic

    • Must be anchored to prevent movement from wind or pedestrian impact

  • Description: Larger, more robust barriers with three horizontal reflective panels.

    Common Uses:

    • Full road closures

    • Freeway or arterial lane closures

    • Events requiring emergency vehicle access control

    Placement Requirements:

    • Placed at primary road closure points with "ROAD CLOSED" signage

    • Must be at least the full width of the roadway to prevent vehicles from passing through

    • Requires anchoring or sandbags in high-wind areas

  • Description: Large, interlocking plastic barriers that can be filled with water for stability.

    Common Uses:

    • High-traffic areas needing enhanced security

    • Protecting event perimeters from vehicle threats

    • Dividing lanes for pedestrian safety zones

    Placement Requirements:

    • Must be filled with water before the event starts

    • Placed in a staggered formation for better impact absorption

    • Requires reflective striping or signage for nighttime visibility

  • Description: Heavy-duty reinforced concrete barriers designed for vehicle impact resistance.

    Common Uses:

    • Major road closures on highways or high-speed roads

    • Critical infrastructure protection

    • Events with high pedestrian traffic near roadways

    Placement Requirements:

    • Requires professional installation with a crane or forklift

    • Must be set at least 10 feet apart for emergency vehicle access if needed

    • Not suitable for short-term closures due to weight and setup logistics

  • Description: Flexible cones or posts with reflective surfaces for temporary traffic control.

    Common Uses:

    • Temporary lane closures

    • Diverting vehicle or pedestrian flow

    • Marking hazardous areas

    Placement Requirements:

    • Spaced every 10-15 feet for lane closures

    • Must include reflective tape for nighttime visibility

    • Should be accompanied by flashing lights in low-light conditions

  • Description: Metal or plastic interlocking barriers designed for pedestrian control.

    Common Uses:

    • Separating pedestrian and vehicle zones

    • Managing crowd control near entertainment areas

    • Keeping restricted areas secure

    Placement Requirements:

    • Must be interlocked to prevent gaps or movement

    • Should be reinforced with sandbags in windy conditions

    • Minimum height requirement of 42 inches for pedestrian safety

Placement Guidelines for Road Closure Barriers

The placement of barriers is critical to ensuring a safe and effective road closure. Here are key guidelines for proper placement:

    • Use: Type III barricades, water-filled barriers, or concrete Jersey barriers.

    • Spacing: Must fully block all lanes to prevent unauthorized vehicle access.

    • Signage: Must include "ROAD CLOSED" and detour signs at least 200 feet in advance of the closure.

    • Emergency Access: Maintain a 20-foot clearance in case of emergency vehicle passage.

    • Use: Type II or III barricades, cones, or water-filled barriers.

    • Spacing: Cones should be placed every 10-15 feet to guide vehicles.

    • Signage: Must include "LANE CLOSED" or directional signage.

    • Use: Type I or Type II barricades with pedestrian detour signs.

    • Spacing: No more than 10 feet apart for clear marking.

    • Signage: Must indicate "SIDEWALK CLOSED – USE OTHER SIDE" where applicable.

    • Use: Type III barricades at key intersection points with detour signage.

    • Spacing: Must be placed to prevent vehicles from entering restricted streets while allowing alternative traffic flow.

    • Signage: Should include clear detour instructions for drivers and pedestrians.

    • Use: Water-filled barriers, concrete Jersey barriers, and pedestrian barricades.

    • Spacing: Barriers must be staggered to create a chicane effect (forced turns to slow vehicles).

    • Signage: Must be highly visible with "AUTHORIZED VEHICLES ONLY" designations if applicable.


Additional Requirements for Road Closures

    • All barriers used at night must have reflective tape or flashing warning lights.

    • Barriers on major roads require at least two warning signs placed 200-500 feet before the closure.

    • Event organizers are responsible for checking and maintaining barricades throughout the event.

    • Barriers must be inspected regularly to ensure they remain in place and effective.

    • All barriers must be removed promptly after the event.

    • Any damage or improperly placed barriers must be reported immediately.

Types of Road Closure & Detour Signs

    • Purpose: Used to indicate a full road closure, restricting access to all vehicles except authorized personnel.

    • Specifications:

      • Size: Minimum 48" x 30"

      • Color: White background with black lettering

      • Placement: Positioned at the closure point and at key intersections leading to the closure

      • Additional Requirements: Must be accompanied by Type III barricades for full closures

    • Purpose: Used when local traffic is permitted beyond the closure point, but through traffic is restricted.

    • Specifications:

      • Size: Minimum 48" x 30"

      • Color: White background with black lettering

      • Placement: 200-500 feet before the closure point to allow vehicles to reroute

      • Additional Requirements: Should be placed on a barricade or post-mounted for visibility

    • Purpose: Informs drivers that only local residents, businesses, and emergency vehicles can access the closed roadway.

    • Specifications:

      • Size: Minimum 48" x 30"

      • Color: White background with black lettering

      • Placement: At entry points to closed roads or restricted zones

    • Purpose: Directs traffic to an alternative route when a road closure is in place.

    • Specifications:

      • Size: Minimum 36" x 24"

      • Color: Orange background with black lettering and an arrow indicating the detour direction

      • Placement: At every key turn on the detour route to guide drivers effectively

      • Additional Requirements: Must be used in combination with advance warning signs

    • Purpose: Provides advance notice to motorists about an upcoming road closure.

    • Specifications:

      • Size: Minimum 48" x 48"

      • Color: Orange background with black lettering

      • Placement: 500-1000 feet before the closure, depending on the road speed limit

    • Purpose: Notifies pedestrians that a sidewalk is closed and provides alternative routes.

    • Specifications:

      • Size: Minimum 36" x 24"

      • Color: White background with black lettering

      • Placement: At both ends of the closed sidewalk and at nearby crosswalks for rerouting

      • Additional Requirements: Should include an ADA-compliant pedestrian detour sign if necessary

    • Purpose: Indicates that a bike lane is closed and directs cyclists to an alternate route.

    • Specifications:

      • Size: Minimum 30" x 24"

      • Color: White background with black lettering

      • Placement: At the start of the closed bike lane and at each major intersection along the detour route

Placement Guidelines for Road Closure & Detour Signage

    • “ROAD CLOSED AHEAD” signs must be placed at least 500 feet before the closure for roads with speeds under 35 mph, and 1000 feet before closures for roads over 35 mph.

    • “DETOUR” signs should be placed at the first available turn before a road closure to allow drivers time to change routes.

    • Signs must be placed at a height of at least 5 feet above the ground to ensure visibility for all road users.

    • Multiple signs should be used for roads with more than two lanes to ensure visibility from all directions.

    • Retroreflective materials should be used for nighttime visibility.

    • First “DETOUR” sign: Placed at the initial closure point.

    • Subsequent “DETOUR” signs: Placed at every major turn along the detour route.

    • “END DETOUR” sign: Placed at the final point where the detour rejoins the main road.

    • If the road closure permits emergency vehicle access, signs should include “EMERGENCY VEHICLES EXEMPT” messaging.

    • In areas with heavy pedestrian traffic, additional “PEDESTRIAN DETOUR” signs should be installed to guide foot traffic.

Best Practices for Effective Signage Management

    • Before placing signage, review the detour route and identify critical points where additional signs may be needed.

    • Regularly check for any displaced, damaged, or vandalized signs during the event.

    • Work with the Tacoma Public Works and Traffic Engineering divisions to ensure that detour plans align with citywide traffic management efforts.

    • Pedestrian detour signs must include accessible pathways for individuals with disabilities (6 foot minimum)

City of Tacoma Traffic Control Handbook
Barricade / sign index