Each year in the US, hundreds of workers are killed or seriously injured when vehicles crash through traffic control devices and enter a work zone. Workers are also struck by equipment operating within the work area. Whether it’s repairing streets, cleaning storm sewer catch basins, painting intersections, or rebuilding manholes, tasks that require workers to share the road with vehicles put them at risk.
A traffic control plan must be developed before the work begins to guide drivers through and around work zones. The traffic control plan must include:
Advanced warning to drivers of the work being done ahead
Placement of traffic control devices to clearly mark the work zone and channel traffic through it
·A return to normal traffic patterns as quickly, safely, and efficiently as possible
The traffic control plan must address these factors:
The type of roadway (number of lanes, divided or undivided highway, etc.)
Traffic volume and speed (approximate number of vehicles passing through and the speed of vehicles)
Type of work to be done and how long it will last (pothole repair, fix a broken water line, roadway line painting, etc.)
Type and number of traffic control devices and signs needed to make the work zone safe
Creating a buffer zone between workers and traffic is the best way to protect them. Set up detours or use barriers such as type 3 barricades or concrete barriers, which protect workers much better than cones or barrels.
Reducing the speed of traffic in work zones also provides a safer work environment for workers. Put down portable rumble strips or using a pilot car to guide traffic at reduced speeds through the work zone area.
Advanced Warning Signs should be located far enough in advance to allow vehicles to move efficiently and smoothly through work areas. They must clearly inform motorists of approaching activity and guide drivers through that activity.
All advanced warning signs must be:
Orange background with black lettering or symbols
Retro-reflective or illuminated if used after dark
4x4 feet if traffic moves at 45 mph or faster
3x3 feet if speeds are 40 mph or slower
7 feet above the road surface (measured to the bottom of the sign)
At least 1 foot above the road surface if the sign is portable
Less than 50% of the top two rails or not more than 33% of all rails if mounted on a barricade
Advance warning signs should be placed so as to give motorists enough time to react to the conditions they will find ahead of them. In general, the distance between the first warning sign and the work area should be increased the faster traffic is moving (Example: less than 40 mph = advanced warning sign 300 feet ahead; more than 45 mph = advanced warning sign 500 before work zone with at least 2 signs before entering work zone; add 100 feet for every 5 mph over 45 mph).
Traffic Control Devices such as cones, drums, barricades, tubular markers, and pavement markers are commonly used to alter or channel normal traffic flow. They alert drivers of work activities ahead and provide smooth and gradual traffic movement from one lane to the next. Cones, drums, and other devices must be made of lightweight materials and give way when struck by a vehicle. They must not break apart or be capable of penetrating the passenger compartment of a vehicle. The material used to weigh down devices (ballast) to prevent them from being easily blown over must also be made of materials that will cause only minimal damage to vehicles. Drums must be at least 3 feet tall and 18 inches wide, they must be orange and have 2 white alternating retro-reflective stripes. Stripes must be between 4 to 6 inches in width. The tops of the drums must be closed to prevent accumulation of debris. Steel drums are prohibited. Barricades are of 3 types and can be portable or fixed: Type 1 must be at least 3 feet tall with one rail 2 feet in length; Type 2 must be at least 3 feet tall with 2 rails 2 feet in length; Type 3 must be at least 5 feet tall, have 3 rails at least 4 feet long. The rails on all 3 types must be between 8 and 12 inches wide. They should be equipped with warning lights and the lights should be either steady burn or flashing. The stripes on barricades must be alternating orange and white with reflective striping. The stripes should slope down at a 45-degree angle in the direction traffic is moving. Striping should be at least 4 inches wide (If the rails are more than 3 feet long the stripes should be 6 inches wide.) There should be a minimum of 270 square inches of retro-reflective tape for on-coming traffic.
Laws to Protect Workers
The US Department of Transportation and the Federal Highway Administration have issued the Manual on Uniform Traffic Control Devices (MUTCD). OSHA enforces the MUTCD and it is part of OSHA’s standards for the construction industry (29 CFR 1926.200, 29 CFR 1926.203). For state and local workers not covered by OSHA, the Department of Transportation requires that the standard be followed on all public roadways.
It is the municipality’s responsibility and duty to comply with these standards to protect both workers performing duties in and on roadways, as well as drivers and pedestrians using those roadways.