How to Create a Safe Work Zone Using Maintenance of Traffic
Balancing the need to keep workers safe and keep traffic flowing isn't always easy, but it can be done.
Working in an area that is close to live traffic is extremely dangerous. Even though drivers encounter road construction zones daily, they can still make mistakes and careless choices. With people being distracted, impaired, rushed, angry, or aggressive behind the wheel, injuries and fatalities continue to happen (for related reading, see Distraction, Fatigue, and Impairment: What Any Safety Professional Can Do).
It is essential, then, that any work being done on or near a road, including construction, repair, resurfacing, and even landscaping, have a clear and thorough traffic maintenance plan.
What's Involved in a Traffic Maintenance Plan?
A traffic maintenance plan must ensure the safety of workers while also considering the drivers, pedestrians, cyclists, and persons with disabilities. The plan must also take establishing factors into account, such as the duration and timing of the work (day vs. night), the location of the work (on the road or on the shoulder), and road and traffic conditions. It should then consider the services and guides that will be required, specifically law enforcement assistance, flaggers and sign crew, signage, and cones and drums.
For crews working in a road lane, the activity area must allow workers to safely operate their equipment, including swinging machinery like excavators and cranes. There must be adequate space for traffic to pass, with a clear barrier separating live traffic from the road crew. This is usually achieved by deploying cones, but in some circumstances, especially for long-term projects, the assistance of local police or moveable concrete barriers will be needed.
Four-Part Traffic Maintenance Zone
In general, a safe work zone uses a four-part traffic maintenance structure.
1. The Advance Warning Area
The advance warning area uses signs to inform motorists of the type of work ahead and the distance required to merge into one lane. Warnings should start well ahead to give traffic the time and opportunity to merge, as well as offset the need for fast braking. Detours, alternate route signage, and timing signs (approximating how many minutes of wait time) should be posted.
The advance warning area is the starting point for cone deployment from the shoulder to the edge of the road (called a shoulder taper). This is essential since some drivers may use the shoulder for emergency driving. The construction zone must start at the very edge of the driveable surface of a road.
Arrow panels, directional lighting systems, or flaggers may be required in his area.
2. The Transition Area
The transition area uses cones to form a “merging taper” that advances across a lane to force traffic into the remaining live lane. It should also clearly establish the lateral buffer area to ensure sufficient space between the traffic and the workers on either side of the cone barrier. Planners should consider allowing sufficient space for wide trucks and inexperienced drivers of large vehicles like RVs.
To calculate merging tapers, use the following formula:
- For posted road speed limits of 40 mph or under: L = WS2/60
- For posted road speed limits of 45 mph or over: L = WS
- L = taper length in feet
- W = width of lane or offset in feet
- S = posted speed, or off-peak 85th percentile speed in mph
3. The Activity Area
The activity area is the zone in which the construction work occurs.
The first part of the activity area should be a buffer area, providing a space of protection for workers and traffic. The second part is immediately adjacent downstream, and is the zone for workers, machinery, and storage.
4. The Termination Area
Finally, the termination area is the end zone of the construction, and should include a short 100’ taper of cones back to the shoulder to clearly indicate the official end of construction.
Some sites simply stop the cones without a taper. But as with all road safety, clear indication is a better practice.
(To learn more, see Work Zone Awareness.)
Entrances and Exits for Construction Trucks
Construction zones may also require entrance and exit gates for dump trucks and other vehicles. These may require breaks in the cone barrier and must be clearly marked as entrance or exit gates, including instructions to truck drivers to never stop immediately upon entering (in case another truck is following).
Flaggers and Alternating Direction Lanes
On smaller, single-lane roads like an east-west road with one lane for traffic in each direction, if the westbound lane is closed for construction, the eastbound lane will have to alternate between eastbound and westbound traffic. This will require flaggers at each end who can communicate by radio or line of sight to ensure their "SLOW" and "STOP" signs are coordinated. This will ensure a safe, smooth flow or unidirectional traffic.
General Safety Tips
To keep a work zone safe while maintaining traffic flow, workers should always ensure that their activity takes place within the work zone and never in the live traffic lane. Whenever possible, work should be done facing the oncoming traffic. Any vehicles that need to reverse while in the work zone must do so with visual and audible warning devices, and ideally with the assistance of a flagger.
Pay attention to visual dangers like work lights and dust. Both may affect the ability of oncoming drivers to see clearly. Watch also for road cones or drums that may have been moved or hit, which creates a hazard in live lanes.
Nighttime construction and rain always add to the danger of a work zone due to reduced visibility. Be prepared for these conditions and adjust your approach accordingly.
Appoint one individual per shift to take stock of accidents or near misses, for compliance and insurance purposes, but also to improve safety in the future.
Working near traffic is always risky. But by balancing the needs of the work crew and the drivers, you can reduce risks and help workers get through the day unharmed.
More from AD Safety Network
- When should you consider using custom molded earplugs?
- At what height do falls become deadly?
- Who should be responsible for rescuing fallen workers?
- What kind of training do loading dock workers need?
- How often should I inspect a loading dock?
- How is wind chill calculated?
- What is the difference between occupational safety and process safety?
- Why should rubber insulating gloves be tested?
- What happens if I tie off at the foot level with a personal SRL?
- Why is testing with a NAIL4PET accredited lab important?
- What kind of face protection do I need when using a chainsaw?
- What is the permissible exposure limit (PEL) for silica?
- What is silica and why is it hazardous?
- What is 'Table 1' and why is it so important?
- Video Q&A - What is a safety policy?
- What kind of fire extinguisher is best for your work site?
- How do I choose the right respirator and mask for working with silica?
- Can I wear fall protection equipment over my rainwear or winter gear?
- When do I need a cage ladder?
- What types of gloves protect your hands from hazardous chemicals?
- How come I still got hurt while wearing flame-resistant clothing?
- What dangers do workers face when working outside in the winter?
- How do I win over my most reluctant employees?
- What kinds of jobs should use disposable safety gloves?
- Is it true that safety shouldn't be a top priority?
- When are employers allowed to conduct drug and alcohol tests on their employees?
- How can I get employees more involved in the risk assessment plan?
- What are some of the indirect costs of accidents?
- How often do fire extinguishers need to be inspected?
- What is the best way to store rubber safety gloves?
- How much voltage protection is needed for safety gloves used in electrical work?
- What is the difference between a safety valve and a release valve?
- When do workers have the right to refuse to work?
- What is the most overlooked item when designing Lockout/Tagout (LOTO) procedures?
- What are some of the misconceptions about heat stress and what should we do to address them?
- What tools should I tether when working at heights?
- What types of gas should I watch out for when working in a confined space?
- How do you create a culture of safety in your workplace?
- What is the difference between industrial safety and industrial hygiene?
- Is it important to get PPE assessments by trained professionals?
- What is a fault tree analysis?
- What kind of respirator cartridge should I use?
- What are the safety benefits of a whistleblower program?
- What type of safety record-keeping and recording should we be doing?
- What makes a hi-vis safety vest ANSI compliant?
- Why is it important to have air sampling done to determine my PELs?
- What is the life expectancy of fall protection equipment?
- What are hot work and cold work permits?
- What are some basic fall protection rules that each of my workers need to understand?
- How much clearance do I need to safely use a Leading Edge SRL?
- What is the difference between an acute hazard and a chronic hazard?
- What’s the difference between a bump test, a calibration check, and a full calibration?
- Is there any legislation regulating lone worker safety I should know about before hiring?
- What kind of fire extinguisher and accessories should be kept on hand on a factory floor?
- What can companies do to reduce their lost time injury frequency rates?
- Video Q&A - What's your safety network like?
- Video Q&A - What are the 3 levels of safety?
- Video Q&A - How do you treat a near miss?
- Does body weight affect falls differently?
- What ages are most affected by falls?
- Why do workers take risks?
- What Is the Difference Between OHSAS 18001 and 18002?
- What is the difference between lost time injury and medical treatment case?
- What is the difference between occupational health and safety and workplace health and safety?
- What is the difference between occupational health and occupational safety?
- What is the difference between a lost time injury and a disabling injury?