Lesson 3: The Work Zone
Aim: After completing this lesson you will be able to name and describe the primary parts of the work zone.
Your exposure to being hit is the greatest when you are placing or removing traffic control devices in the work zone, so be alert. When setting up the work zone, make sure that all signs and devices are in place before you start any work. First, put up the advance signs in both directions, then position the flagger if there will be one, then complete the transition and work zone channelization areas. Move with the traffic whenever possible, except when closing down the work zone. Pick your traffic controls up in reverse order, starting with the End Road Work sign and working towards the Road Work Ahead sign.
The work zone typically consists of 5 parts:
1. Advanced Warning Area
- This area is the most important since it:
- Gets the public's attention
- Informs the driver of what to expect ahead
- Provides the driver time to react
The Advance Warning Area should use three types of signs:
- General warning (ROAD WORK AHEAD)
- Specific warning (ONE LANE ROAD AHEAD or RIGHT LANE CLOSED AHEAD)
- Specific instructions (FLAGGER AHEAD)
At higher speeds, space the signs 500 feet apart
At lower speeds, space the signs at least 100-350 feet apart
Locations of signs, flaggers, and tapers should be adjusted for field conditions that make them hard to see, such as trees, curves or hills.
|Road Type||Distance Between Signs|
|Urban ≥45 mph||350 feet|
|Urban 35-40 mph||200 feet|
|Urban ≤30 mph||100 feet|
2. Transition Area
Narrow pavement, reduction of travel lanes, or a lane closure may require moving traffic out of its normal path. The transition area is where the change in traffic flow occurs, often using cones or barrels. The area where the actual shift is made is called the taper. The length of the taper depends on the approach speed and the width of the shift.
The transition area should:
- Move traffic out of the normal path/flow
- Provide clear directions so that drivers know where to go
- Usually involve tapers
- Vary with speed and distance
3. Buffer Area
The unoccupied space between the transition area and the work area is the buffer area. This area should be free of all equipment, vehicles, and construction materials. It provides room to stop for drivers who do not see or who do not follow signs or flagger guidance. The length of this area varies depending on traffic speed, volume, and conditions.
|85th Percentile approach speed (mph)||Buffer space length (feet)|
The buffer area is:
- A safety factor in case a driver does not stop
- The place where you can adjust for hills and curves
- A place where vehicles and/or equipment are not allowed
4. Work Area
The work area is where workers and equipment are located. Channelizing devices are used throughout the area to keep traffic in the non-work lane.
Some work zone area safety suggestions are:
- Keep traffic out of the work area, moving with the normal flow
- Remind your workers to keep themselves and equipment out of travel lanes
- Caution flaggers to avoid drifting into the travel lane
- In some situations you may need a flagger to control or slow down traffic
- Be sure to deal with the side roads and business access
5. Termination Area
This area advises drivers that they are past the work site and may resume normal driving. It is good practice to put an END ROAD WORK sign here. A short down stream taper is also recommended. Five cones in 100 feet is fine.
The termination area:
- Lets drivers know the work zone is over
- Is usually a short taper
- Needs an END ROAD WORK sign if it is not obvious