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Work Zone Safety - Frequently Asked Questions

Cones, barrels, and barriers

Q.  Why do you close off a long stretch of roadway when work is only being done in a short section?

A.  There are many reasons why a given length of roadway is closed, but the main reason is that work is being conducted to maximize productivity even though it may appear to the driver that little or no work is in progress at any given time. Remember, the work zone is usually observed by the driver for a very short period of time. Roadway work is very dynamic with several ongoing work operations synchronized to result in a finished product. This is usually true for both long and short duration work. Also, it is generally more efficient and safer to implement the traffic control for the entire length of the work zone.

Common work operations that are not always observed:

  • Survey and layout work
  • Preparation work, such as sweeping and cleanup
  • Preliminary repair work operations
  • Utility relocations
  • Related individual work operations done in advance of the main work effort

Q.  Why do you close off three lanes when work is only being done in one?

A.  In many cases it is not feasible or safe to conduct work operations within the limits of a single lane. Maintaining traffic directly adjacent to a work operation, separated only by a lane stripe is extremely hazardous for both drivers and workers. Longer term projects may use temporary concrete barrier to separate traffic from the work zone. Our practice is to close the minimum number of lanes to safely and effectively pursue the work. Also, lane closures are analyzed for traffic delay impacts and every effort is made to minimize traffic impacts as much as possible.

FYI ... the length of a work zone (freeway lane closures) has a minimal effect on traffic delay ... most of the delay is generated at the actual lane closure taper. (A taper is a series of traffic control devices that move traffic out of or back into its normal path.)

Q.  Why are long lane closure tapers are needed?

A.  Lane closure tapers are designed to accommodate safe and efficient merging. The major consideration is traffic speed - the higher the speed the longer the taper. A common freeway lane closure would use a minimum 720’ taper for 60 MPH posted speed limit.

Construction signs

Q. Why do you post “Construction Ahead” signs when no work is going on?

A. WSDOT is legally obligated to post “Road Work Ahead” or other warning signs as needed at work zones. Even though there may be no obvious work activity, there probably is some minor work underway or the condition of the roadway may have been changed due to previous work. We want to ensure that drivers are aware that they are in a work zone and are alert to any work zone conditions (even minor conditions) that might not be present under normal operational conditions.

Q. How far in advance (time) do you post notice of a ramp closure?

A. There is no fixed time limit, but we do use guidance based on traffic and site conditions as well as past experience on what is a reasonable time period to alert drivers that a ramp will be closed. Short term closures for a few hours or overnight normally only need short notice of about 3 days, and less if there is an urgent need or emergency requiring a ramp closure. Long term closures are scheduled as far in advance as possible and one to two weeks of advance notice may be required. Also, long term closures may be announced in local newspapers or other news media along with the advance notice of closure signs.

Q. Why don’t you post signs far enough ahead of the work area so that we can take a detour/avoid a backup?

A. This is usually considered as part of the planning and design for work zones. Unfortunately the length of a backup can be difficult if not impossible to predict on any given day. WSDOT has started to use portable changeable message signs (PCMS) in response to backups in an effort to provide an alternate route. Permanent variable message signs (VMS) are also used if their location to the work zone and alternate route is suitable. Also, new technology is becoming available that will allow us to monitor work zone backups and remotely send real time messages to PCMS’s strategically located in advance of alternate routes.

Q. I passed a lane-closed sign, everyone was moving over, and there was no one working – what’s up with that?

A. This does happen and is usually due to setting up or taking down work zone signs and devices. Many work zones can be labor intensive to install and remove, and can take 1 or 2 hours depending on the size and complexity. If a driver happens to be traveling through a work zone during these periods the work zone may not be fully operational. Occasionally, a sign may be inadvertently left in place when it is not needed, and we try to respond as soon as possible if this happens.

Q. What are the different kinds of signs you use in work zones?

A. Work zones are commonly identified by orange warning signs. Many work zones also use a full compliment of standard road signs as listed below. Remember all rules of the road apply in work zones, including compliance to the posted signs.

  • Orange work zone warning signs
  • Orange safe speed advisory signs (curves, rough roadway, etc.)
  • Black on white regulatory signs
  • Portable Changeable Message Signs (PCMS)
  • Variable Message Signs, permanent (VMS)
  • Temporary guide and directional signing (green or orange)
  • Road and ramp closure signs

FYI ... double fines are imposed for exceeding the speed limit in work zones.

Night work

Q. Why isn’t all construction done at night and how is it decided when it is appropriate?

A. Quite a bit of construction work is done at night in an effort to avoid the higher volume daytime hours and associated traffic delays.  This may be the only positive benefit of night work, but a very important benefit nonetheless. Not all construction work is compatible with night work and some construction work cannot physically be completed at night and reopened the following day. If traffic can be maintained at a reasonable level, we would prefer to conduct work during the day for the following reasons:

  • Night work is inherently more dangerous due to the reduced visibility and the much higher percentage of impaired drivers.
  • Production and quality can suffer to some extent because of the difficulty of working under low light and portable light conditions.
  • Night work generally is more expensive due to less production and increased traffic control, lighting and protective measures.
  • Some projects have very restrictive noise ordinances which limit work hours or require additional noise reduction measures.

This is a complex issue and the above information does not totally capture all the elements. We will continue to rely on night work in many of our urban and other high volume work locations simply because the traffic impacts of daytime work would be unacceptable.

Driving tips

Q. What is the proper way to merge when approaching a freeway construction zone?

A. The key issue here is courtesy. Safe and efficient movement of traffic through the merging area approaching a work zone lane closure depends on the merging drivers ability to plan ahead, adjust speed and merge into a safe gap between vehicles in the open lane. Merging is much easier and safer when all drivers act in a courteous manner and work together. Legally, the burden is placed on the merging driver to merge in a safe manner. It is illegal for drivers in the open lane to actively block merging traffic.

Q. When should I move over when there is a lane closed ahead?

A. Start planning ahead as soon as you can determine which lane is closed. There is no need to abruptly change lanes or merge into the open lane far in advance of the lane closure. Start looking for a safe gap between vehicles in the open lane and merge into that gap in a smooth manner. It is legal to merge into the open lane right up to the actual lane closure taper of devices, but it is recommended to give yourself some additional space and merge somewhat sooner. This will allow a margin of safety in the event that you may not be able to merge as soon as expected.

Q. What’s the best thing to do if my vehicle breaks down in a construction zone?

A. Don’t panic, usually help will be on the way soon. Stay in your vehicle if you are in a traffic lane, turn on the vehicle flashing hazard lights and call 911 if you have a cell phone. At the first indication of a problem with your vehicle, drive to a shoulder or off-ramp, if at all possible. If it is safe to get out of your vehicle, raise the hood, call and/or wait for help.

Q. What should I do if I get in an accident in a work area?

A. An accident can be a traumatic event even without serious injuries, but remain as calm as possible and stay in your car. If it is possible to move your car out of the traffic lane to a shoulder or other safe area, turn on the flashing hazard lights and do so. Call 911 if you have a cell phone and/or wait for help. Help should arrive soon.

FYI ... if your vehicle becomes disabled or damaged in a work zone, be extremely cautious if you exit the vehicle even if you are on the roadway shoulder. You may be exposed to high speed traffic hazards as well as potential hazards within the work zone that are not intended for pedestrians, such as;

  • Shoulder drop-offs or other unprotected drops ... be extremely cautious if you cross over a barrier, there may be nothing to support you on the other side.
  • Rough walking surface, repair areas, etc.
  • If you are on a section of elevated roadway or bridge, do not cross over any protective barriers, there is probably nothing to prevent you from falling on the other side.


Q. Why do you need so many vehicles, when only one or two people are doing work?

A. Many roadway work operations are mobile and may be constantly moving ahead or from one location to another. In an effort to be as efficient as possible we try to expedite the work through the use of specialized equipment that improves work production. Chances are the workers you see are just part of a larger crew that is operating the other vehicles. In many cases it takes as many as three additional vehicles to perform the traffic control which allows the main work operation to proceed.

Q. Why do you need to close a bridge for inspection?

A. This really depends on the type of bridge and how extensive the inspection is. In most cases we do maintain traffic at some level with lane closures. If there is a major inspection effort or a safety concern (such as after an earthquake) the bridge may have to be closed.