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Work Zones 101

A work zone with barricades and a road closed ahead sign.
Department of Transportation

Work Zones 101

Work zones play a significant and important role in building and maintaining our state's roads and bridges. To keep Michigan's road crews safe and free from injury and death, it is important to understand the how and why of work zones.

Travel with us as we explain the different aspects of a work zone and why slower speeds and following signs can save lives!

Work zone roadmap stop nine.

Screen shot of MDOT's Mi Drive construction and traffic application.

Work Zone Notification

Know before you go! Mi Drive is a construction and traffic website that provides information about current and future traffic impacts. 

MDOT's Mi Drive website makes it easy to view traffic cameras and speeds, locate incidents and search construction projects - helping motorists know before they head out the door. Visit before hitting the road to stay up to date on construction on your commute.

A cement mixer, work zone barrier, clock and clip board depict the staging and the start of construction.

Staging & Starting Work

Do you ever notice lane closures, or cones and barrels along the roadway but no work taking place? There are several reasons why you might not see work occurring as you pass by:

  • Safety meetings often take place daily during morning rush hour to avoid peak traffic, which minimizes motorists delay.
  • Trucks removing materials may be in between trips as you pass by. 
  • You may be passing through before or after scheduled work hours.
  • Current or future weather conditions may lead to delayed start times or even cancelation of work, depending on the work types. 
  • Concrete may be curing.

When driving to and from work you are most likely spending about 15 minutes per trip in the work zone. The 30 minutes you spend driving by a work zone only accounts for 2% of the time work could be taking place during a 24-hour timeframe. Construction projects often occur round the clock or stage high-impact operations outside peak travel times. Work zones are constantly changing, so stay alert because the next time you pass through, workers may be on site. Slower speeds save lives!

Work Zone 101 Stop 3 showing merging signs in a work zone.

Know Your Signs

Do you know what these signs mean?

In the image on the left, the sign tells us to watch for traffic merging into the right lane.  It is the responsibility of merging traffic, in this case the yellow car, to adjust speed to find an acceptable gap in which to merge.  However, the thru motorists, like the green car, could change lanes to the left or adjust speed to accommodate merging traffic.

In the image on the right, the sign is intended to alert the motorist of the possibility of entering traffic.  In this scenario, the blue car will have a dedicated lane and merging is not necessary.

A portable changeable message sign board that reads Road Work Ahead and two static work zone signs.

Backups & Congestion

Even with the best planning, backups and congestion can happen during road construction. This congestion can lead to dangerous situations for both motorists and construction workers, especially when drivers are distracted.

Next time you drive through a work zone, remember these statistics, and do your part to keep drivers and workers safe by eliminating distractions and focusing on your most important task - safe driving! 

  • Motorists are more likely than workers to be killed or injured in work zone related incidents. 
  • The leading causes of all work zone related crashes are driver distraction and speeding.

Slow down. Stay focused. These two simple steps may save your life or the life of a road worker.

Reduce Speed Ahead with police car lights.

Speed Limits

Speeds are reduced for safety and because lane widths, shoulder widths and merging areas may be reduced to provide space for construction. Plus, slowing down can provide you with extra time to react to changing road conditions.

Slow down. Give yourself extra time. The life you save could be your own!

A graphic of a car with duct tape and wrenches near.

Fix Types

Some road projects may start and end within a matter of weeks while others take an entire construction season (or two!) to complete. What’s the difference?

Short-term projects are most often repair type projects, such as filling potholes or resurfacing a rough stretch of road. These types of projects are lower in cost but can’t possibly last as long. 

Rebuilding a road completely, including all pavement and base materials takes more money and time, but will also provide long-lasting results.

Closure Types

Work zone traffic plans are designed to allow enough room for the construction work to take place AND protect workers and road users. Engineers review each project and select the most appropriate closure option based on traffic volume, location, type of work, and other factors.

Single-lane closures
A single-lane closure is the most common type of closure. This type of closure allows motorists to use the road while the road work is taking place. You may have encountered a lane closure, new concrete, and no workers. Don’t worry, we didn’t forget about it – we are just letting the concrete cure! Concrete requires a specific amount of time to harden and strengthen before traffic can drive on it again. 

Nighttime and weekend lane closures
Work that occurs at night or during weekends is usually done because traffic volumes are lower, which means fewer traffic backups and delays.

Total closures
A total or full closure means the road is closed and an alternative route must be used. A total closure may be used for projects such as bridge moves, beam setting, and full reconstructions. Total closures help improve the safety of workers and motorists, reduce congestion, delays, and crashes, as well as expedite project completion.

Watch an MDOT bridge move with a total closure
A graphic of work zone equipment.

Construction Equipment

There are many different types of construction equipment used in work zones, but there are also life-saving devices that many road users may not know about. Truck-mounted and impact attenuators are designed to absorb collision energy during a crash – saving lives and reducing expensive equipment damage.


A graphic of an active work zone with equipment, barricades, and signs.

Holiday Shutdown

MDOT suspends work and lifts traffic restrictions wherever possible during the Memorial Day, Fourth of July, and Labor Day holidays in order to ease congestion and increase safety.

However, there are times when it is not feasible (equipment or barrier walls) or safe (excavation sites or a bridge that is out) to suspend work zone restrictions. In those cases, traffic configurations will remain and motorists must obey all work zone and speed limit signs.