Smart work zones are a type of traffic control technology configured specifically for a particular scenario. They are designed to enhance construction workers’ safety, advocate for motorists’ efficiency and provide computerized real-time information for a roadway work precinct.
Static message signs often do not give enough processed real-time information for motorists to make informed decisions in working zones. This can lead to increased driver frustration and unsafe driving behaviors.
Real-Time Traffic Information
Often, work zones are designed without enough consideration of how traffic will flow through them. This can lead to a number of problems including delays, congestion, and driver frustration.
This is why it’s important to provide drivers with real-time information on travel time, lane closures, and other traffic issues in work zones. This type of information allows drivers to plan their routes and reduces the likelihood of them panicking or speeding in the work zone.
To effectively communicate this information, Smart Work Zones utilize real-time technology such as sensors and crowdsourced data. The technology collects data about the current travel time, delay, and other traffic conditions, analyzes it in real-time, and then transmits this information to drivers.
The information is then displayed on dynamic message signs, such as portable changeable messages (PCMS) and digital message signs (DMS). This provides motorists with a real-time view of the traffic situation and how to respond.
Another way to improve traffic flow is by providing information about alternate routes that drivers can take when they encounter delays or congestion in the work zone. This helps drivers avoid backtracking and straying into the work area, which can injure workers and result in accidents.
In addition to providing this information, Smart Work Zones can also use queue warning systems that alert oncoming drivers of slow or stopped traffic. These systems have been proven to decrease accidents by more than 50% and significantly reduce the severity of crashes (7).
Using these technologies in combination with traditional traffic control devices can make a huge difference in the safety of construction workers and travelers during work zones. The technology can also help improve the flow of traffic during resurfacing and widening projects by reducing congestion, delays, and other issues that affect the overall operation of the highway.
The most effective work zones are those that have been designed and implemented in a collaborative manner by all of the disciplines involved. This includes traffic engineers, planners, contractors, and law enforcement.
To effectively implement a Smart Work Zone, it is crucial to start as early as possible in the planning process. This will allow the design team to identify any potential impacts that may arise from the project and develop the appropriate temporary traffic control devices to address those issues.
Travel Time/Delay Monitoring
Smart work zones use technology to provide real-time travel time and delay monitoring to motorists. This information reduces delays, crashes and fatalities, increases travel speeds and improves safety for all users of the roadway.
Smart work zone systems consist of sensors and portable changeable message signs that monitor road conditions and notify drivers of impending delays. The devices are usually placed upstream of the work zone, and when they detect slow or stopped vehicles, they send signals to the signs.
The system then displays warning signs to the motorists informing them that there are delays ahead and providing them with alternative travel options. It can be effective on rural highways, where congestion can often be unexpected by motorists.
One example of a system that uses this type of technology is Missouri DOT’s Rural Queue Warning System (RQDWS). This technology alerts high-speed motorists via dynamic message signs of upcoming slow or stopped traffic in a work zone.
In addition, it can increase driver safety by reducing the time it takes to merge into a work zone. This system can be especially beneficial during peak hours and for drivers traveling at higher speeds.
This system uses a series of sensors that measure, by individual lane, vehicle speeds, volumes and classifications. The data is then processed and compiled into a centralized data set that is distributed to various devices. The data can then be used for a variety of purposes, such as estimating the queue length upstream from the work zone taper, determining travel delays, and planning alternate routes.
Another benefit of this type of system is that it can help mitigate reoccurring congestion on roadways with high average daily traffic (AADT) levels, which is a common problem in work zones. This system can also be helpful in situations where lane restrictions are normally restricted to peak hour traffic.
The performance of work zone ITSs can be evaluated through many different metrics, including mobility/operational performance measures, safety performance measures and customer satisfaction. These metrics are important to evaluate the effectiveness of ITSs because they can identify whether or not these systems are meeting user expectations and performing as expected.
Queue Warning
During construction, traffic management is critical to ensuring motorist and worker safety as well as reducing travel delays. It’s especially important during lane closures that require drivers to change lanes or exit the road entirely.
In order to prevent this type of situation, traffic control experts need to provide real-time information to motorists about the expected time it will take to clear a work zone or how long they can expect to be delayed by a lane closure. Without this information, motorists may become frustrated and start to veer off the road into the work zone or brake suddenly, which can lead to accidents.
Queue Warning systems are a key component of Smart Work Zones and provide advanced warning messages that indicate slowed or stopped traffic ahead. They can reduce end-of-queue collisions (rear-end collisions) by up to 45%, according to a study from the Federal Highway Association.
When a queue warning system is deployed along a freeway, it includes sensors that measure the speed of vehicles upstream from a work zone or typically congested area and then relays that information to message boards or portable changeable message signs (PCMS) in real-time. Then, if a driver encounters a slow-moving vehicle, they will receive an alert that allows them to adjust their driving habits in order to avoid a rear-end collision.
Additionally, if a driver is experiencing a prolonged delay, they can use the information to make an informed decision about alternate routes. Using live travel times, the system will update variable message signs with comparative alternate route times.
A queue warning system can also monitor the speed of vehicles as they enter a work zone, providing a driver with time to slow down or avoid a rash braking behavior. Studies show that this approach can significantly reduce fatal crashes by up to 45%.
Several state DOTs are adopting this technology, ranging from Iowa to Illinois and Wisconsin to Michigan. It’s an easy and effective way to minimize travel delays, enhance motorist and worker safety, maintain access to local businesses and residences, and complete roadwork on time.
Alternate Routes
A Smart Work Zone uses Intelligent Transportation Systems (ITS) elements to ease congestion and increase safety as vehicles enter and travel through key highway construction projects. These technologies help drivers understand the work zone, identify lane closures and plan an alternative route before entering the area.
Drivers are often frustrated when they are trapped in a freeway work zone, which can result in long backups and other frustrating issues. Alternate routes are typically used as a way to bypass the construction or avoid a full road closure. These routes can be designed to run along the main highway and then connect up with it again but can also be designed to begin at another point and then link up with a main highway.
When motorists are trapped in a traffic jam, they usually do not know if there is an alternate route available that will take them to their destination, which can lead to frustration and a higher risk of rear-end collisions. This problem is solved by providing alternate route travel times, which give motorists an idea of how long it would take to get to their destination via the alternative route.
These alternate route travel times can be displayed on variable message signs, which are updated in real-time to show the comparative alternate route travel time. This helps travelers understand the magnitude of the delay and if it is worth it to use an alternate route.
Many of these systems can also be incorporated into queue management setups that tell drivers to slow down or merge early when they approach a lane closure. Other options are dynamic lane merges that tell drivers to merge early or right before the lane closure based on traffic speed.
ADOT is working with other agencies to implement these work zone smart solutions in the Phoenix area. These agencies are part of AZTech, a regional traffic management partnership.
To develop these strategies, TranSystems assembles design teams with experience in operations, engineering and construction. These experts can anticipate and address challenges and issues before they arise and can develop strategies to reduce user delays and improve safety.