Improving work-zone safety with connected vehicles
Hundreds of motorists and highway workers are killed in work zones every year, and many more are seriously injured. Though the number of work-zone deaths has been declining in recent years, more than 600 motorists and 100 workers died in work-zone crashes in 2012—the last year for which fatality data is available.
“Though we have seen a decline in work-zone fatalities, even one death is too many,” said Imran Hayee, a professor of electrical engineering at the University of Minnesota Duluth and Roadway Safety Institute researcher. “We believe there is an opportunity to use connected vehicle technology to help achieve the goal of zero deaths.”
In recent years, the U.S. Department of Transportation has made the development of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication a major research priority. At a Roadway Safety Institute seminar, Hayee described how his research team has been working to develop a variety of uses for this new technology, including a series of recent projects focused on work-zone safety.
“In the work-zone environment we know that one or two lanes are typically closed, resulting in congestion and increased travel times,” Hayee said. “However, the start of the congestion is variable, and by warning drivers in advance about the exact location of congestion and providing travel time information, we can help improve safety.”
In the initial project, funded by the ITS Institute at the University of Minnesota, Hayee’s team developed a portable roadside unit to use as a V2I traffic information system. The unit uses Dedicated Short-Range Communication (DSRC) to monitor a selected vehicle’s progress through the work zone, then transmits the information it collects at the start of congestion and travel time to all other vehicles equipped with connected vehicle technology in the area. The portable unit proved effective in field tests but had a limited range. Hayee wanted a way to extend it to a more typical work-zone length of several miles.
To that end, the team developed a V2V-assisted V2I system. “With this system, instead of using the portable unit to track the vehicle through the entire length of the work zone, we use the vehicles in the work zone equipped with smart vehicle technology to ‘hop’ the message back to the portable unit,” Hayee explained. “This way, we can cover a work zone of two to five miles and communicate messages to vehicles more than five miles away from the start of the congestion, giving drivers time to seek an alternative route.”
It will be many years before all vehicles are equipped with V2V communication capabilities, so the next challenge was creating a way to disseminate this information to all motorists. To accomplish this, Hayee’s team designed a smart portable message sign that can pick up delay and travel time information from connected vehicles and display it along the roadside.
Hayee’s current research, sponsored by the Minnesota Department of Transportation, focuses on developing a system that will collect and disseminate work-zone congestion and travel time information solely through V2V communication and eliminate the need for a portable roadside unit. In addition, road geography data are being incorporated into these systems to ensure the information is communicated only to vehicles traveling on the road affected by the work zone.
Though these technologies may seem futuristic, Hayee’s research shows they may not be far off. “We found that during rush hour, just 20 percent of vehicles would need to be equipped with vehicle-to-vehicle communication capabilities to make these systems work,” he said.