Every year, severe wind on Wyoming's Interstate 80 blows almost a hundred commercial trucks off the road, while the highway's penchant for thick fog and snow storms contribute to thousands of accidents. Wyoming officials say the incidents cause around half a billion dollars in annual property damage.
Officials have imposed variable speed limits and closures to light vehicles during extremely severe winds to curb highway accidents. The state also requires all truck drivers to sign up for an online program that lets them share updates on road conditions from a tablet or smartphone, so that other drivers might know what to expect.
But later this year, Wyoming's transportation agency will convert I-80 into a testing ground for wireless systems that let vehicles talk to each other directly. State officials will retrofit around 400 snow plows, commercial trucks, and patrol cars with on-board units that can send weather updates and collision warnings to other nearby vehicles.
The highway is one of three locations that the Department of Transportation is using to test vehicle-to-vehicle communications, in which cars broadcast their location, speed, and other information so that other vehicles can warn drivers of potential hazards. The National Highway Transportation and Safety Administration says that V2V technology could reduce 80% of crashes that don’t involve alcohol or drugs.
The U.S. DoT is spending $4.4 million to bootstrap Wyoming project's on the 402-mile highway. It is also investing around $22 million in another pilot involving 8,000 New York City taxis and buses, as well as $16 million to test V2V communications on a reversible highway in downtown Tampa Bay, Fla.
But the Wyoming pilot is unique in that it will let cars chat about severe weather, using sensors on snow plows, trucks, and fleet vehicles to calculate local weather conditions. It also stands out for focusing on a major commercial trucking route instead of urban transportation: up to 8,000 freight vehicles from 45 states drive on the I-80 every day.
“This is not just a Wyoming issue,” said Ali Ragan, a project manager for the Wyoming Department of Transportation, at a recent South by Southwest panel in Austin, Texas. “This isn’t even a western United States issue. It really impacts drivers from all over the country.”
The pilot is an early test for safety technology based on dedicated short-range communications, which will be required for all new cars and light trucks by 2023 under a proposed federal rule. Cars equipped with DSRC technology send and receive standardized messages 10 times per second over a section of wireless spectrum reserved for automobiles.
Wyoming officials will install 75 roadside units along the highway to collect information from the 400 commercial trucks, snow plows, and other vehicles in the pilot. The project uses fewer vehicles than other pilots, but the technologies that officials are already using to improve safety give it a running start.
Officials have embraced a National Center for Atmospheric Research system that lets cars collect information from temperature sensors and windshield wipers and share it over cellular networks. The Pikalert system combines those data with measurements from satellites, weather stations, and specialized sensors on fleet vehicles to create weather reports that update every fifteen minutes.
The pilot cars in Wyoming will support safety features like forward collision warning and distress signals for emergency responders. When a truck’s airbag goes off, for example, the on-board unit will send a distress signal to a roadside unit. If none are close by, then the truck will throw the message to a passing truck, which will toss the message into the next roadside unit.
The pilot is not without its shortcomings. In their application, Wyoming officials worried that spreading only 75 road units over 402 miles of highway would make it difficult to learn anything useful. Because DSRC only works over 1,000 meters, officials are placing the roadside units in places where the most crashes happen, Ragan said.
Those shortcomings are why many wireless carriers and chip makers argue that 5G cellular networks will be better suited for V2V communications. When the final standard is finished, 5G could send message over longer distances and allow for more detailed data like video to be shared, they say.
On the other hand, DSRC is potentially faster than cellular networks because it allows cars to send messages and collision warnings directly, without having to route them through a cellular base station. Another potential advantage is that the hardware can be installed in rural areas with little cellular infrastructure.
But the cost still might be too high for states with shrinking budgets. From that perspective, much is riding on the success of the connected vehicle pilots, said Bob Frey, a project manager at the Tampa Hillsborough Expressway Authority pilot, who also participated in the SXSW panel.
“You have to convince agencies it’s worth spending money on,” he said.