In-vehicle lane-departure warning systems can help reduce the risk of dangerous run-off-the-road crashes, according to a new study from researchers at the University of Minnesota’s HumanFIRST Laboratory.
“Run-off-the-road crashes are a huge concern, especially in rural areas,” says project co-investigator Jennifer Cooper, a HumanFIRST Lab assistant scientist. “Crash statistics tell us they contribute to more than half of all vehicle fatalities nationwide and that these crashes occur most often on two-lane rural highways.”
The toll of run-off-the-road crashes has made reducing these fatalities a top priority for transportation safety practitioners and researchers. One common countermeasure is shoulder rumble strips, but they come with drawbacks including startling drivers into overcorrection, generating noise complaints from neighbours, and creating a danger for cyclists.
“An alternative solution to rumble strips is in-vehicle lane-departure warning systems that can track the vehicle’s position in relation to the lane boundary and issue a timely warning,” Cooper says. “Currently, in-vehicle warning systems are in the early stages of development and have little consistency in the types of interfaces they use, making it the ideal time to study exactly how these systems impact driver behaviour.”
To aid in the development of appropriate and timely warning systems, HumanFIRST researchers studied behavioural responses to in-vehicle lane-departure warning systems using a driving simulator. In the study, participants drove two simulated real-world, two-lane rural highways with a history of lane-departure crashes.
During their drives, participants experienced simulated wind gusts that pushed their vehicle out of the lane. On half the drives, the in-vehicle warning system was active, causing the seat to vibrate and warn the driver when the vehicle was travelling out of the lane; on the other half of drives, the system was inactive. The severity of the run-off-the-road event was measured by how long the driver was out of the lane and how far they travelled out of the lane. The study also looked at the effects of variation in the reliability of the warning system, the impacts of driver distraction, and whether the system causes drivers to become dependent on the lane-departure warnings.
Results reveal that the lane-departure warning system is effective, Cooper says. Researchers found that the time drivers spent outside their lane when no system was active was significantly longer than when it was active. One of the biggest predictors of how much time drivers would spend outside their lane was speed, suggesting that if drivers slow down, they can return to their lane more quickly if they unexpectedly exit the lane. Researchers also discovered that distracted driving posed significant risks.
“Drivers who actively engaged in a distraction task were more likely to travel greater distances when they unexpectedly leave their lane, which could put them at a greater risk of striking a bicyclist, highway worker, or roadside infrastructure,” Cooper says.
The study results did not show any indication that drivers became dependent or over-reliant on the warning system. In fact, when drivers drove without the lane-departure warning system after repeated exposure to it, they maintained significantly reduced time out of lane and distance out of lane—suggesting use of this lane-departure warning system may have significant long-term benefits.
“Run-off-the-road crashes are a huge concern, especially in rural areas,” says project co-investigator Jennifer Cooper, a HumanFIRST Lab assistant scientist. “Crash statistics tell us they contribute to more than half of all vehicle fatalities nationwide and that these crashes occur most often on two-lane rural highways.”
The toll of run-off-the-road crashes has made reducing these fatalities a top priority for transportation safety practitioners and researchers. One common countermeasure is shoulder rumble strips, but they come with drawbacks including startling drivers into overcorrection, generating noise complaints from neighbours, and creating a danger for cyclists.
“An alternative solution to rumble strips is in-vehicle lane-departure warning systems that can track the vehicle’s position in relation to the lane boundary and issue a timely warning,” Cooper says. “Currently, in-vehicle warning systems are in the early stages of development and have little consistency in the types of interfaces they use, making it the ideal time to study exactly how these systems impact driver behaviour.”
To aid in the development of appropriate and timely warning systems, HumanFIRST researchers studied behavioural responses to in-vehicle lane-departure warning systems using a driving simulator. In the study, participants drove two simulated real-world, two-lane rural highways with a history of lane-departure crashes.
During their drives, participants experienced simulated wind gusts that pushed their vehicle out of the lane. On half the drives, the in-vehicle warning system was active, causing the seat to vibrate and warn the driver when the vehicle was travelling out of the lane; on the other half of drives, the system was inactive. The severity of the run-off-the-road event was measured by how long the driver was out of the lane and how far they travelled out of the lane. The study also looked at the effects of variation in the reliability of the warning system, the impacts of driver distraction, and whether the system causes drivers to become dependent on the lane-departure warnings.
Results reveal that the lane-departure warning system is effective, Cooper says. Researchers found that the time drivers spent outside their lane when no system was active was significantly longer than when it was active. One of the biggest predictors of how much time drivers would spend outside their lane was speed, suggesting that if drivers slow down, they can return to their lane more quickly if they unexpectedly exit the lane. Researchers also discovered that distracted driving posed significant risks.
“Drivers who actively engaged in a distraction task were more likely to travel greater distances when they unexpectedly leave their lane, which could put them at a greater risk of striking a bicyclist, highway worker, or roadside infrastructure,” Cooper says.
The study results did not show any indication that drivers became dependent or over-reliant on the warning system. In fact, when drivers drove without the lane-departure warning system after repeated exposure to it, they maintained significantly reduced time out of lane and distance out of lane—suggesting use of this lane-departure warning system may have significant long-term benefits.
