How Well do Automated Vehicles Perform When the Weather Doesn't Cooperate?

Technology is advancing rapidly and differing levels of driving automation are in various stages of development. Some of us already are using automated vehicles (driverless vehicles). But how do these vehicles perform when the weather isn’t sunny? 

Battelle is working with the Federal Highway Administration to learn how weather affects automated vehicles. 

Slippery pavement, difficulty seeing the road, and other vehicles take a toll on human drivers. Weather figures in 22 percent of ordinary vehicle crashes. The Federal Highway Administration is working in several ways to enable a safe deployment of automated vehicles and ensuring safety in all weather is an important part of that.

Automated vehicles have different  sensors to detect what’s happening around them. Many cars today have a radar that looks ahead and keeps you from driving into a slower car if you are distracted and when your cruise control is set. Some cars also use radar to assist in maintaining following distance in heavy, crawling traffic. Most cars on the market also have video cameras on the windshield that can see the yellow and white pavement stripes and help keep the vehicle in the lane. Different manufacturers use additional sensors and different capabilities in their products.

Battelle ran tests with three 2016-2018 model vehicles at the Transportation Research Center Inc. in Ohio. We tested automated driving capabilities in different weather conditions. We drove automated vehicles through falling rain and light snow. We coated the sensors with ice. We checked what happens when the camera is pointed at the glare of a rising or setting sun. 

Automated vehicle manufacturers remind drivers that it’s important to pay attention to what the car is doing at all times, and we found that’s good advice. Not surprisingly, all vehicles had difficulty with ice-covered sensors. But, far less adverse conditions also presented challenges. Video cameras could see lane stripes when they were wet, but lightly blown snow made the stripes hard to see. Automated Vehicles generally performed well at lane keeping and in simulated traffic jams even in the rain, but heavy rain could briefly confuse following capabilities at highway speed.

Battelle hosted a workshop of state transportation officials in January to hear their thoughts on research needs for highway design and policies. 

In July, Battelle will lead a workshop at the Automated Vehicles Symposium in San Francisco to share results from our work so far and to gather input from researchers and vehicle manufacturers.

About the Authors
Senior Research Scientists Doug Pape and Dave Neumeister are working on smart infrastructure solutions at Battelle.