Like human drivers, autonomous vehicles sometimes have trouble "seeing" in some low-visibility situations and adapting quickly to loss of traction.
To date, many of the self-driving cars being tested have experienced difficulty in this area. Often, their sensors can be blocked by snow, ice or torrential downpours, and their ability to "read" road signs and markings can be impaired if they're covered by snow.
At the 2016 Detroit Auto Show, Ford announced that it is working with the University of Michigan to develop a solution based on high-resolution 3-D digital maps that include data about road markings, signs, geography, topography and landmarks. With this more detailed information, Ford says its autonomous Fusion Hybrid sedans are able to navigate effectively in poor weather conditions.
"It's one thing for a car to drive itself in perfect weather. It's quite another to do the same thing when its sensors cannot sense the road through snow, or when visibility is limited by falling precipitation," explained Jim McBride, Ford's technical leader for autonomous vehicles, in a statement. "In Ford's home state of Michigan, we know weather isn't always perfect. That's why we're conducting testing — for the roughly 70 percent of U.S. residents who live in snowy regions."
Ford says it's been conducting tests of the new technology at Mcity, the university's 32-acre simulated urban environment, with good results.
Meanwhile, amid a multi-year drought in California, Google's self-driving vehicles have now been confronted with a significant amount of rain in the area around their Mountain View test area.
As Google says in its latest Self-Driving Car Monthly Report: "Driving in rain makes many human drivers nervous due to reduced visibility, and some of our sensors — particularly the cameras and lasers — have to deal with similar issues."
The various types of sensors and cameras may not actually get nervous, but some do experience reduced effectiveness when they become blocked by heavy rain, fog and clouds of exhaust from other vehicles.
To help address the problem, Google has equipped the sensor domes on top of its self-driving cars — Lexus RX 450h SUVs and its own prototypes — with little windshield wipers. These, says the tech company, "ensure our sensors have the best view possible."
In addition, says Google, the recent rain has allowed their cars to "learn" more about driving under low-visibility and low-traction conditions: "Our cars can determine the severity of the rain, and just like human drivers they drive more cautiously in wet conditions when roads are slippery and visibility is poor."
Google also notes that if conditions become too hazardous, its cars will automatically pull over and wait until it's safe to proceed.
Concludes Google: "To explore even more challenging environments, we're beginning to collect data in all sorts of rainy and snowy conditions as we work toward the goal of a self-driving car that will be able to drive come rain, hail, snow or shine!"
Edmunds says: As self-driving technology advances, it's critical that autonomous vehicles demonstrate the ability to handle a variety of road and weather conditions.