Keeping driverlesscars on the road in snow

Whenever the first snowfall of the year blankets Calgary, the Canadian city I grew up in, the roads swiftly become lined with cars that have spun out of their lanes. There’s a distinctly Canadian remark that comes along with spotting a car caught up in the annual mass fender-bender – “must be new” – based on the assumption that all the roadside wipe-outs are clearly recent arrivals to town. After all, anyone who’s lived locally for a year is forced the hard way to learn how to drive in snow, so anyone slip-sliding across the motorway must be a newbie.

There are many tricks to driving in snowy conditions, but here are a few: drive slowly, even slower than you think you should; if snow obscures the lane markings, follow the lights of the car ahead; when slipping on ice, braking can make it worse.

Teaching such lessons to a human driver is hard enough, so how do we ensure driverless cars can manage in inclement winter weather?

Most of the big automated vehicle test projects are run in warmer climates – largely California and Arizona – and weather has already proven a challenge, with reports suggesting Alphabet’s Waymo car struggled with intense rain, sparking a trial