Waymo’s next stop for its self-driving Chrysler Pacifica test vehicles is Michigan. The company that sprung from Google’s self-driving car project will be deploying its autonomous cars just in time for Michigan’s winter, too, which will mean that they should encounter a range of major challenges, including snow, sleet and frozen roads.

This isn’t the first time Waymo has brought its vehicles to snowy conditions: It’s done some testing near Lake Tahoe to see how its cars would perform in more wintery environs,. But putting some of its Pacifica fleet to the test in Michigan is a different story, and will involve likely more rigorous and consistent testing.

Waymo previously opened a dedicated development center for its self-driving tech in Novi, Michigan, but this makes the first time it’ll be testing its vehicles in the state on pubic roads, and builds on its existing work there to develop tech along with partners.

The testing will begin in the Greater Detroit area, starting with Novi, in the next few weeks, and all vehicles will have trained safety drivers on board like the rest of Waymo’s testing fleet.

Winter testing is not new for Waymo, which has been running trials in cold conditions since 2012, but having a fleet in operation in dedicated winter conditions in Michigan will be a huge boon to its ability to ensure its tech is not only ready to deliver autonomy on winter roads, but also to make sure its tech stack and hardware are ready to last over time in harsher conditions.