Watch CBS News

Good Question: 'Reply All' Dirty Rain & Smart Phone Traffic

MINNEAPOLIS (WCCO) – We've had a fair amount of rain this spring, and it's making our cars look just filthy.

Ann in Melrose wondered: Why is some rain really dirty?

If it's dry and windy, the dirt gets thrown into the atmosphere. It's been very windy lately, so the dirt particles are hanging around. When rain starts to form, it forms around something like a grain of sand or a particle of dirt.

But when a bunch of dirt is kicked up into the atmosphere (like it was this week), the rain forms around those particles and falls onto our cars.

Michelle from Big Lake uses the navigation on her smart phone every day. But how does it know where the bad traffic is?

It's a combination of sources. Google Maps uses some third-party sources, like companies that track traffic data from the sensors in the highways.

But there's information on side streets, and a lot of the data comes from regular people driving around.

If you've turned on the "My Location" feature on Google Maps, Google can tell where you are. And if a bunch of people are moving slowly, Google's computers know and are able to tell you which spots are bad.

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.