First the concern was texting and driving; now it's Pokémon Go.

As the popular app has skyrocketed in the last few days, authorities are now worried people may be playing at inappropriate times.

Multiple traffic signs on highways in Dane County, Wis., and in Milwaukee now read "Drive Now. Catch Pokémon Later."

The Pokémon Go app, developed by Niantic Labs, uses the phone's GPS and camera to allow users to capture Pokémon characters in real locations, such as walking down a sidewalk — or worse, driving down the street.