Philadelphia has a clever new program to try to get drivers to slow down: optical illusion speed bumps!
The city is putting out high-tech plastic devices that create a 3-D image that looks like a bump in the road. Chief traffic engineer Charles Denny says in reality, the road is perfectly flat.
Denny says the goal is simple: to change the driver's mind-set to be less aggressive.
The devices will be deployed at about 100 intersections around Philadelphia. They'll give the illusion that something is sticking up out of the pavement so motorists will slow down.