DETROIT -- Imagine you could control traffic by turning a light from red to green from your car. A new device makes it possible.

We've all wanted to snap our fingers and turn stoplights green. This new device on the market may grant your wish but many believe it's a nightmare.

Just flip the switch and MIRT (which stands for mobile infrared transmitter) beams a signal, instantly changing traffic lights and giving rescue workers like the Washington Township Fire Department a straight shot to emergencies. Now the public's getting the green light to own similar devices thanks to Internet-marketed copycats.

With dozens of receivers set up in selected intersections across Macomb and Oakland counties, many fear it could cause chaos as motorists fight to control lights.

"You're talking about a lot of congestion and a lot of problems," Macomb County Sheriff Mark Hackel said.

Hackel believes the dashboard devices should only be used for larger rescue vehicles, not for the public or even police cars.

The device costs about $300, and right now it's legal because unlike certain radar detectors, it does not emit radio signals.