GTM 10, an FM TMC (Traffic Message Channel) traffic receiver, is a permanently installed device that connects with your car radio/antenna system (professional installation required). It receives digital information (where available) on traffic and road construction tie-ups and sends it to your compatible Garmin navigator to offer an alternate route. TMC data is available in a fast-growing number of cities throughout North America and Europe, and gives prompt, accurate notification of accidents, road construction, police or emergency action, etc. — so you can visually monitor traffic flow and, if necessary, avoid traffic tie-ups.