The 911 button on modern vehicles can come in handy during emergency situations, even when those in the vehicle have cellphones.
A story posted on the Fremont Motors blog recently details a trip off the beaten path near Casper, Wyoming. Steep travel and failing brakes resulted in a wheel coming completely off a truck in an area far from paved roads. Cellphone service was non-existent at the time, but a 911 button near the truck's rearview mirror still connected with emergency service.
Once connected with emergency service, the 911 representative may be able to track your vehicle by GPS, as was the case of the Fremont Motors story's author.
Accessing 911 through a vehicle happens differently depending upon make and model. On General Motors vehicles, 911 is accessed through OnStar buttons. On Ford vehicles, 911 Assist is accessed through the SYNC system. Others offer it through UConnect, whether the service is labeled as assist, 911 or SOS.