Among the tall pine trees of Davy Crockett National Forest sits a stretch of road David Robison calls “the dead zone.”

There is no cellphone service for miles, and there are few signs of civilization on this remote section of highway. It lacks safety precautions like shoulders or guardrails that are ubiquitous on more urban highways.

So when Robison receives a dispatch from the sheriff’s office about a car wreck in the dead zone, he hops in his ambulance and prepares for a challenge…

Spotty cellphone coverage is just one obstacle Robison and other rural emergency service providers face when they respond to traffic accidents. And it’s one of the factors — along with high speeds and low seatbelt usage — that contribute to a stark disparity between rural and urban highway traffic fatalities.