Concern for Tas crash driver

Police are worried about a driver who fled a serious car crash in northern Tasmania, leaving a crumpled wreck beside a highway.

Just after 4am on Monday a Holden Astra veered off the East Tamar Highway at Launceston, rolling onto its roof as it swiped fencing before the driver made tracks.

"Police hold grave concerns for the driver and are seeking any information from members of the public who may have witnessed the accident or can assist police in locating the driver whose injuries are unknown," Sergeant Scott Mackenzie said.