Witnesses to a collision in Taunton, as well as motorists with dashcam footage, are being asked to contact police.
At approximately 3.35pm on Sunday 7 February, a black Ford Transit van and a red Audi collided at the junction of Great Western Way and Silk Mills Road.
The van driver left the scene without providing details.
A 30-year-old man has subsequently been arrested on suspicion of failing to stop. He has been released under investigation.
Anyone travelling along Silk Mills Road or Great Western Way at around the time of the incident, or has dashcam potentially showing the vehicles involved, is asked to call 101 and give reference 5221027239.