A woman in her thirties was taken to hospital with serious injuries following a hit-and-run incident on Monday (September 24).
Police were called at 4.34pm to reports of a pedestrian and a vehicle involved in a collision in Adeyfield Road, Hemel Hempstead.
The vehicle, believed to be a burgundy/red Ford Focus or Mondeo, was not at the scene on police arrival.
Officers put road closures in place and these were lifted at around 6pm.
The ambulance service attended the pedestrian, who was taken to Watford Hospital.
Any witnesses, or anyone who has information about the collision, should contact Hertfordshire Constabulary on the non-emergency number 101, quoting ISR 542 of September 24.