A man has been arrested on suspicion of dangerous driving after a collision left a woman in 'critical condition' at hospital.
Police are appealing for witnesses and information following the collision on Wednesday (May 24)
Officers were called just after 10pm to reports that a black BMW M6 had left the roundabout at the junction of St Agnells Lane and Redbourn Road, mounted the kerb and collided with a female pedestrian and a stationary vehicle.
The woman was taken to Watford General where she remains in a critical condition, while the road was closed until just before 1am on May 25 to allow investigations to take place at the scene.
Police have confirmed that the person arrested on suspicion of dangerous driving is a man in his 30s.
Anyone who has not already spoken with police and who saw what happened or saw the car, which was a hire car, prior to the collision is asked to contact the Herts Police non-emergency number 101 quoting reference 918.