Police are at the scene of an incident in Hemel Hempstead this morning.
Both ends of Figtree Hill near the town’s fire station have been cordoned off.
An ambulance arrived on the scene and a person was treated by the crew in the road before being taken to hospital.
An older style Land Rover remains in the road as police officers carry out an investigation.
Paramedics were called at 7.47am on September 7 to reports of a person who was unconscious in Queensway, Hemel Hempstead.
Hertfordshire Police confirm an elderly man had suffered a medical episode in the street and was subsequently involved in a collision with a vehicle.
He was taken to Watford General Hospital for treatment where he was deemed to have suffered serious injuries.
The road closure was lifted at 9.35am.