One person was taken to hospital with what are described as “life threatening injuries” after witnesses after a collision in New Cheltenham Road, Kingswood.
Police said it happened in the early hours of December 13 and involved a grey Volkswagen Golf and several parked cars.
The road was closed in both directions while an investigation was carried out.
Police ask anyone who was in the area at the time of the collision, or has any dashcam footage thatcould aid their enquiries to get in touch.
Illegal cigarettes and vapes seized
POLICE and trading standards officers seized more than 35,000 illegal cigarettes worth an estimated £30,000 in a raid on a Staple Hill shop.
The operation at the K1 convenience store in the High Street, also uncovered 4.35kg of illegal tobacco and 192 single-use vapes, which were outlawed in June.
Two cars were also seized in the operation, which involved sniffer dogs and HM Revenue and Customs officers.
A police spokesperson said fire safety issues discovered during the operation in late October were also discovered and referred to Avon Fire & Rescue Service.
A council spokesperson said: “If anyone has information about the sale or supply of these products, please report it to Trading Standards via the Citizens Advice consumer helpline on 0808 223 1133.”