Police are trying to trace two men who were in a car that smashed head on into another car and caused it to flip over, seriously injuring the driver.
The pair then fled in a light-coloured Vauxhall Astra – thought to have been travelling in convoy with them – before police arrived.
They had been in a silver Alfa Romeo in Maylands Avenue, Hemel Hempstead, when it veered across the road without warning and collided with a silver Mercedes A-Class at around 10pm on Tuesday, March 18.
The driver of the Mercedes – a 55-year-old woman from Watford – was rushed to hospital after the smash, near Duxons Turn.
Police have only just put out a public appeal for people with information about what happened to come forward.
PC Chris Payne said: “Firstly I would appeal to the driver and passenger of the Alfa Romeo to contact police to ensure we can gain their account of what happened.”
They are described as young white males who were both wearing tracksuits. PC Payne also appealed for the driver and any passengers in the Astra to contact him.
He said: “I would also like to hear from anyone who saw the two vehicles prior to the collision.
“My final appeal is to anyone who stopped at the scene to assist who hasn’t already spoken with officers to please call me.”
You can contact him with information about the smash by phoning the Herts police non-emergency number 101.