Police are appealing for witnesses and information following a serious road traffic collision on the A1 Barnet Bypass near Borehamwood.
The collision occurred on the southbound carriageway shortly after 4.35pm on Saturday, April 9.
A silver Toyota Yaris was travelling along the carriageway when, for reasons unknown at this stage, it lost control and collided with the nearside barrier before coming to rest on the other side of it.
The driver, a woman aged in her 30s, sustained serious head injuries and was taken by air ambulance to a London Hospital where she remains in a critical condition.
PC Jackie Lister, who is investigating, said: “I am appealing for anyone who witnessed the collision, or events leading up to it, to please get in touch. I am particularly keen to hear from the drivers of two vehicles which the Toyota passed between as it left the carriageway.”
Anyone with information is asked to contact the Bedfordshire, Cambridgeshire and Hertfordshire Forensic Collision Investigation Unit on the non-emergency number 101, quoting ISR 485 of April 9.
Alternatively, you can contact the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111 or through their Anonymous Online Form at www.crimestoppers-uk.org. No personal details are taken, information cannot be traced or recorded and you will never need to go to court.