A 17 year old learner driver has been seriously hurt in a collision with a Jeep.
The Jeep driver - a 48-year-old woman from Hurstpierpoint - was also seriously hurt, according to police.
Police say they were called shortly before 8pm to the A273 in Burgess Hill to a two vehicle collision.
A learner driver on a lesson, in a grey Vauxhall Astra, was travelling northbound when it crossed onto the opposite carriageway colliding with a silver Jeep Patriot travelling south.
A 17-year-old girl from Pyecombe driving the Vauxhall and the 48-year-old woman from Hurstpierpoint, who was driving the Jeep, were both taken to Royal Sussex County Hospital with serious injuries.
A 39-year-old man from Brighton, the passenger in the Vauxhall, suffered a minor injury.
Anyone who saw what happened is asked to contact police on 101 or email firstname.lastname@example.org quoting serial 1269 of 21/1.