All three occupants of a car died in a 'horrific' crash when a vehicle driving the wrong way down a slip road smashed head on in to them.
One man was arrested on suspicion of causing death by dangerous driving and driving under the influence of alcohol or drugs after the Peterborough collision.
Police were called to the slip road to Stanground off Fletton Parkway at midnight yesterday.
The driver arrested is now in critical condition in hospital.
The chairwoman of the Cambridgeshire Police Federation, Liz Groom, said it was 'such sad news'.
'Thoughts with the families of those who have died,' she tweeted.
In a statement Cambridge Constabulary said: 'One vehicle had driven down the slip road the wrong way and collided head-on with another vehicle, killing all three of its occupants.
'Police were called to a collision involving two vehicles at the slip road to Stanground on the westbound carriageway.
'The driver of the offending vehicle has been arrested on suspicion of causing death by dangerous driving and driving while under the influence of drink and/or drugs.