Four people are currently being treated for life-changing injuries following a collision.
Officers are appealing for information after the incident on the A6 near Knotting Green on Sunday (July 31).
At around 3.50pm, emergency services were called to a two-vehicle collision involving a grey Volvo XC40 and a green Plymouth GTX.
More than 400 potential victims of modern slavery identified in Bedfordshire last year
Bedford bus company revises timetable after passenger numbers review
Bodycam footage shows police breaking into hot car to free distressed dog stuck in high temperatures
Three members of the same Bedford family die in Italian road crash
Bedford woman jailed after head-on collision on wrong side of the road
The Plymouth GTX – which is believed to have attended an American Muscle Cars event at Santa Pod – was traveling southbound on the A6 when it collided with the Volvo, which had joined the carriageway at the junction with Knotting Green.
Two occupants in each vehicle were taken to hospital, where they remain.
Sergeant Chris Payne, from the Bedfordshire, Cambridgeshire, and Hertfordshire Roads Policing Unit, said: “We are appealing to anyone who witnessed the collision to contact us as soon as possible to determine the facts surrounding this incident.
“If you were in the area and have any dashcam footage of the incident or leading up to the incident, please get in touch.”
If you have any information that could help, call police on 101 or report it online and quote Operation Sparkle.