Officers were called out to the Bradford-bound carriageway of Stanningley Bypass near to Richardshaw Lane shortly before 7pm.
A white Skoda Yeti was involved in a collision with the back of a white DAF tipper truck that was stationary in lane one, having broken down, police said.
They added that the male driver of the Yeti, who was the sole occupant of the vehicle, has been seriously injured.
The driver of the truck was not in his vehicle at the time and was not injured, West Yorkshire Police added.
The Bradford-bound carriageway is closed and a diversion is in place. The closure is expected to remain for several hours and drivers are advised to avoid the area.
Officers are keen to hear from anyone who witnessed the incident or the circumstances leading up to it, particularly anyone who was driving in the area and had dashcam footage showing the collision itself or either vehicle prior to it.
Anyone with any information is asked to contact the Major Collision Enquiry Team via 101 quoting log number 1581 of November 24.