The A635 Barnsley Road at Scawsby has been closed in both directions with cordons sealing off the road near to Ridgewood School.
The road is closed from Emley Drive out of Doncaster and from Scawsby Lane towards the town centre.
According to eyewitnesses, the area has been the scene of heavy police activity since about 3.30am this morning.
Residents have reported a number of police, fire engines and ambulances at the scene.
Photos show scenes of crime investigators carrying out investigations close to the pedestrian crossing near to Ridgewood School.
The AA said: “Road closed due to accident on A635 Barnsley Road both ways from Ridgewood School to Rosedale Road. The road has been closed since Saturday morning.”
The closure was first reported just after 5am.
Motorists are advised to avoid the area.