A stretch of Horbury Road was shut for more than three hours after an elderly man was hit by a car.
Police have confirmed he was flown by air ambulance to Leeds General Infirmary and suffered serious injuries.
The collision, which occurred at around 11.55am, involved the man (a pedestrian), and a silver Ford car.
Emergency services were called to the scene to assist and enquiries into the incident are ongoing.
Motorists faced delays as police closed the road between the M1 motorway bridge at Lupset and the junction with Cumbrian Way.
It re-opened at around 3.15pm.