A large truck rolled on State Highway 2, near Pukehina, earlier this morning, blocking both lanes of traffic.
Traffic diversions are in place around the crash 2km east of Pukehina and police said the truck was leaking fuel.
The driver was unharmed and emergency services were in attendance.
Traffic has been diverted while the trucks is being removed and the discharged fuel cleared from the road.
Removal and clean-up was expected to take at least a few hours, as a heavy lift crane was needed to remove the truck.
Motorists travelling east can detour the crash by turning off SH 2 at Pukehina Station Road before travelling to Old Coach Road and then returning back on to the State Highway.
West bound traffic are advised to use the same route, leaving SH2 at Old Coach Road before turning onto Pukehina Station Road and rejoining SH2 west of the crash site.