A driver of a truck that rolled over an intersection near Ashburton has escaped injuries.
A police media spokesperson says the crash happened on State Highway 1 Tinwald, at the intersection of Hendersons Road.
"The crash happened just before 5.30am.The driver is uninjured and no other vehicle has been involved.
"The truck is clear of the railway lines, however the road is completely blocked.
"There are diversions in place and motorists are asked to observe these diversions while the road is being cleared and this could take some time.