Police were called to the crash on State Highway 76 about 11am on Friday.
Motorists heading towards the Lyttelton Tunnel were forced to take a detour while the truck blocked the eastbound lane at the SH76 overpass.
The road was fully reopened at about 1.40pm.
There were no reports of injuries, a spokesperson said.
The truck was stuck under the bridge near Laing Cres.