The Transport Agency says initial repairs to state highways damaged in the Canterbury earthquake could cost up to $6 million.
Many highways suffered damage in the form of cracks and upheaval when the 7.1-magnitude quake hit on 4 September.
Approaches to most highway bridges have also dropped, in most cases by about 20 millimetres.
The agency's North Canterbury area manager, Barry Stratton, says a significant amount of repair work is being done by contractors, while a number of specialists are assessing roads and bridges.
Mr Stratton says some sections of road, particularly in areas where liquefaction occurred, are unlikely to be fixed completely until the ground underneath stops moving.
