West Coast police today advised motorists to take extra care when driving through the Lewis Pass and Maruia Valley on State highways 7 and 65 as traffic numbers build up.
Greymouth prevention sergeant Paul Watson said road police patrols had been stepped through the area due to "a massive increase" in traffic, diverted via Blenheim and Murchison to Canterbury, as a result of the Kaikoura earthquake.
Other measures were being investigated to deal with the increased traffic flows, with more heavy trucks and freight movements through the Lewis to Christchurch.
"We are looking at working with NZTA to get some temporary speed restrictions in place ... because of the increased traffic flows," Mr Watson said.
The Maruia Valley School was one example where speed restriction measures would be taken.