The Wairoa River Reserve road under the Wairoa Bridge will be closed to all traffic this Wednesday.

The closure will be from 9am until 3pm.

"The through-road will be closed from Te Puna Station Road through to the boat ramp on Wairoa Road for the construction of a speed hump as part of the cycleway extension work across the bridge," says a Western Bay of Plenty District Council spokesperson.

"Motorists are asked to take special care when exiting from Wairoa Road onto State Highway 2 during the reserve road closure."

The cycleway extension is one of the final stages of the Omokoroa to Tauranga Cycleway.

Waka Kotahi NZ Transport Agency advises motorists that the bridge will be closed today from 9.30pm to 5.30am.

'This is a significant closure and we encourage people to plan ahead, allow extra time, or consider delaying unnecessary travel where possible," says NZTA Bay of Plenty system manager Rob Campbell.

During the full closure the following local road detour will be in place:

• Northbound motorists from Tauranga will need to take the signposted detour from SH2 in Bethlehem via Moffat Road and Cambridge Road, onto SH29 before connecting with Poripori Road, onto Crawford Road through to Wairoa Road and then back onto SH2.

• Southbound motorists will need to take Wairoa Road before connecting with Crawford Road, through to Poripori Road and then onto SH29.

The detour route is not suitable for High Productivity Motor Vehicles (HPMV's greater than 50Max), over-dimension and overweight vehicles, says NZTA.