

https://www.scoop.co.nz/stories/AK2511/S00122/overnight-full-closures-on-koheroa-road-overbridge-at-mercer.htm

Overnight Full Closures On Koheroa Road Overbridge At Mercer

Thursday, 6 November 2025, 1:07 pm
Press Release: NZ Transport Agency

Maintenance is scheduled for State Highway 1 Koheroa Road overbridge (local road) at Mercer, which will mean closures and detours from Sunday 16 to Tuesday 18 November between 9pm and 5am.

There will be full closures in both directions between Mercer Ferry Road and Hall Road, including Koheroa Road overbridge over the three nights.

During this time the team will remove the asphalt and carry out maintenance on the bridge joint. Once work is complete, the asphalt will be reinstated.

All on- and off-ramps at Mercer will remain open but traffic will not be able to travel across the overbridge.

To travel to and from the township please follow the recommended detours:

To travel eastbound across Koheroa Road overbridge (away from the township), use SH1 Mercer northbound on-ramp and turn around at Pioneer Road southbound on-ramp to travel south. You can exit at Mercer to access the township (travel time 7 mins).
To travel westbound across Koheroa Road overbridge (towards the township), take SH1 Mercer southbound on-ramp and please travel south on SH1 and turn around at Hampton Downs. You can exit at Mercer to access Koheroa Road (travel time 13 mins).

Setting up the detour and signs will start at least one hour before the advertised closure time.

This work is weather dependent and may be carried out on Wednesday 19 and Thursday 20 November if required. Please check the NZTA Journey Planner for real-time closure information before travelling.

Surrounding properties may experience increased noise from machinery and vehicles.

We appreciate the closure of the overbridge will impact the community and would like to thank you in advance for your patience and support as we carry out this important maintenance.

If you have any questions, please email www.nzta.govt.nz/asm.

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