Traffic signals trial for Maruia River Bridge, Picton to Christchurch state highway route


Traffic signals are being trialled on the Maruia River Bridge on State Highway 65 just north of Springs Junction. The signals will start working either later today or first thing tomorrow, January 27, once all the road markings are in place.

“The signals will assist drivers by managing traffic flows across the single lane bridge,” says Transport Agency Highway Manager Frank Porter. “The bridge is one of 15 single lane bridges on the alternate Picton to Christchurch State Highway route and signals will make it very clear who has the right of way. The bridge also has poor sight distance when approaching from the north.”

Photo taken in recent days before all the road markings were in place

Photo taken in recent days before all the road markings were in place.

The length of the bridge and the challenges for drivers to see oncoming traffic made it a good candidate for the trial, says Mr Porter.

“One-lane bridges rely on priority control and drivers following the give way rule. The approach curves for this bridge in particular have a relatively narrow lane width and the give way limit lines are close to the bridge to maximise visibility. This can make it difficult for vehicles driving off the bridge, particularly trucks, when an opposing vehicle has overshot the give-way limit. Trucks often track off the edge of the seal to allow opposing trucks enough space to exit the bridge.”

While drivers have been managing to cross the bridge safely since the November 14 earthquake, with the alternate route now the main highway between Picton and Christchurch, these traffic signals will improve safety and assist traffic flow. They will allow the limit line to be pulled back, away from the bridge slightly, giving vehicles more manoeuvring space.

The traffic signals operate and will be monitored 24/7 by the Transport Agency’s Wellington Transport Operations Centre and include state of the art sensors which send real time information on traffic crossing the bridge.As well as the sensors, Transport Agency staff and their specialist traffic signals contractors can see what is happening at the bridge through a camera.

Traffic camera views of the bridge

Traffic camera views of the bridge

“The detector loops and radar monitoring equipment will extend the lights phase if vehicles are still on the bridge, keeping everyone safe,” says Mr Porter.

“The traffic signals are part of a suite of safety improvements on the Christchurch to Picton alternate route to deal with the increase in traffic volumes, particularly trucks.We will monitor their performance over the coming months, particularly as we head into the darker winter months when weather and reduced light can make driving more challenging.”

Extra information

The Transport Agency’s Crash Analysis System database (CAS) identifies six crashes at this site in the latest 10 year period.One of these resulted in serious injury and one in minor injuries. The remaining four were non-injury.

Why lights at this particular location?

The traffic signals at this site were part of a suite of safety measures proposed on the alternate state highway route given the additional traffic and substantial increase in heavy freight volumes.

What is the traffic count at this location?

In 2015, around 1,000 vehicles per day.

December 2016 traffic increased up to 2,500 vehicles per day. The busiest day of the 2016/17 holiday period was 27 December with 6,000 vehicles through Lewis Pass, compared to 3,200 vehicles on 27 December 2015 (the busiest day of the 2015/16 holiday period).

How long will the TransportAgency trial the signals for?

Ongoing – The Transport Agency will monitor traffic volumes and safety.

How much is this work costing?