Two passing lanes with safety issues to get the chop between Cambridge and Piarere

An additional 1.6km of flexible median barriers like this are being installed on SH1 between Cambridge and Piarere. Photo / Duncan Brown

It will be a busy few weeks on SH1 between Cambridge and Piarere as significant safety improvements are installed near Maungatautari Rd.

Waka Kotahi NZ Transport Agency said from Tuesday, April 19 safety improvement work will run alongside road maintenance activity. Getting the work done concurrently will reduce the disruption to road users.

When completed, there will be some noticeable changes to road layout.

From April 19 to 21 the road will be under stop/go traffic management with associated lane closures in place overnight between 9pm and 6am.

The road will then be closed from April 26 to 28 between the hours of 9am and 3pm from, with a detour via Karapiro Rd, Taotaoroa Rd and SH29. All work is subject to weather and resource availability, the agency says

Surfacing work will see the final layer placed on top of the road rebuild undertaken last year.

A route map of SHI which would extend the expressway to Piarere. However, funding will not be applied for before the 2027-30 National Land Transport Plan period. Image / Supplied

"We have given the road 12 months to settle and compact and can now apply the asphalt surface with confidence it will hold up to the high volumes of traffic that use this road. Tree-felling will also take place to remove trees that pose a risk to road users should they fall," Waka Kotahi says.

At the same time there will also be changes made to the road layout to improve safety and 1.6km of median barriers will be installed. This is the next phase of an additional 5.4km of median barriers planned for this section of highway, from the current barriers south.

Flexible median barriers are recognised as the most effective solution for separating traffic and preventing head-on crashes on narrow roads, the agency says.

The 2.5km of median barrier installed in December 2020 has already more than proven its worth. It's been hit 40 times since installation - that's 40 incidents which could have resulted in serious head-on crashes.

The current give way sign at Maungatautari Rd will be changing to a stop sign. In addition to new road markings and the installation of 1.6km of flexible median barriers, there will also be a change to the passing lane and additional right hand turn bays put in.

The northbound passing lane will be taken out allowing enough room for emergency vehicles, maintenance activities and over-dimensional vehicles where the flexible median barrier will be installed.

This passing lane terminates very close to Kentucky Rd and Moana Roa Rd as well as some private and business entrances. There are unsafe manoeuvres at the end of this passing lane as slower drivers are often travelling close to the speed limit, so people overtaking using the passing lane travel significantly faster to overtake and then face issues merging back to one lane.

There are also future plans to take out the short southbound passing lane up the hill south of Maungatautari Rd when NZTA installs more median barriers in this area.

It says vehicles accelerating to pass here often find themselves braking hard at the top of the hill when they encounter slower traffic negotiating the SH1/29 intersection. This will become even more of an issue when construction of the SH1/29 roundabout begins (currently planned for the end of 2022), and traffic management will be in place.

Waka Kotahi says: "These changes support our Road to Zero vision. Keeping people safe through the use of median barriers is more important than keeping two passing lanes with identified safety issues. Data shows the passing lanes provide no travel time benefit (annual weekday) and at peak times actually cause lower speeds (Easter 2021 traffic).

"We are also finalising designs for the 7.5km of road from the end of the Waikato Expressway through to Fergusson Gully Rd. This is complex due to many intersections, accessways and properties. Safety improvements being considered include further flexible median barriers, roundabouts, rumble strips and intersection speed zones.

"The priority is reducing the risk of head-on crashes and improving intersection safety, including at SH1 / Karapiro Rd."

Waka Kotahi is working on longer term plans to extend the expressway to Piarere, however construction will be subject to funding availability and currently funding will not be applied for before the 2027-30 National Land Transport Plan period.

For more information on NZTA's long term projects in the area see: www.nzta.govt.nz/projects/cambridge-to-piarere/