The risk-based approach to TTM and some innovations have helped repair the road to Tairāwhiti after the 2023 North Island Weather Events caused slips, damaged bridges and culverts and significant damage to road surfaces and pavements.
With the events taking place between mid-January and mid-February, it was autumn before the Response Phase was completed, and next steps could be considered. The pavement condition on State Highway 2 between Ōpōtiki and Gisborne was identified as a significant risk over winter, with a need to quickly improve it to ensure goods could still be transported in and out of Tairāwhiti.
Many options were considered, with the best solution being Foam Bitumen Stabilisation (FBS) rehabilitation treatments. Quick to build compared to standard pavements, and with less sensitivity to moisture under ideal conditions, this treatment provided the solution required while not having the drawbacks of other options.
Options to complete this work were considered using NZTA’s risk-based guidelines to TTM.
3 weeks after the project team was established, work at the first site started.
Winter weather was an issue, so to improve efficiency the team moved to different parts of the network to maintain productivity.
Pilot vehicles were used to manage vehicle speeds past the worksite. Removing the number of people working on foot around moving plant or near traffic was key and reducing setup and pack-down time required.
The pilot vehicles allowed vehicle speeds to be managed dynamically, keeping people moving over newly constructed or sealed sections to minimise the risk of flushing.
