Challenge

The earthquake that struck Kaikoura was the biggest earthquake in New Zealand’s history. The quake devastated the main transport arterial route through Kaikoura which links Picton and Christchurch, cutting off the small town and severely impacting the main freight transportation network in the region.

The New Zealand Transport Agency’s (NZTA) immediate requirement was to analyse and advise on a safe, alternate transport route as quickly as possible. Gordon Hart, from the NZTA and director at IDS (Infrastructure Decision Support – an industry-driven not-for-profit organisation), and his team were tasked with this challenge. They were given a two-day turnaround to assess what their options were for an alternate route for primarily freight vehicles, which at that stage was the State Highway 63 to State Highway 7 network.

They needed to know what additional surfacing and paving work might be needed on this alternative route in order to create a sustainable route for the medium term, with a time horizon, at that time for planning purposes, of up to three years. dTIMS is used in New Zealand and had recently been used to model the national network generating a 20-year forecast. This was used as a starting framework to assess the new route.

Solution

A key part of the project fell on Elke Beca from Opus, who carried out the modelling / theoretical work over two working days and one weekend. The team found the dTIMS tool was flexible enough for them to customise and add in extra functions, specifically the expected traffic loading increases.

This increased the sensitivity of the model, resulting in a model-generated work programme that aligned very well with the programme visually assessed by the team in the field based on people’s knowledge of the network. This gave the whole team confidence they were in the right ball park.

The reconnaissance work was carried out on the Thursday / Friday, while simultaneously, Elke was conducting the dTIMS modelling work. They drew on both the modelling tool and the team’s experience to help construct a plan of what additional programming and surfacing work was needed to create a sustainable route for the medium term.

Results

The NZTA team constructed a plan of what additional programming and surfacing work was needed to create a sustainable route for the medium term. The alternate route was established for the main freight network.