TDG was asked by NZTA to develop a microsimulation model of the Tauriko business park and its intersections with the Pyes Pa Bypass and SH29, at the southern end of Tauranga. The objective was to identify the effects of the proposed Tauriko Bypass, which will redirect SH29 around the village of Tauriko, on the slowly developing business park.

The outcome from our initial brief was that significant congestion was predicted as a result of the number of vehicles travelling between the proposed retail area of the development and the residential areas to the east. After presenting the results to the client, we were asked to further develop the model to include potential mitigation features, namely an additional roundabout on the state highway providing an alternative access to the retail zone, or a flyover connecting the bypass with the existing Route K toll road.

While both options showed improvements for some movements during certain periods, neither option was found to have an overall positive effect.

In terms of presenting the results to the client, Paramics proved extremely useful. We had started out with three models:

• Year 2011 base model.
• Year 2031 structure plan without the bypass.
• Year 2031 structure plan with the bypass.

…and added two more to show the latter two with two right-turn lanes at certain intersections, and finally added the scenarios with the extra roundabout and the flyover, giving us seven models, with AM, IP and PM peaks for each one.

Not surprisingly, with 21 scenarios our reports contained copious tables of data relating to delays and levels of service. By far the most effective way of describing the outcomes was to just run the model in front of the client, which gave a simple visualisation of the intersections involved, clearly identifying where, when and why queues formed. It was then a simple case of referring back to the data tables to get the appropriate data for a particular approach or movement.

TDG has recommended further calibration and a possible expansion of the model to cover a wider area as the best way forward, and we are currently waiting on a decision from the client.

21 June 2010