Media Release
14 December 2009

Optimisation Could Save $50 Million

Motorists could save millions in lost time and fuel costs without the need to invest in new road works, according to a series of trials conducted by leading infrastructure consultancy firm GHD.

The Auckland Regional Transport Authority (ARTA) and the Auckland Traffic Management Unit have begun working with the firm to create a regional route optimisation programme for Auckland.

“Route optimisation, which is the more efficient coordination of a corridor of traffic signals, can significantly cut travel time, and reduce stop-starts and idling time,” said Blair Monk, who manages the GHD intelligent transport systems group in New Zealand.

GHD has ascertained that full route optimisation throughout the Auckland region would result in overall savings of $50 million per year. Traffic congestion in the region is estimated to cost the local and national economy more than $700 million a year.

The route optimisation trials carried out by GHD transport systems professionals Blair Monk and Tim Booth found that better coordination of traffic signals could reduce fuel consumption by at least 10 percent and cut travel time by more than 13 percent for city road users.

One trial, carried out (on behalf of the Energy Efficiency and Conservation Authority (EECA)) on five adjacent intersections in Auckland, was estimated to have saved road users a total of 63,453 hours and more than 214,660 litres of fuel over one year. The trial showed potential savings of more than $1 million annually with optimisation of those intersections.

The optimisation of another key arterial consisting of nine intersections resulted in reduced peak-hour delays by approximately a third. Optimisation of further arterial routes is achieving similar results.

“Approximately 10 routes have already been optimised due to local councils recognising the benefits of the technique to reduce congestion on key arterials,” Mr Monk said. “However, the programme that is being developed is designed to provide a coordinated approach across Auckland to tackle the most severe congestion first. In addition, as traffic patterns change over time, every site will be revisited every three years, maintaining the most efficient coordination of traffic lights.”

Mr Monk said the ideal timeframe for route optimisation in Auckland would be five years, with a spend of $10.5 million over that time, and an ongoing spend of $1 million per year to maintain optimisation beyond that.

“Route optimisation has an effect on vehicle fuel consumption, CO2 emissions and safety, and our work shows that it can contribute positively to economic development, accessibility and mobility without major infrastructure works, and at a greatly reduced cost.”

But it is not just reducing congestion that is of interest. GHD has also been achieving other objectives through route optimisation, including improving the safety of pedestrians and cyclists and promoting public transport use. For example, signals can be configured to reduce the amount of traffic through a town centre by encouraging an alternative route, or to give pedestrians priority over cars by making crossing times more frequent. In one city, where a new cycle lane was disrupting traffic on a key arterial route, route optimisation helped improve safety and eliminate the traffic delays that had been caused by the cycle lane.

Route optimisation can also be used to give priority to public transport – without delaying other traffic. An innovative solution gave priority to buses, but only when they were running late, improving travel times for all road users.

Mr Monk said governments were beginning to see the economic and environmental benefits of investing in route optimisation, but he said ongoing funding for route optimisation needed to be identified to reduce traffic congestion and energy use in the transport sector. He said more funds should be allocated to route optimisation programmes. “This is another way to meet ongoing demand, and a realistic alternative to continuing to physically build capacity. Why not improve the performance of the roads we already have?”

He said that under a supercity model, the process would be simplified, with a single budget for transport-related expenditure throughout the Auckland region.

ends

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