Simple synchronisation saves snarls and sanity

6 September 2009

Peak hour delays can be cut by more than a third – saving motorists millions in lost time and fuel costs – by simply fine-tuning the traffic lights, a new study by leading consultants GHD shows.

Route optimisation trials carried out by GHD transport systems specialists 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.

Mr Monk, who manages the GHD intelligent transport systems team in New Zealand, will present his work at the International Public Works Conference in Melbourne tomorrow.

The avoidable cost of congestion is estimated at almost $10 billion a year in Australia, and could rise to more than double that by 2020, according to the Bureau of Infrastructure, Transport and Regional Economics. Traffic congestion in Auckland is estimated to cost the local and national economy more than $700 million a year.

“Route optimisation, which is essentially the more efficient coordination of a corridor of traffic signals, can significantly cut travel time, and reduce stop-starts and idling time,” Mr Monk said.

“All of these factors have an effect on vehicle fuel consumption, CO2 emissions and safety.

“Our work shows that route optimisation can contribute positively to economic development, accessibility and mobility without major infrastructure works, and at a greatly reduced cost.”

One trial, on five adjacent intersections in Auckland, was estimated to have saved road users a total of 63,453 hours over one year and more than 214,660 litres of fuel. The trial showed potential savings of more than $1 million a year.

A second trial, on nine intersections, reduced peak hour delays by more than 50 percent in one direction, and by as much as a third in others.

But it is not just reducing congestion that is of interest. GHD has also been helping clients to achieve 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 reduce traffic delays.

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 to 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 programs.

“This is another way to meet ongoing demand and a realistic alternative to continuing to physically build capacity. Why not improve the performance of what we already have?” Mr Monk said.

Mr Monk will present his study at the International Public Works Conference at the Melbourne Convention and Exhibition Centre on Monday at 2pm.

For further information, contact:

Sonia Adams

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