Computer models could ease traffic woes

Computer-simulated models could help ease traffic snarl-ups and delays in New Zealand's major cities, new research has found.

Transport engineering experts are investigating how the movement of vehicles on city roads can be more efficiently managed after accidents and breakdowns.

Backed by a $170,000 grant from the New Zealand Transport Agency, University of Canterbury (UC) researchers have found that new technology, including Intelligent Transport Systems (ITS), and better incident management plans, were helping.

UC senior transport engineering lecturer Dr Glen Koorey is working on the project with Professor Alan Nicholson, PhD student Susan McMillan and traffic modelling specialists Aurecon.

Dr Koorey says management of major urban arterials and motorways is traditionally "fairly ad hoc'', relying on manual intervention and "educated guesswork'' to try to redirect or re-prioritise traffic if something unexpected occurs on the network.

"Sometimes, in trying to fix a traffic blockage due to some incident, the treatment may actually result in worse problems over the network as a whole,'' he said.

The research has used computer simulation models of, for example Auckland's North Shore traffic network, together with collected field data, to reproduce the effects that a range of incidents will have on the network.

The latest modelling results show that applying different management techniques to a network following an incident can see big reductions in both average travel times and the average variation of travel times, which was especially important.

"People are often more concerned about the variability of their trip times rather than the absolute duration. They can plan for a longer journey time if they know about it. It is the uncertainty that causes problems,'' Dr Koorey said.

He expects to see his findings used by the urban traffic management centres in New Zealand's main cities in the future.

"We've had a lot of interest in our research from within the transport industry, particularly in Auckland, because of the possible benefits that could come out of it in terms of network management and improved reliability for motorists,'' he said.