In a keynote speech at the ITS World Congress in Detroit, senior ITF economist Jari Kauppila presented details of research demonstrating that the economic cost of unreliable travel times by road may rival that of traffic congestion – the area on which transport policy has traditionally focused.

He said: ‘Shifting the focus from reducing travel time to reducing the way in which travel time can vary implies a move away from policies to build new infrastructure, and towards better management of existing infrastructure, as well as providing information to users to enable better planning of their journey.’

He referred to a specific study on the A6 motorway in France, which had showed that effective traffic management could reduce average travel time on a 20km long section by 12%, and reduce the time added by drivers to account for anticipated delays by 45%.

‘Reliability of journey time represents a major road network characteristic that should be recognised when considering investment options,’ said Mr Kauppila. ‘Reliability should therefore be incorporated into cost-benefit assessment.’

According to the ITF, so-called Intelligent Transport Systems can play a key role in delivering the benefits associated with increased transport system reliability. Depending on the project, it says, including journey time reliability as a factor at the project assessment stage may bring user economic benefits of between 10 and 25%.

Active systems aimed at managing travel times on congested road sections have already either been trialled or implemented in various countries worldwide, amongst them Denmark, the Netherlands, Norway, Sweden, Australia, New Zealand and the United Kingdom.