Traffic congestion costs 

New figures from Copenhagen show that traffic jams cost society a small fortune in lost time. For the first time, a study is under way to determine the extent and consequences of congestion on an interconnected series of roads in Greater Copenhagen. The first calculations, based on three selected test stretches in the Greater Copenhagen area, indicate major traffic congestion costs.

The calculations shows that the total congestion costs on Motor Ring Road 3 are DKK 1.8/km if one additional car enters the road; of this, congestion represents DKK 1.75/km. On the arterial road Ellebjergvej in the inner city, the total cost is DKK 7.20/km for every extra car on the road; DKK 7 of this is congestion cost.

"We’re talking about a loss of millions on lost work and leisure time. After many years of being spared the serious traffic jams seen in major cities like London and Brussels, Copenhagen has seen increasing congestion for some time. Queues and delays are becoming part of everyday life for many people," says COWI Project Manager Erling L. Hvid.

Detailed information

The figures come from a research project, Project Congestion, supported by the Ministry of Transport and the Danish Transport Council and implemented by COWI together with the Municipality of Copenhagen, the Greater Copenhagen Authority, Copenhagen University, the National Road Directorate and the Centre for Traffic and Transport Research.

Project Congestion has two phases. In the first, which has recently finished, methods were devised to quantify congestion and techniques developed to calculate its socio-economic costs. The methodology was tested on three selected stretches in the Greater Copenhagen area - a motorway, an arterial road and a city street. The information is based on detailed data collected with a passenger count system and automatic and manual counting. Based on this data, an analysis has been made of how travel speed and traffic density are dependent on a number of parameters such as traffic flow and road capacity. In phase two, these techniques will be used to determine the overall scope of congestion on a selected road network in Greater Copenhagen and then to develop a simple system that will produce a continuous monitoring of the situation.

Recognized problem

"The congestion project makes no proposals for how the problem could be solved. It is a barometer of what the situation is and how it is developing. The first step is to recognize that there is a problem - then it's up to the politicians to decide what is to be done about it," explains Erling L. Hvid.

"One thing, however, is quite plain. The problem of traffic congestion is growing at an explosive rate, even with small increases in traffic. In the long run, it will make little difference to leave an hour earlier or later. All that means is that the rush hour will quickly extend further."

"To alleviate the problems politicians must consider to expand the road network, to make better use of the existing road network, to introduce parking restrictions and road tolls, to locate workplaces rationally, to persuade people to take the bus or hop on their bikes, to start car pool systems or to work from home," says Erling L. Hvid.

Knowledge of congestion helps road planners in Århus

Information about road congestion is now being used for the first time as the basis for prioritizing country road investments. COWI is studying a number of roads in Århus County to determine congestion levels. But other counties too are showing interest in the congestion data.

New techniques are now making it possible to incorporate congestion data in traffic planning. The new methodologies are based on a determination of travel speed and traffic density, the latter however on motorways alone, as there is no simple method of evaluating density on stretches of urban roads.

"With the continually increasing traffic loads in major towns in Denmark, the new techniques developed in this project are a much-needed contribution to traffic planning. They are well suited for all large towns with congestion problems, both at home and abroad," says COWI Project Manager Erling L. Hvid.

The development work was done as part of the research project, Project Congestion, that COWI conducted together with the Municipality of Copenhagen, the Greater Copenhagen Authority, Copenhagen University, the National Road Directorate and the Centre for Traffic and Transport Research.

Published 04.07.2002