Climate Crisis: Induced Demand Can Be A Good Thing, For The Right Sort Of Traffic

Induced demand describes a phenomenon where adding addition road capacity actually increases the problem of congestion rather than reducing it. Road users are encouraged to use their cars because of the traffic flow improvements which result from the commissioning of the new road or road space, as more people use their cars because journey times have decreased so congestion returns and journey times end up being the same or longer then they were before the extra capacity was added.

Induced demand can be a double edged sword though, which can be used to improve the problem of traffic congestion, especially in cities where alternative ways of travel exist.

That’s if you’re inducing demand for something other than cars. An example would be the use of segregated bus lanes to reduce the space available for private vehicles and speed buses through congestion. Add in more frequent buses and the net result is that a bus journey becomes much faster and more convenient; and as a result, more attractive to commuters.

That reduction in road space for cars means longer and less pleasant commutes and a desire to switch away from the car.

Another form of transport we should be seeking to encourage is the bicycle. However, when most cycle lanes are painted pieces of road with no real consideration for the way cyclists use their lanes, nor the impact of rider confidence of the proximity of fast moving vehicle traffic. Taking places like Amsterdam as a template, road designers can make cycling a viable alternative to the car by taking road space to create segregated and protected cycle lanes and junctions. By making cycling safer it also becomes attractive to a wider audience. You only have to look at the average Dutch city to see that induced demand works very well indeed for bikes.

None of this should be rocket science for town planners or local councils; but the continued failure to plan around the needs of humans rather than the needs of cars, undermines progress in climate and environmental areas.