Monday, September 30, 2019

Traffic congestion reconsidered

What lessons can be learned from experiences of different cities in their attempt to deal with traffic congestion?

Increasing road space—does it solve the problem?
In simple words, congestion occurs when demand for road space exceeds supply.
Hence, building new roads or adding more lanes to existing ones might seem as obvious solutions. It surely sounds logical enough: as cities grow bigger, roads serving them should follow the same trend. Drivers should have more space to move if they have wider or new roads, which relieves congestion and makes cars go faster. This argument is frequently used by government officials to elaborate on the importance of new and frequently costly infrastructure projects.

However, it hasn't always turned out this way in practice, and the reasons behind could be found in long-term effects of the induced demand. Induced demand refers to the situation where as supply of a good increases, more of a good is consumed. This implies that new roads essentially create additional traffic which in turn causes them to become congested all over again.