The highway closest to our place has been under construction over the past year. Large stretches of the highway are getting wider. This has meant periods of significant disruption and slower traffic in the past months.
And, while I hope this is all for the greater good, widening roads tend to have a fascinating side-effect.
While widened roads see lower traffic at first, they often go back to seeing just as much congestion as they did before. This is because people change behavior to take the “faster routes” and congestion is back on the table.
It is an illustration of supply and demand in real life. When you reduce the cost of driving (time is a big component), drivers will consume more of it.
It is also an example of how actions can sometimes have counter intuitive consequences. So, it helps to be clear about what our goals are. Widening roads are helpful if we want to increase the volume of road-usage.
But if we’re seeking to reduce traffic congestion, we’re better off pursuing a different strategy.
