Why we shouldn’t be spending on road widening?

As a country we spend about 20 to 30 billion dollars a year on road widening. Although this might seem like a good investment for our roads, we continuously see road widening not relieving traffic congestion. Due to an economic principle called the law of induced demand it can explain why road widening is only a temporary fix. The law of induced demand says increasing the supply of a good makes it more readily available, reducing its effective cost therefore increasing overall consumption. So relating to road widening, increasing road capacity leads to more drivers from alternate routes that switch to use the main road. For every 1 percent increase in road capacity we see a 1 percent increase in traffic volume. This ultimately restores and even increases the traffic congestion just a few years later. 

Well this is a well known principle amongst transportation engineers. So if we know this, why do we keep widening highways? Well it’s mostly because of the demand. With freeways consistently jam packed most drivers would support widening projects because it’s the fastest and most evident way to ease congestion. This leads to the widening projects getting more resident support leading to more funding for these types of projects. 

We have seen billions of dollars get thrown at past widening projects and we consistently see that they do not work. A great example of this is the I-405 Sepuvelda Pass widening project that completed in 2014. It was a 1.1 billion dollar project that added a 10 mile carpool lane. By 2019 they reviewed the congestion on this freeway and found that commuting times were actually slower than before the project. So we spent 1.1 billion dollars easing congestion for a temporary period to then see the traffic return even worse just 5 years after the project. This is not a singular bad apple either; we see this consistently with many other projects such as the I-5 in Burbank California and the Katy freeway in Houston, which expanded to 26 lanes and still saw congestion rise over time. Still to this day we see so many widening projects getting massively funded, especially in California and Texas. Both of these states have approved recent multi billion dollar widening projects that are just starting construction and are expected to be done by late 2020s and early 2030s.

The US is unique with this issue as most other countries have got their space figured out. The US has a ton of land to work with especially compared to other older countries. These countries are smaller in land mass and had to work around old infrastructure forcing them to get creative about how they move. This is why transportation issues the US sees, have already been figured out in other countries. Most of them dealt with it by improving their public transit. We however are an extremely car centric nation, this forces planners to adjust and invest more time into improving driving conditions and reducing freeway congestion. The transportation engineers and planners know that widening is a bandaid solution. We have to spread awareness on the inefficiency of road widening to see them spend more time and effort researching and implementing multi modal solutions. This will allow us to stop wasting money on temporary fixes and start looking for creative and unique solutions to solve this traffic crisis.