Eli5: it’s said that creating larger highways doesn’t increase traffic flow because people who weren’t using it before will start. But isn’t that still a net gain?

Question

If people are being diverted from side streets to the highway because the highway is now wider, then that means side streets are cleared up. Not to mention the people who were taking side streets can now enjoy a quicker commute on the highway

In: Engineering

Answer 1

Better highways will absorb part of traffic from side streets. This would make commuting by car temporarily more convenient, this would convince more people to get a car and join traffic.

Net result is even more cars on roads.