why doesn’t more lanes help mitigate traffic?

Question

I’ve always heard it said that building more lanes doesn’t help but I still don’t understand why. Obviously 8 wouldn’t help anymore than 7 but 3, 4, or maybe 5 for long eways helps traffic filter though especially with the varying speeds.

In: Other

Answer 1

The more lanes you add the less traffic there is so more people drive thus creating more traffic. It’s called induced demand and it’s a fairly well understood phenomenon.