eli5: would adding more lanes to a freeway/busy street really ease congestion or would you still get bottlenecks?

Question

I mean theoretically adding a lane or two should allow more cars to flow through, or would bad drivers still cause bottlenecks/gridlock despite the added capacity?

In: 28

Answer 1

There are also certain events that block or slow down all traffic (at least in one direction) regardless of how many lanes there are: accidents (because of rubbernecking), emergency vehicles, poorly timed traffic lights, etc — and the likelihood of one such event occurring increases as you add lanes.