I know locals like to complain about the beltline, but as someone who has driven in LA, SF, Chicago, NY, it is wild to compare it to any big city traffic.
It's not in the same league as LA, NY, or Chicago but definitely up there (albeit during shorter time windows) with Silicon Valley commuter traffic. Part of a common theme of living in Madison where you get downsides of city living- traffic, high taxes, high housing costs- without many upsides such as good public transport, a diversified job market, or a well-developed food scene.