What happens every day at this I-5 downtown Seattle highway exit?.
Mostly nothing since the highway gets clogged with cars trying to go to the office so they move slowly.

But outside the peak hours it turns into a trap: an almost empty highway gets you into a short tunnel with a 90 degree turn, no-visibility downtown exit, this is the result:

There are already plenty of signs telling drivers to slow down, but here are some possible solutions that may help: speed bumps to make sure distracted drivers lower their speed, a traffic light before entering the tunnel that stays red and only goes green when it detects the car has actually stopped, permanently closing the exit since it’s almost impossible to give more visibility.

trafficnightmare.net