I've always wanted to do this. My commute route goes over two freeways. One is running south-north and the other goes east-west. I have to do a long detour just to cross the second freeway, thanks in part for the city since they destroyed the pedestrian bridge that allowed for a more direct route. It was raining quite a bit this morning, which caused congestion, accidents, even some deaths.

So after my replacement co-worker arrived (late, because of traffic), I went home in the rain (after a nightshift). As I passed over the southbound freeway I notice the traffic jam, so I thought, why not? Entered the freeway, rode on the wide shoulder I had for myself, riding around 32km/h, passing parked cars, and got out at the next exit, where both freeways connect.
Easiest commute ever. I wish I could ride there everyday. Freeways are so convenient.