holy mother of god they're nuts
This ranks as one of the craziest videos I've ever seen.
Some of the commenters aren't fans of the couple minute preamble of them suiting up in powder blue and heading to the top of the hill, but I think it's perfect -- it adds a nice sense of ritual to the insanity of what they're doing.
The road they're on is a few miles from where I live -- it's Claremont Avenue, and hey start at the top of the hill at the corner of Claremont and Grizzly Peak Boulevard, and then head straight down to Russell Avenue; that's the Claremont Hotel they zoom past right near the end of both runs.
Here's the Google topo map of the route...
It's absolutely nuts to do that on a skateboard.