Sometimes, we get an empty street segment when the light turns green. It's not usually longer than 1 mile until the next traffic stop. 28 mph for only 1 mile is not that hard to do.

Daytime flashing lights and keeping to the center of the roads make it safer. It's unsafe to go that fast on the bike lane.

But my average speed would only be 15 mph. It's not often I get empty segments to hit 28 or even 30 mph. At most, I only get three opportunities to do this on commutes.