As a pretty regular commuter through downtown San Jose, I have to agree with this. The closer I am to the busiest parts of the city, the safer I feel. The speed limits are generally 25 mph, and I typically ride at about 75% of the speed limit, many cars don't even bother to pass me because they know they're just going to get caught at the next light anyways. It's when I get further away from downtown - closer to home (Milpitas), where where people seem to be in more of a hurry, are more likely to right-hook, pull out in front of you, and are simply less attentive.

Having said that, it all depends on which city we're talking about. I've ridden in SF several times, and none of those times have been very pleasant until I get to an MUP. Drivers up there don't seem to like cyclists very much. Once I get over the G.G. and into Sausalito & Tiburon, it's a different story - certainly less stressful to ride on the streets there.