[sgc]

Crosswalk tunnels tend to be dirty (urine etc.) and can be dangerous. I don't think they are an ideal solution for a city like LA.

[kalleboo]

How about crosswalk bridges? These are common here in Japan. http://photos.wikimapia.org/p/00/03/29/24/45_big.jpg

[icebraining]

It's often hard to make them accessible, though :(

[MereInterest]

Agreed. Not only that, but if they are accessible, the ramps can add another 100 yards of walking or so. I timed it out once, and a full cycle of the lights occurred during the time that it took to cross the ramp.

[undersuit]

I used to use a pedestrian bridge that had a circular ramp to get up both sides and an elevator. The elevator needed a key though, so I guess you did have to know where and how to get the key if you need to use the elevator.

[kaybe]

Also, the constant stairs are a huge annoyance when you walk the city, especially if you have heavy things or any kind of wheeled thing with you. (And it also holds for ramps.)