http://www.streetsblog.org/2009/05/20/s ... ety-fixes/
these anywhere there's a parking row ending, not just at crosswalks. at crosswalks they give pedestrians a shorter crossing distance which is nice. by being a physical control you can put them mid block in places like Broadway where you have lanes weaving back and forth because of parking and help stop illegal parking
they're also a form of speed control. most people don't like to speed through tight spaces and this causes a virtual bunching up of the road at every crossing spot. it's the next best thing to actually making the lane skinnier.
more trees. I saw one thing that said trees in a tight pattern makes it feel like you're going too fast, being close they move by quickly, which helps people naturally slow down.
I like diagonal crosswalks in lighter used areas, on Main or Grand they'd just add time for everyone because it messes with the light cycles. you can combine a pedestrian cycle with each light cycle with straight crosswalks. with diamond it is it's own portion of the light cycle.
basically, anything that's not a major through street should get them. Wyandotte and Central downtrown would be good candidates.