Cross walks and sidewalks are for pedestrians and bicylists going a pedestrian speeds.
I almost hit a kid today in a crosswalk. Both of us were contributors....I was making a right following behind a big rig and putting more attenting on what the heck lane the big rig was going to end up in than the crosswalk. Kid was barrelling across at 15 to 20 mph....and I didn't see him unitl my son yelled look out.
Part of the danger of cycing in cross walks is that drivers are simplely not attuned to looking for something moving and speeds above that of a pedestrian..........and the mind plays tricks on you.
so speed limit of cross walks is good.
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Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)