I know of two cyclists who died by suddenly darting across the crosswalk. In both cases the driver was exonerated because there was no way he could have reacted in time.
Don't dart across the road in a bike. For the same reason moms tell their kids not to run across the road. Improving the markings won't help.
When I use the crosswalk, I stand expectantly next to it but off the road, and wait until the cars stop. Then I cross. I never run out into the street hoping cars see me in time.
Hoping other cars see you in time, especially if you dart in front of them, is just a bad strategy.
I'm not talking about markings, I'm talking about designing crossings so that pedestrians and cyclist don't have to watch out for turning cars and improving traffic lights so that pedestrians and cyclist don't feel the need to run red lights.
Here are two really good videos about this that talk about this:
