Crossing the Road in LA

I'm in L.A on research and trying to cross the road. I do not know which way the cars are coming from, and they all seem to be going really fast. I do not understand the whole pedestrian lights/crossing thing and neither, I suspect, do many of the cars. I shadowed a woman across a pedestrian crossing yesterday and she stopped in the middle of the road to argue with a revving truck driver about right of way. I cross the road like I’m on crack cocaine, ducking this way and that, hopping from side to side, jumping with surprise and raising my hands in apology as a car I didn’t see suddenly appears behind me. All the roads are two way and very wide and treacherous for pedestrians. It is truly terrifying. Now that I come to think of it, there are very few pedestrians, and many of them are homeless. Which is kind of how I feel right now.