Not much really, just ALOT of traffic, the exits are well sign posted (they are all number sequentially making it pretty easy to judge when you need to get off). Just have to remember to be in the far right lane to get off instead of the left! Although some express lanes (the far left lane) have dedicated exits as well.
Also whats the deal with the quality of the roads in LA? its all cracked etc. I asked my tour guide on my private tour of L.A. and they were apologetic about the quality of the roads there in L.A. - along with the food and standard of American workmanship in general

Mind you, imagine the traffic chaos that would be caused if they actually closed a lane to properly fix up the quality of the roads






