the lines have no power in them, in any case, if you only hang on to one line and go not touch the other line or ground, then you are all fine. You can sit on 1000 volts ac if there is no ground connection. This is why birds sit on the lines and not get fried. Now if the bird takes a dump and his waste stretches down to to connect with the wire below, then he is fried. This is why snakes get friend because they climb on the pole and then try to get on the wire when part of their body is still on the pole.
So here is the trick to getting out of your car if a live electrical cable falls on to your car. The trick is to stay inside the car as the rubber tires are insulating you from ground. You will be fine. But if you must jump out, make sure you jump out with your whole body flying out and landing on the ground without having any part of your body touching the car. if at any instant your body is still touching the car's metal body and you touch ground with your leg, you are deep fried.
AZB