Neither, pull a Chris Redfield and "boulder punch" the trolley with a quicktime event to smash it off of the tracks. Provided that you can run fast enough to catch up with it in time that is.

If that doesn't work, go back in time with your time machine and train in running and do arm workouts until you're fast and strong enough to run up to the trolley and punch it over in time. Or maybe change things so that you're never caught in either trolley situation to begin with. I dunno.