by trainbrain
Many rush hour trains have an "L" next to the scheduled times in the further out stops. This means that the train is stopping primarily to discharge passengers and may leave ahead of schedule if ready to do so. I suspect that this allows the comet trains to get ahead of schedule. The Multilevel trains have to deal with the tunnel slots and then the switches at Rahway to go from the NEC to NJCL. That likely makes them 10-15 minutes late while the comet trains are running a few minutes early.