It would be nice if upon decoupling, brakes were applied in an emergency/broken air line fashion. Occasionally trains will separate, either because of poor track setup or lag, and it would be nice if brakes were immediately applied and the train stopped (few things are more frustrating than finishing a 40 minute long trip and realizing you left half the train somewhere between the start and the end!). As a bonus, it's realistic too!

Closing as dupe of #363