I drive around and no matter what locomotive, there's no buzzing or noise or anything to let me know there some kind of saftey system in place that requires me to press a button or something. Usually when you go over the chucnks of metal between the rails, usually you hear like a bell ring but nothing like that at the momment
Safety systems are disabled by default in TSW. You need to enable them all with Ctrl+Enter or Shift+Enter (depends on loco) or find corresponding individual circuit breakers in the cab and enable them. That'd be AWS, used on british trains