Well as we all know what signal color refers to i mean what it means right? If you see a green light that means the path is clear. When you see the yellow, ok slow down the path is clear but there could be a red signal ahead. And red obviously the path is not available. I experienced that in TSW series that stuff doesn't work as it should be in U.S routes mostly. Doesn't matter if there are physical signalization or virtual signalization like in Harlem line or NY-Stamford line. Ai trains seem doesn't care about signalization mostly. Especially in Harlem line and Stamford line. They are stickin to your ass as they running ass to ass each other. I don't know if it happens in real life as chaotic as in TSW U.S routes then nothing here to say. If it is not then that issue must be solved soon, please. Also in some routes i realized that the signal stuck green after i pass like my train is ignored by the simulation. Like Peninsula Corridor line.
In the US, they have a rule on some passenger lines like the Northeast Corridor where you stop at a red signal and contact the signaller. They will then tell you, if it's clear, to proceed with caution. It allows for trains to run in the same signal block and is a common practice that is represented in game. If you get up to a red signal, contact the signaller and they may let you pass it at a reduced speed.
