It does not. Neither you get any penalty, and AI also ignores them. Sometimes it does not even enforce freight speed limits when the passenger speed limit is higher.
This is why it’s best to know all of your signal speeds on the territory you’re operating over. There are so many different rules governing which speed you can be at when.
On lines without PTC or variations of the such, no there is not an in cab enforcement, as mentioned above, engineers know the signals and what speed they should be on passing the signal. Some roads have set speeds for turnouts and don’t even have speeds posted, again expecting the engineer to know the road’s rules.
Before PTC (and on the secondary lines that still don't have it), the only "enforcement" was the conductor's stern admonition. Now of course even the smallest sin gets you a penalty brake. This was more like Britain, with no specific speeds associated with signals and no enforcement mechanism until very recently, and completely unlike Germany which started installing Indusi (PZB) in the late '30s.
