The Harlem Line as part of the Metro North Railroad does not use many physical signals in comparison to other routes. Generally, you will only find signals at "interlockings" (junctions), as that is the only place its essential for a train to be commanded to stop. At any other time, the trains are slowed by the in-cab signalling, so the engineer can run on sight. Cab signalling does not have the capability to stop the train at all, only slow it to Restricting.
Therefore, even if you are driving without safety systems enabled it will be important to pay attention to what the in-cab signalling is telling you. This information is also covered in the M3A and M7A introductions, which we highly recommend player's complete before tackling other scenarios or services. These introductions can be accessed from Main Menu > Harlem Line > Explore >Training.
The following is an explanation to what each of the lights mean when lit up on the cab dashboard.
- N means "follow the track speed" - you will need to follow the limit on the display unit, or on the HUD next to "ACSES".
- L means "Limited" and means go no more than 45mph, brake down to it immediately if needed.
- M means "Medium" and means go no more than 30mph.
- R means "Restricting", and means go no more than 15mph (In addition, under Restricting you are also obliged to "drive on sight" - there will always be at least one full section ahead of you without obstruction at 15mph but after that there probably is something so on an R drive being prepared to stop on sight.)