I have just started to experiment with safety systems on non-UK routes, beginning with LIRR. However, I have noticed that there is sometimes a large discrepency between the HUD speed limit and the speed permitted by ATC, occaisionally for prolonged periods. Is this supposed to be the case and how should I react to it?
I’m not sure if it is supposed to be that way, but you should always obey ATC when active or you’ll get an emergency brake application.
The HUD shows the line speed and the ATC is cab signalling which reacts to traffic on the line. You should always drive to the lowest of the two. There are occasions where it limits your speed when the line ahead is clear but that’s just a bug.
The ATC and ACSES systems were always glitchy, this is true for both NEC and LIRR, in which they never worked well or appropriately, and frequently displayed incorrect speed limits when compared to the actual line speeds. For example, in the Penn tunnel you’re only allowed to go at 30mph with ATC on but the HUD says 60mph is the limit, for me when I approach a yellow or reduce speed signal the ATC issues a warning to slow to 15 mph, or else automatic emergency braking is applied. DTG has been aware of this issue but they never did anything to solve it, so now we’re forced to turn off safety system for the sake of staying on time.
