Metro simulator forums

Was running a 2018 style M5 to Centraal Station activity and discovered a bug, every train leaving Westwoud ends up getting a 40 kph limit going towards Transferium for no apparent reason. Speed limit in the cab is shown as higher (50kph) but the train sticks to 40kph the entire way to its final destination. Even in areas where there was an 80 kph limit, it still acted like there was a 40 kph limit. This seems to be an AI only issue, if the train is human controlled (with ATP on) it will allow for the train to run at the posted limit, but AI keeps it limited to 40.

I encountered the same issue when testing trains with Sjoerd.
From what I recall, it is linked to the '4' sign right before the 's Gravendijk station.
It was placed back when trains were only following in cab signaling. Since, the Sim was updated to also follow speed signs (for Cities Of Thames for instance), since then, the trains limit their speed at 40 from this sign and keep it as this is the only one placed on the whole M4 line.

So it sounds like to me that a clear restriction sign was forgotten to be placed.

That would make sense, the tram has an increase to 80, I guess the M5 track just needs an increase to 60 sign.