Yes put a speed sign on it.
There are many available, including invisible ones and metric and imperial.
You have to put them for each direction, also they don't take affect unless a train passes it. So if you put a sign and points A and C, and the train starts at B, it will still have the default 40 until it gets to one of the other points. I normally put an invisible sign in front of every train or section of track where trains start from.
In surveyor -> Click Tracks -> Track side mode -> Search for speed.