Train Speed Automatically Reduced by half?

No signals to begin.
At about 1400ft from the start of a run the speed of a train drops to 1/2 of the selected speed?

Placing a single 04 signal at the 1400ft point causes the train to start at half speed and remain at that speed for the entire run.

Attempting to place added signals constantly ran into the program reverting to a RESTART condition when such condition did not exist at the switch to a driver (AI) status! Clearing that condition resulted in the program consonantly reverting to it when attempting to set driver status.

So I concluded my tests. I could find no reference to the "1/2 speed" event in the WIKI.

I believe that there are several coincident variables at play and testing in that arena is too time consuming.

Hi Boleyd,
I had the same on a 160km high speed track (Rotterdam to Antwerp) in my route,
could only solve it by placing enough signaling the entire route (can use hidden signals if you want)
Have no experience with the unified driver/surveyor.
You could try the old way, so just edit the route pure in surveyor mode, save and exit
then restart route and session and try driving the session.
and yes to make it good takes time (but well worth it)
greetings GM

What was that 04 signal placed at 1400ft showing? If it was stop or even caution then it would affect the speed of an AI train, reducing it to about half. The AI driver always sees much further ahead than a human driver.

The solution has always been to place invisible signals (1 if the 04 is showing caution, 2 if it is showing stop) a reasonable stopping distance (a hundred metres or so) ahead of the visible signal.