How in the world do you do this????

[Importz2k1]

Career Mode, SD-75- Held up by the Highway scenario, 20 mph speed zones. It says medium difficulty ( )
I can have 90% brakes on and speed is still climbing, I throw it in reverse and give it 13% power, works for a bit and the speed goes up past 20 mph. I come to almost a complete stop, but the speedometer says I'm doing 15mph
I finally finished the mission at -1021 pts.

Any tips from you experts?

[Chacal]

Using the F4 hud, the displayed speed is the speed of the last car of the train.
When stopping, this will be greater than the speed of the locomotive until all the slack has been taken in and the train is fully compressed.
Use the F3 or F5 hud to see the speed of the locomotive.