Protocol is key. I have attended road sprint clinics. We go to a road that has a hill that flattens out with street lighting poles on the side of the road. Generally, each pole is about 200 meters apart. The drill is started at the top of the hill and one uses the hill as a lead out. On the way down the hill, one gets into the sprint gear, in the drops and when on passes the first lighting pole one sprints to the second one and notes the terminal speed. Depending on road conditions, wind and flatness of the road, the terminal speed will vary. However, the training is to generate speed going into the start of the sprint, know where the starting and finishing point is and then sprint for 200 meters.

If there is not a hill to simulate the lead out, then it takes a lot of effort to come up to sprint speed at the start of the 200 meters

I am a 500 meter trackie so my finishing speed of the 500 meters is generally around 35.5 mph on the indoor track. However, my time is not a function of terminal speed but acceleration from the standing start.