I’ve found that, until you memorize the starting points, it’s easy to get confused on where segments actually begin. The white line can be difficult to see until you are right up to it, especially in lower graphics modes where it can drop in and out while far away. On watopia, for example, the sprint segment begins at the second tunnel. I thought for the longest time that it was the first, causing me to not be geared properly before the sprint.
Something like a distance or time to segment counter would be good.