[programjames]

Quite the opposite. Consider

  ------        ------
        \      /
         \    /
          \__/

versus

  ------   ------
        | |
        | |
        |_|

The second is higher on average. If you're turning 90° your velocity has to become zero in the direction you're going right now, so you might as well get there as fast as possible.

[anyfoo]

Ah, thanks. Here I thought that the distance that you’re not driving at full speed would be equal in both cases, in which case you want to “minimize the minimum speed time”, but the situation you present, where the distance you drive at minimum speed is equal, makes much more sense of course.