Just thought this may be interesting for robotics people.
9 years ago I played with Asoru robots, they did run 0.43m/s by default, we tuned to 1.2m/s and 1.8m/s, but the line following speed was less.
Two years ago Google search led me to this speedy line following robot. In 2013 "Thunderstorm" robot won a line following contest with 3.1m/s(!) speed on average(!!): https://www.youtube.com/watch?v=cvkveIf2o9g
Last year I did a lot of experiments with my Motor Test Station (MTS): https://forum.arduino.cc/index.php?topic=331722.0
The MTS record I achieved with two cheap 14.8V motors was 51.72km/h or 14.37m/s: http://stamm-wilbrandt.de/en/#MTS.50
Yes, that was radial movement, and I know that linear movement with these motors will be much slower.
Yesterday I saw this video https://twitter.com/HermannSW/status/726077983862231041
Puma BeatBot can do line following runs at speeds up to 44.8km/h(!) or 12.4m/s on stadium track and be even a training partner for Usain Bolt ("all the runner has to do is enter the distance they want to race, the time they want to beat, place it down on the track and go").
There are not much details, but it seems the 44.8km/h can be achieved on the straight line only -- anyway, a cool piece of robot.