Yes, blindfolded on a soccer field, I tried to run strides in a straight line, with a timer set to 15 seconds to avoid running off the field and crashing into something. The first time I turned about 90 degrees after 10 seconds. After a few more tries I had +/- 10 degrees accuracy. Eventually set the timer down to 10 seconds and did fast strides, eventually achieving the same accuracy. The idea was that running form starts with reflex action and is altered by visual cues. If the reflexes go in the wrong direction and have to be fixed afterward by visually-directed movements, that should reduce efficiency. I tested the hypothesis by seeing what direction my legs would go if I left them to their own devices, then tried to train myself to run in a straight line by reflex alone. After two sessions I realized the blindfold was unnecessary, I could just run with my eyes closed. This is safer and allows me to test whether I'm drifting during a run.