Looking on the internet deeply has found these results:

I go to school on foot is the most popular phrase on the web.

i go to school by foot 188 results on the web	I go to school on foot 153,800 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
i go to school by foot. @ i go to school on foot. any further explanation regarding to the usage of ON & BY. Thanks. asked Jul 09 '12 at 10:38 FiO New member. Mar 25, 2011 ... up vote 4 down vote favorite. 1. Which one is correct? I go to school by foot. I go to school on foot. prepositions by on ... Oct 20, 2014 ... I go to school by foot. then there's a strong possibility that they could be marked down. Who knows if the teacher sitting there marking their exam ... Incorrect: I go to school by foot. Correct: I go to school on foot. Incorrect: I congratulated her for her success. Correct: I congratulated her on her success.	I can't believe I'm letting you go to school on your own. Do you go to school on foot every day? Let him go to school on his own. Tom goes to school on foot. Do you go to school on foot or by bicycle? I don't go to school on Sunday. Wanted to go to school on an empty stomach. Do you go to school on foot every day?

i go to school by foot

188 results on the web

I go to school on foot

153,800 results on the web

More popular!

i go to school by foot. @ i go to school on foot. any further explanation regarding to the usage of ON & BY. Thanks. asked Jul 09 '12 at 10:38 FiO New member.
Mar 25, 2011 ... up vote 4 down vote favorite. 1. Which one is correct? I go to school by foot. I go to school on foot. prepositions by
on ...
Oct 20, 2014 ... I go to school by foot. then there's a strong possibility that they could be marked down. Who knows if the teacher sitting there marking their exam ...
Incorrect: I go to school by foot. Correct: I go to school on foot. Incorrect: I congratulated her for her success. Correct: I congratulated her on her success.