on foot

prepositional phrase3

1. •
   On one's feet; walking, jogging or running but not in a vehicle or on the back of an animal.

   • The pub's not far: let's go on foot.
2. •
   In progress or in preparation; active, in operation.

   • [W]ithin a short time it was generally believed at Naples, that a treaty of marriage was on foot between Zeluco and the young lady in question […]. — 1789
3. •
   (no longer used) On the move; astir.