http://agathe.gr/guide/panathenaic_way.html
Panathenaic Way Numerous roads led in and out of the Agora square. By far the most important, however, was the broad street known as the Dromos or Panathenaic Way, the principal thoroughfare of the city ... It seems also to have served as the running track for foot races before a proper stadium was built, and as the training ground for the young recruits of the Athenian cavalry. ... As the race made its way along the Panathenaic Way, the armed passenger was expected to jump on and off the moving chariot.