You couldn’t siege a traffic circle today.
The remnants of the Byzantine forces now withdrew to Damascus. The Muslims pursued them. The siege of Damascus became one of the set pieces of the conquest of Syria. To a remarkable extent we can retrace the progress of the siege because of the detailed descriptions of the sources and the preservation of the fabric of the city. The walls of old Damascus, Roman or earlier in origin and continually restored since, are still largely intact. Only at the western end where the city expanded in Ottoman times is the old circuit breached. All except one of the ancient gates survive and they bear the same names today as they do in the early Arabic sources: it is an astonishing example of the continuity of urban geography and architecture through almost fourteen centuries We are told that Khalid b. al-Walid was stationed at the East Gate (Bab Sharqi), Amr b. al-As at St. Thomas’s Gate (Bab Tuma), Abu Ubayda at the now demolished Jabiya Gate on the west side and Yazid b. Abi Sufyan at the Little Gate and Kaysan Gate on the south side.
Hugh Kennedy, The Great Arab Conquests, 79.