The Main Street
The central street of the Cardo is 40 feet (12 m) wide and is lined on both sides with columns. The total width of the street and shopping areas on either side is 70 feet (22 m), the equivalent of a 4-lane highway today. This street was the main thoroughfare of Byzantine Jerusalem and served both residents and pilgrims. Large churches flanked the Cardo in several places.
Read more at http://www.bibleplaces.com/cardo.htm