Where Commonwealth Avenue reaches Kenmore Square, the MBTA Green Line B branch rises above ground and dominates the center of the roadway through the campus of Boston University and the neighborhoods of Allston, Brighton and Chestnut Hill to the city of Newton and the Commonwealth Avenue Historic District. The section in Newton is made up of two roadways separated by a grassy median lined with trees. The south side of the roadway contains the main, two-lane east-west roadway, with a one-way, westbound "carriage road" providing local access on the north side of the median.