86 (MBTA bus) Wikipedia
The Massachusetts Bay Transportation Authority operates the 86 bus between Sullivan Square and Reservoir/Cleveland Circle via Harvard. It connects the Orange Line (Sullivan) with the Red Line (Harvard) and the B, C, and D branches of the Green line. It can provide a faster connection between these locations than traversing the "hub and spokes" of the MBTA's subway services. The 86 route is heavily used by those associated with the Boston College, Harvard, and WGBH communities. Few riders traverse the route from Sullivan Station to Cleveland Circle; instead, it is used primarily for shorter rides.
The 86 was an early bus route, added between the start of bus operations in 1922 and 1925. The original route ran between Union Square, Allston and Union Square, Somerville. This stayed until September 1977, when a rush-hour extension (made full-time April 1981) was made to Sullivan Square, supplementing the 91. In December 1989 an extension and realignment was made to the other end. The new route splits from the old route north of Union Square Allston and runs over the former 63 route to Reservoir. At the same time, the 66 was extended north from Union Square to Harvard to keep service north from Union Square. The 63, which had run between Reservoir/Cleveland Circle and Central, was discontinued; the part not covered by the 86 extension was part of the 70 route.