A focal point in the Boston skyline, this unique bridge has twin planes of stay cables in the 745’ main span and a single plane of stays in the back spans. Each of its 116 stay cables is lit with white lights, adding drama to the bridge’s signature at night. GM2 associated with another firm for this bridge and each firm was responsible for 50% of the cable-stay design. 

A shift in cable stay planes provides for both engineering aspects of the design and a visual experience for drivers as they cross the bridge. The south back span is 282’ long and the north back span is 420’ long. Both back spans consist of multi-cell post-tensioned box girders. The three longest south back span stay cables anchor on a “finger” of structural concrete that extends 40’ beyond the bridge deck expansion joint. This unique feature allowed the bridge to be constructed while avoiding interference with an adjacent tunnel structure. 

Boston has warmly adopted the twin pylons of the bridge which have been likened to the masts of a sailing ship. The bridge was named the Leonard P. Zakim Bunker Hill Bridge in honor of the late civil rights leader and a nearby Boston neighborhood.