Introduced in 1964 as the M-2, the octagonal M-2A traffic signal pole is Standard for use at all traffic signal locations. A 5-foot mast-arm extension can be used to bring the signal farther out over the roadway, if necessary.
The Alliance street lights were introduced in the Lower Manhattan financial district by the Alliance for Downtown New York. The signal pole can be used as a contemporary alternative to the standard M-2A signal pole only in conjunction with nearby Alliance street lights.
Introduced as the S-1 in 1965, the round S-1A signal pole holds pedestrian signals at corners where an M-2A signal pole or a light pole is not necessary. It also holds traffic signals on medians and traffic islands.