946 CMR, § 5.09
Colors and arrow indications in traffic control signals shall have the commands ascribed to them in 946 CMR 5.09, and no other meanings, and every operator of vehicles shall comply therewith, except when otherwise directed by an police officer or by a lawful traffic regulating sign (other than a stop sign) signal or device:
Green: While the green lens is illuminated, drivers facing the signal may proceed through the intersection, but shall yield the right of way to pedestrians and vehicles lawfully within a crosswalk or the intersection at the time such a signal was exhibited. Drivers of vehicles making a right or left turn shall yield the right of way to pedestrians crossing with the flow of traffic.
Yellow: While the yellow lens is illuminated, waiting drivers shall not proceed and driver approaching the intersection or marked stop line, shall stop at such point unless so close to the intersection that a stop cannot be made in safety, provided, however, that if a green arrow is illuminated at the same time, drivers may enter the intersection to make the movement permitted by such arrow.
Red: While the red lens is illuminated, drivers facing the signal shall stop outside of the intersection or at such point as may be clearly marked by a sign or line, provided, however, if a green arrow is illuminated at the same time drivers may enter into the intersection to make the movements permitted by such arrow.
Red and Yellow: While the red and yellow lenses are illuminated together, drivers shall not enter the intersection and during such the intersection shall be reserved for the exclusive use of pedestrians.
Flashing Red: A flashing red lens shall indicate those intersections at which a driver is required by law to stop before entering.
Flashing Yellow: A flashing yellow lens shall indicate intersections at which a driver is required by law to slow down before entering such intersections.
Flashing Green: A flashing green lens shall indicate an intersection or pedestrian crosswalk in use or subject to use by entering or crossing traffic, Drives may proceed only with caution and shall be prepared to comply with a change in the signal to a red or red and yellow indication.
Pursuant to the requirements of 946 CMR 5.09, the Agency is authorizes the placement of traffic control signals at the following locations:
At the Intersection of MacArthur Avenue and Pine Street
At the intersection of MacArthur and Buena Vista Street
At the Intersection of Barnum Road and Patton Road.
946 CMR, § 5.09