The Chief of Police is authorized and, as to those signs and signals required in this article, it shall be his duty to place and maintain, or cause to be placed and maintained, all official traffic signs, signals, markings and safety zones. All signs, signals, markings and safety zones shall conform to the standards as prescribed by the Massachusetts Department of Transportation.
No driver of any vehicle of any description shall disobey the instructions of any official traffic control signal, sign, marking, marker or legend unless otherwise directed by a police officer.
Every driver of any vehicle, railway car or other conveyance approaching an intersection of ways where there exists facing him an official sign bearing the word "Stop," or a flashing red signal indication, such signs or signal having, apart from these rules and orders, the written approval of the Massachusetts Department of Transportation, and such approval being in effect, shall, before proceeding through the intersection, bring such vehicle, railway car or other conveyance to a complete stop at such point as may be clearly marked by a sign or line, or if a point is not so marked, then at the nearer line or crosswalk of such intersection. In the case of a line of two or more vehicles approaching such stop sign, or flashing red signal indication, the drivers of the second and third vehicles in any group shall not be required to stop more than once before proceeding through the intersection. This section shall not apply when the traffic is otherwise directed by an officer or by a lawful traffic regulating sign, signal or device.
A list of locations where stop signs are authorized is on file in the office of the City Clerk.
A list of locations where right turns on red lights are prohibited is on file in the office of the City Clerk.
Whistles used by any police officer in directing traffic shall have the following meanings:
A. 
One blast of a police officer's whistle at an intersection means all moving vehicular traffic shall come to a stop, at which time pedestrians may cross the street.
B. 
Two blasts of a police officer's whistle followed by a warning hand signal shall indicate termination of the pedestrian crossing interval, and vehicular traffic shall proceed on receiving a hand signal from a police officer.
C. 
Three or more blasts of a whistle given by a police officer shall indicate the approach of an authorized emergency vehicle, when both vehicular and pedestrian traffic shall immediately stop or proceed as directed by the police officer.
A. 
Colors and arrow indications in traffic control signals shall have the commands ascribed to them in this section and no other meanings, and every driver of a vehicle, railway car or other conveyance shall comply therewith, except when otherwise directed by an officer or by a lawful traffic-regulating sign (other than a stop sign), signal or device, or except as provided in § 325-37B.
B. 
In no case shall a driver enter or proceed through an intersection without due regard to the safety of other persons within the intersection, regardless of what indications may be given by traffic control signals.
C. 
Definitions.
(1) 
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 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.
(2) 
Right, left and vertical green arrows. When a right green arrow is illuminated, drivers facing the signal may turn right. When a left green arrow is illuminated, drivers facing the arrow may turn left. When a vertical green arrow is illuminated, drivers facing such signal may go straight ahead. When a green arrow is exhibited together with a red or yellow lens, drivers may enter the intersection to make the movement permitted by the arrow but shall yield the right-of-way to vehicles and pedestrians proceeding from another direction on a green indication.
(3) 
Yellow. While the yellow lens is illuminated, waiting drivers shall not proceed and any driver approaching the intersection or a 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.
(4) 
Red. While the red lens is illuminated, drivers facing the signal shall stop outside of the intersection, or such point as may be clearly marked by a sign or line; 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.
(5) 
Red and yellow. While the red and yellow lenses are illuminated together, drivers shall not enter the intersection, and during such time the intersection shall be reserved for the exclusive use of pedestrians.
(6) 
Flashing red. When a red lens is illuminated in a traffic control signal by rapid intermittent flashes, and its use has been specifically authorized by the Massachusetts Department of Transportation, drivers shall stop before entering the nearer line or crosswalk of the street intersection, or at a stop line when marked, and the right to proceed shall then be governed by provisions of MGL c. 89, § 8.
(7) 
Flashing yellow. A flashing yellow lens shall indicate the presence of a hazard and drivers may proceed only with caution.
(8) 
Flashing green. A flashing green lens shall indicate an intersection or pedestrian crosswalk in use or subject to use by entering or crossing traffic. Drivers may proceed only with caution and shall be prepared to comply with a change in the signal to red or yellow indication.
A. 
All of the territory within 200 feet of the premises of each hospital in this City is created and established as a zone of quiet. The Chief of Police is authorized to erect and maintain in a conspicuous manner within this area such signs and markings as are necessary to designate it as a zone of quiet.
B. 
The Chief of Police may temporarily establish a zone of quiet upon any street where a person is seriously ill. Such temporary zone of quiet shall embrace all territory within a radius of 200 feet of the building occupied by the sick person. Such temporary zones of quiet shall be designated by the Chief of Police by placing at a conspicuous place in the street a sign or a marker bearing the words "Illness — Quiet Zone."
Any person who wilfully defaces, injures, moves, obstructs or interferes with any official traffic sign, signal or marking shall be subject to the penalty provided in Chapter 1, Article I, of this Code.
No person or corporation shall place, maintain or display upon or in view of any street any unofficial device, sign, signal, curb marking or street marking which purports to be or is an imitation of or resembles an official traffic device, sign, signal, curb marking or street marking or which attempts to direct the movement of traffic or which hides from view any official sign, signal, marking or device. The Chief of Police is empowered to remove every such prohibited sign, signal, marking or device or cause it to be removed without notice.
A. 
Sections 325-3, 325-4, 325-29, 325-30, 325-41, 325-69, 325-73, 325-75, 325-76 and 325-79 of this chapter shall be effective only during such time as official signs are erected and maintained in each block designated in the provisions of such sections and located so as to be easily visible to approaching drivers.
B. 
Regulations relating to one-way streets shall be effective only during such time as a sufficient number of official signs are erected and maintained at each of the exits for each one-way street, so that at least one sign will be clearly visible for a distance of at least 75 feet to drivers approaching such an exit.