A. 
These are traffic rules and orders regulating traffic upon streets open to the public in the Town of Chelmsford and repealing all other bylaws in conflict herewith, ordained by the Selectmen of the Town of Chelmsford as follows.
B. 
Wherever in these rules and orders the following terms are used, they shall have the meanings respectively ascribed to them in this section:
AUTHORIZED EMERGENCY VEHICLES
Vehicles of the Fire Department (fire patrol), police vehicles and such ambulances and emergency vehicles of municipal departments or public service corporations as are designated or authorized by the Chief of Police.
COMMERCIAL VEHICLE
Any vehicle being used in the transportation of goods, wares or merchandise for commercial purposes.
COMMERCIAL VEHICLE, HEAVY
Any commercial vehicle of 21/2 tons in capacity or over.
CROSSWALK
That portion of a roadway ordinarily included within the prolongation of curb and property lines at intersections or any other portion of a roadway clearly indicated for pedestrian crossing by lines or other markings on the surface.
INTERSECTION
The area embraced within the prolongation of the lateral curblines or, if none, then the lateral boundary lines of two or more streets or highways which join one another at an angle, whether or not one such street or highway crosses the other.
MOTORIZED SCOOTER
Any scooter with two or more wheels that is gasoline or alcohol fueled or electrically powered. (This definition does not apply to wheel chair or mobility scooters equipped with a seat.)
[Added 7-19-2004]
MOTOR VEHICLE
Every vehicle, as herein defined, which is self-propelled.
OFFICIAL TRAFFIC SIGNALS
All signals, not inconsistent with these rules and orders, placed or erected by authority of a public body or official having jurisdiction for the purpose of directing, warning or regulating traffic.
[Amended 10-4-1999]
OFFICIAL TRAFFIC SIGNS
All signs, markings and devices, other than signals, not inconsistent with these rules and orders, placed or erected by authority of a public body or official having jurisdiction for the purpose of guiding, directing, warning or regulating traffic.
[Amended 10-4-1999]
PARKING
The standing of a vehicle, whether occupied or not, upon a roadway otherwise than temporarily for the purpose of and while actually engaged in loading or unloading or in obedience to traffic regulations or traffic signs or signals.
PEDESTRIAN
Any person afoot.
SAFETY ZONE
The area or space officially set apart within a roadway for the exclusive use of pedestrians and which is protected or is so marked or indicated by adequate signs as to be plainly visible at all times.
[Amended 10-4-1999]
SIDEWALK
That portion of a street between the curblines and the adjacent property lines.
TRAFFIC
Pedestrians, ridden or herded animals, vehicles and other conveyances, either singly or together, while using any street for purposes of travel.
TRAFFIC CONTROL SIGNAL
Any device using colored lights or words, or any combination thereof, whether manually, electrically or mechanically operated, by which traffic is alternately directed to stop and to proceed.
VEHICLE
Every device in, upon or by which any person or property is or may be transported or drawn upon a public highway, excepting devices moved by human power or used exclusively upon stationary rails or tracks.