6-4-2-5: MOTOR VEHICLES:
   1.   It shall be unlawful for any person to operate any motor of a motor vehicle of a eight in excess of four (4) tons (8,000 lbs.) for a consecutive period longer than two (2) minutes while such vehicle is standing on private property and located within one hundred fifty feet (150') of property zoned and used for residential purposes except where such vehicle is standing within a completely enclosed structure.
   This Section shall not apply to buses operated for the transportation of passengers while standing in established bus turnarounds, bus terminals, bus parking lots and bus-storage yards.
   2.   No person shall sell, or offer for sale, a new motor vehicle that produces a maximum noise exceeding the following noise limit at a distance of fifty feet (50') from the center line of travel under subsection 1 of the TEST PROCEDURES Section of this Chapter:
TYPE OF VEHICLE
DATE OF MANUFACTURE
NOISE LIMIT
Motorcycle
Before 1 Jan. 1970
92 dB (A)
Same
After 1 Jan. 1970
88 dB (A)
Same
After 1 Jan. 1973
86 dB (A)
Same
After 1 Jan. 1975
84 dB (A)
Same
After 1 Jan. 1980
75 dB (A)
Any motor vehicle with a group vehicle weight of 8,000 pounds or more
After 1 Jan. 1968
88 dB (A)
Same
After 1 Jan. 1973
86 dB (A)
Same
After 1 Jan. 1975
84 dB (A)
Same
After 1 Jan. 1980
74 dB (A)
Passenger cars, motor-driven cycle and any other motor vehicle
Before 1 Jan. 1973
86 dB (A)
Same
After 1 Jan. 1973
84 dB (A)
Same
After 1 Jan. 1975
80 dB (A)
Same
After 1 Jan. 1980
75 dB (A)
 
   3.   No person shall operate within the speed limits specified in this Section either a motor vehicle or combination of vehicles of a type subject to registration at any time or under any condition of grade, load, acceleration or deceleration in such manner as to exceed the following noise limit for the category of motor vehicle, based on a distance of not less than fifty feet (50') from the center line of travel under subsection 2 of the TEST PROCEDURES Section of this Chapter:
Noise Limits:
   Noise Limit in Relation to Posted Speed Limit.
35 M.P.H.
or Less
Over 35 M.P.H.
Type of Vehicle
Any motor vehicle with a manufacturer's GVW rating of 8,000 lbs. or more, and any combination of vehicles towed by such motor vehicle
   Before 1 Jan. 1973
88 dB (A)
90 dB (A)
   After 1 Jan. 1973
86 dB (A)
90 dB (A)
Any motorcycle other than a motor-driven cycle
   Before 1 Jan. 1978
82 dB (A)
86 dB (A)
   After 1 Jan. 1978
78 dB (A)
82 dB (A)
Any other motor vehicle and any combination of motor vehicles towed by such motor vehicle
   After 1 Jan. 1970
76 dB (A)
82 dB (A)
   After 1 Jan. 1978
70 dB (A)
79 dB (A)
 
   This Section applies to the total noise from a vehicle or combination of vehicles and shall not be construed as limiting or precluding the enforcement of any other provisions of this Code relating to motor vehicle mufflers for noise control.
   4.   No person shall modify or change the exhaust muffler, intake muffler or any other noise abatement device of a motor vehicle in a manner such that the noise emitted by the motor vehicle is increased above that emitted by the vehicle as originally manufactured. Procedures used to establish compliance with the paragraph shall be those used to establish compliance of a new motor vehicle with the requirements of this Chapter. (See also, the MOTOR VEHICLES Section, NUISANCE Chapter of this Title and the MOTOR VEHICLES AND TRAFFIC Title of this Code).
   5.   No person shall sound any horn or audible signal device of any motor vehicle of any kind while not in motion, nor shall such horn or signal device be sounded under any circumstances except as required by law, nor shall it be sounded for any unnecessary or unreasonable period of time.