1. (a) A-weighted sound level shall mean the sound pressure level measured by the use of an instrument with the metering characteristics and A-weighting frequency response prescribed for sound level meters.

   (b) Ambulance.

   Every motor vehicle designed, appropriately equipped and used for the purpose of carrying sick or injured persons.

   (c) Authorized emergency vehicle.

   Every ambulance, police vehicle, fire vehicle and civil defense emergency vehicle.

   (d) Civil defense emergency vehicle.

   Every communications vehicle and rescue vehicle owned by the State, a county, town, city or village, and operated for civil defense purposes and equipped and marked as a civil defense emergency communications or rescue vehicle in compliance with the rules and regulations of the State Civil Defense Commission.

2. (e) Combination of vehicles shall mean any device consisting of a motor vehicle and one or more trailers drawn by such motor vehicle.
3. (f) dB(A) means the standard abbreviation for A-weighted sound level in decibels.

4. (g) Fast meter response means that the fast dynamic response of the sound level meter shall be used. The fast dynamic response shall comply with the meter dynamic characteristics in paragraph 5.3 of the American National Standards Specification for Sound Level Meters, ANSI S1.4-1971. This publication is available from the American National Standards Institute, Inc., 1430 Broadway, New York, 10018.

   1. (1) a vehicle operated by officials of the Division of Fire Safety in the Office for Local Government of the Executive Department,
   2. (2) a vehicle ordinarily operated by a chief or assistant chief of a fire department, or a county or deputy county fire coordinator, or county or assistant county fire marshal, or such vehicle when operated in an official capacity by or under the direction of such person, and

   3. (3) a vehicle specifically designed and equipped for fire fighting purposes which is regularly used for fire fighting purposes by a fire fighting unit on property used for industrial, institutional or commercial purposes and which vehicle is owned by the owner or lessee of such property.

      (i) Gross weight.

      The weight of a vehicle without load plus the weight of any load thereon.

   (h) Fire vehicle.

   Every vehicle operated for fire service purposes owned and identified as being owned by the State, a public authority, a county, town, city, village or fire district, or a fire corporation subject to the provisions of subdivision (e) of section 1402 of the Not-for-Profit Corporation Law or a fire company as defined in section 100 of the General Municipal Law. Any of the following vehicles shall be fire vehicles:

5. (j) Ground cover means any of various low, dense-growing plants, such as ivy, myrtle, low weeds or brush.

6. (k) Hard test site means any test site having the ground surface covered with concrete, asphalt, packed dirt, gravel or similar reflective material for more than one-half the distance between the microphone target point and the microphone location point.

   (l) Maximum gross weight.

   The weight of the vehicle unladen plus the weight of the maximum load to be carried by such vehicle during the registration period, or the maximum gross weight for which the vehicle is registered, whichever is greater.

   (m) Motor vehicle.

   Every vehicle operated or driven upon a public highway which is propelled by any power other than muscular power, except (a) electrically driven invalid chairs being operated or driven by an invalid, (b) vehicles which run only upon rails or tracks, and (c) snowmobiles as defined in article 47 of the Vehicle and Traffic Law.

7. (n) Open site means an area that is essentially free of large sound-reflecting objects, such as barriers, walls, board fences, signboards, parked vehicles, bridges or buildings.
8. (o) Relatively flat, when used to describe a noise measurement site, means a site which does not contain significant concave curvatures or slope reversals that may result in the focusing of sound waves toward the microphone location point.
9. (p) Soft test site means any test site having the ground surface covered with grass, other ground cover, or similar absorptive material for one-half or more of the distance between the microphone target point and the microphone location point.
10. (q) Sound level means the quantity in decibels measured by a sound level meter satisfying the requirements of American National Standards Specification for Sound Level Meters, S1.4-1971. This publication is available from the American National Standards Institute, Inc., 1430 Broadway, New York, N.Y. 10018. Sound level is the frequency-weighted sound pressure level obtained with the standardized dynamic characteristic “fast” or “slow” and weighting A, B or C; unless indicated otherwise, the A-weighting is understood
11. (r) Sound pressure level shall mean 20 times the logarithm to the base ten of the ratio of the root mean squared pressure of a sound to a reference pressure of 20 micropascals. The unit applied to this measure shall be the decibel (dB).

12. (s) Traffic railing means any longitudinal highway traffic barrier system installed along the side or median of a highway. For the purpose of this Part, a traffic railing must have at least 35 percent of its vertical height, from the ground surface to the top of the railing, open to free space in order to qualify as an acceptable object within a noise measurement test site. Further, for the purposes of this Part, posts or other discrete supports shall be ignored when ascertaining open free space.

    (t) Trailer.

    Any vehicle not propelled by its own power, drawn on the public highways by a motor vehicle operated thereon, except motorcycle sidecars, vehicles being towed by a nonrigid support and vehicles designed and primarily used for other purposes and only occasionally drawn by such a motor vehicle.

    (u) Vehicle.

    Every device in, upon or by which any person or property is or may be transported or drawn upon a highway, except devices moved by human power or used exclusively upon stationary rails or tracks.

The following terms used in Parts 450-454 of this Title shall have the meanings indicated: