Editing Vehicle size class (section)

====FHWA====
Developed in the 1980s, the [[Federal Highway Administration]] 13-category classification rule set is currently used for most federal reporting requirements and that serves as the basis for most state vehicle classification systems.<ref name="FHWA">{{cite web|url=https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/13091/002.cfm|work=[[Federal Highway Administration|FHWA]]|title=Chapter 2. Introduction to Vehicle Classification - Verification, Refinement, and Applicability of Long-Term Pavement Performance Vehicle Classification Rules, November 2014 - FHWA-HRT-13-091}}</ref>

{| class="wikitable"
|+ FHWA vehicle classification definitions
|-
!Class group
!Class definition
!Class includes
!Number of axles
|-
| 1 || Motorcycles || Motorcycles || 2
|-
| 2 || Passenger cars || All cars <br />Cars with one-axle trailers<br />Cars with two-axle trailers || 2, 3, or 4
|-
| 3 || Other two-axle four-tire single-unit vehicles || Pick-ups and vans<br />Pick-ups and vans with one- and two- axle trailers || 2, 3
|-
| 4 || Buses || Two- and three-axle buses || 2 or 3
|-
| 5 || Two-axle, six-tire, single-unit trucks || Two-axle trucks || 2
|-
| 6 || Three-axle single-unit trucks || Three-axle trucks<br />Three-axle tractors without trailers || 3
|-
| 7 || Four or more axle single-unit trucks || Four-, five-, six- and seven-axle single-unit trucks || 4 or more
|-
| 8 || Four or fewer axle single-trailer trucks || Two-axle trucks pulling one- and two-axle trailers<br />Two-axle tractors pulling one- and two-axle trailers<br />Three-axle tractors pulling one-axle trailers || 3 or 4
|-
| 9 || Five-axle single-trailer trucks || Two-axle tractors pulling three-axle trailers<br />Three-axle tractors pulling two-axle trailers<br />Three-axle trucks pulling two-axle trailers || 5
|-
| 10 || Six or more axle single-trailer trucks || Multiple configurations || 6 or more
|-
| 11 || Five or fewer axle multi-trailer trucks || Multiple configurations || 4 or 5
|-
| 12 || Six-axle multi-trailer trucks || Multiple configurations || 6
|-
| 13 || Seven or more axle multi-trailer trucks || Multiple configurations || 7 or more
|-
| 14 || Unused || ---- || ----
|-
| 15 || Unclassified vehicle || Multiple configurations || 2 or more
|}

''{{resize|80%|Source: Verification, Refinement, and Applicability of Long-Term Pavement Performance Vehicle Classification Rules, FHWA}}''<ref name="FHWA"/>