Wyoming Truck Weight and Size Limits
Legal limits for a truck in Wyoming without a permit: Interstate axle and gross weights, height, width, and semitrailer length, each with its official source.
Data pending verification
Some official figures this page relies on haven't been confirmed against the source yet. Don't rely on results here until this notice is gone.
What's pending
- weight-limits/states/wyoming
Wyoming limits at a glance
| Limit | Wyoming | Source |
|---|---|---|
| Interstate gross weight | Pending verification | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix B: Summary of State Exceptions to Federal Truck Weight Limits |
| Interstate single axle | 20,000 lb | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B |
| Interstate tandem axle | Pending verification | FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix B: Summary of State Exceptions to Federal Truck Weight Limits |
| Width (National Network) | 102 in | 23 CFR 658.15, Width (eCFR) |
| Height | 14 ft | Wyo. Stat. § 31-18-802(a)(ii) |
| Semitrailer length | 60 ft in a truck-tractor semitrailer combination | Wyo. Stat. § 31-18-802(a)(iv)(B) |
| Grandfathered semitrailer length | 57 ft 4 in | 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) |
Interstate weight limits
Federal law sets the Interstate limits at 20,000 lb on a single axle, 34,000 lb on a tandem, and 80,000 lb gross, with the bridge formula on every axle group (23 CFR 658.17). States may keep higher limits they had before the federal limits took effect ("grandfather rights").
FHWA's Wyoming summary lists a 34,000 lb tandem and 117,000 lb on Interstate highways using Gross Weight Table 1; its exceptions table lists 36,000 lb tandem and 117,000 lb on all National Network routes. Not confirmed.
FHWA on Wyoming: Wyoming has a grandfather provision under Federal law (23 CFR 127(d)(1)(C)) to allow vehicles to operate up to 117,000 lbs. GVW on several routes, including parts of the Interstate System. See the Routes section for a full description of the routes to which this grandfather provision applies.
Bridge formula check with Wyoming limits
A 5-axle tractor-trailer is filled in. Change the spacings and weights to match your rig; the limits for single axles, tandems, and gross are Wyoming's Interstate limits (federal limits stand in where a figure is pending).
Your result
Wyoming limits off the Interstate
FHWA's summary of Wyoming law for trucks in regular operation (no permit), including non-Interstate highways. It reflects state law as of October 1, 2012; check the state for later changes.
- Single axle
- 20,000 lbs.
- Tandem axle
- 34,000 lbs.
- Tridem axle
- 42,000
- Gross weight
- 80,000 lbs. on primary and secondary highways using Gross Weight Table 2 / 117,000 lbs. on primary, secondary, and Interstate highways using Gross Weight Table 1
- Other
- 600 lbs. per inch width of tire / 750 lbs. per inch width of tire on steering axles
Where Wyoming allows more than federal limits
- Wyoming State statute allows for several axle and GVW exemptions for various types of commodities.
Height, width, and length
- Width: 102 inches. States may not set a width limit of more or less than 102 inches on the National Network (23 CFR 658.15(a)). Permits can allow wider loads.
- Height: 14 ft. There is no federal height limit; each state sets its own.
- Semitrailer length: 60 ft in a truck-tractor semitrailer combination
- Grandfathered semitrailer length: 57 ft 4 in. The minimum semitrailer length the state must allow in a tractor-semitrailer combination on the National Network, based on lengths legal in the state on December 1, 1982. Federal law also requires at least 48 ft (23 CFR 658.13(b)(1)).
Over these limits you need a permit. Wyoming oversize/overweight permits (307-777-4376).
Wyoming compared with neighboring states
| State | Gross | Single | Tandem | Height | Semitrailer |
|---|---|---|---|---|---|
| Wyoming | Pending | 20,000 lb | Pending | 14 ft | 60 ft in a truck-tractor semitrailer c… |
| Colorado | 80,000 lb | 20,000 lb | 36,000 lb | 14 ft 6 in | No separate semitrailer length for a l… |
| Idaho | 80,000 lb | 20,000 lb | 34,000 lb | 14 ft | 48 ft |
| Montana | 80,000 lb | 20,000 lb | 34,000 lb | 14 ft | 53 ft |
| Nebraska | 80,000 lb | 20,000 lb | 34,000 lb | 14 ft 6 in | 53 ft including load |
| South Dakota | 80,000 lb | 20,000 lb | 34,000 lb | 14 ft | 53 ft on the Interstate and state trun… |
Sources
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendices A and B · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: FHWA, Compilation of Existing State Truck Size and Weight Limit Laws (Report to Congress, May 2015), Appendix A: Wyoming · Effective Oct 1, 2012 · Last verified Sep 28, 2026
Source: 23 CFR 658.15, Width (eCFR) · Last verified Sep 28, 2026
Source: 23 CFR part 658, Appendix B, Grandfathered Semitrailer Lengths (eCFR) · Last verified Sep 28, 2026
Source: Wyo. Stat. § 31-18-802(a)(iv)(B) · Last verified Sep 28, 2026
Source: FHWA, Oversize/Overweight Load Permits: State permit contacts · Last verified Sep 28, 2026
Limits change, and cities, counties, and posted bridges can set lower ones. Check with Wyoming before you run a load near the limits. Page data last verified Sep 28, 2026.