I read state data the same way every time: start with the total, then split it until the split stops telling me anything new. Wyoming is a good example, because the headline number is high enough to make people stop reading, and the category split is where the useful information is.
Across the 39 months in this extract, August 2023 through October 2026, Wyoming recorded 38,840 inspections. Those inspections produced 76,024 violations, and 20,102 of those violations were out-of-service. The Wyoming state page has the same figures laid out by category if you want to check my arithmetic against it.
The rate is a ratio of violations, not trucks
The out-of-service rate in this data is out-of-service violations divided by total violations. For Wyoming that is 20,102 divided by 76,024, or 26.4 percent. The national figure in the same window is 2,265,247 divided by 12,832,668, or 17.7 percent.
That number answers one question: of the violations written, how many were serious enough to park the vehicle or driver. It does not tell you how many inspections ended with an out-of-service result. The extract doesn't break that out, so I won't guess at it.
The per-inspection figures give a different view. Wyoming averages 1.96 violations per inspection and about 52 out-of-service violations per 100 inspections. Both are worth keeping in mind, because a state can post a high rate by writing many violations on each inspection, or by writing a normal number of violations that happen to be severe.
Splitting it by category
The extract breaks the data into three groups: driver, vehicle, and hazmat. The three don't add up exactly to the totals, so treat each as its own slice.
Driver. Wyoming logged 25,779 driver violations, with 6,055 out-of-service. That's 23.5 percent, against a national driver rate of about 24.0 percent. Wyoming is close to the national line here.
Vehicle. Wyoming logged 49,357 vehicle violations, with 14,047 out-of-service. That's 28.5 percent, against a national vehicle rate of about 23.9 percent. This is the category doing most of the work. Vehicle violations make up roughly two-thirds of everything logged in the state, and vehicle out-of-service violations are the largest single block in the out-of-service total.
Hazmat. Wyoming logged 609 hazmat violations, with 194 out-of-service. That's 31.9 percent, against a national hazmat rate of about 26.6 percent. The sample is small, so I'd read this as a signal to look at, not a settled finding.
The short version: Wyoming's overall gap over the national rate comes mostly from vehicle and hazmat results. The driver side tracks the country.
Why the vehicle side matters more than the count suggests
Roadside vehicle inspections check the equipment that is on the truck at that moment. Most of what gets written up there is the kind of condition a driver can catch before leaving the yard: brakes, lights, tires, and the rest of the walk-around items. That makes the vehicle category the one where a pre-trip habit changes the outcome most directly.
A high vehicle out-of-service share does not mean Wyoming trucks are worse. It means the violations found on vehicles in Wyoming are more often serious enough to stop the vehicle. Those are different claims, and the data only supports the second.
What this data cannot tell you
This is aggregate state data. It does not show carrier size, route, time of year, or which enforcement officers did the inspections. A state's enforcement focus also shapes the numbers. If an agency puts more effort into vehicle checks on a particular corridor, the vehicle rate goes up without the underlying fleet changing.
The 39-month window is long enough to smooth out a bad quarter, but it is still one window. Treat the figures as a starting point for questions, not as a grade.
Key takeaways
- Wyoming's out-of-service rate is 26.4 percent against a national 17.7 percent, measured as out-of-service violations over total violations.
- Driver results sit close to the national rate. Vehicle results (28.5 percent against 23.9 percent) drive most of the gap.
- Hazmat is above the national rate, but the sample is small.
- The state's 1.96 violations per inspection is a separate measure from the out-of-service rate, and both matter.
- If you run through Wyoming, pre-trip vehicle checks carry more weight than the driver-side numbers alone would suggest.
If you want to compare Wyoming against other states on the same measures, the map and the insights index are the quickest way to do it.