Truck brake statistics show how often brake-related defects are found in targeted commercial-vehicle inspections, how recorded violations vary by category, and how enforcement results have changed over time. The figures below cover North America, the United States, Canada, Mexico, and a Michigan crash-involved sample, with each population and measurement period identified.
Key Truck Brake Statistics
The most broadly useful figures include:
- 16,725 commercial motor vehicle inspections were conducted across Canada, Mexico and the United States during Brake Safety Week, Aug. 25–31, 2024.
- 2,149 vehicles had brake-related out-of-service violations in North America during Brake Safety Week, Aug. 25–31, 2024, equal to 12.8% of inspections.
- 1,216 vehicles failed the 20% defective-brakes criterion during North American Brake Safety Week in 2024, representing 56.6% of brake-OOS vehicles.
- 4,898 inspections were covered by Brake Safety Day in North America on May 14, 2024, and 4,328 vehicles had no brake-related OOS violation.
- 570 vehicles had brake-related critical violations during North American Brake Safety Day on May 14, 2024, equal to 11.6% of those inspected.
- 88 vehicles received performance-based brake tester inspections on Brake Safety Day in North America on May 14, 2024, and 4 failed.
- 43.5% braking efficiency was the minimum required by the cited federal and CVSA criteria in 2024.
- 131,339 clamp- or Roto-type brake out-of-adjustment violations were recorded in U.S. MCMIS inspection data during 2022.
- 80,279 automatic airbrake adjustment-system violations were recorded in U.S. MCMIS data during 2022.
- 55,138 U.S. out-of-service brake-adjustment violations met the at-least-20% defective-service-brakes threshold in 2022.
- 32.7% of 407 inspected trucks in the Michigan FACT crash-investigation sample had brake problems.
- More than one-third of 407 Michigan FACT trucks had maintenance defects that would have placed them OOS before the crash.
- 40,458 North American Level I, II and V inspections were recorded during International Roadcheck, May 14–16, 2024.
- 3,387 defective-service-brake violations represented 25.0% of North American vehicle OOS violations during 2024 Roadcheck.
- 13.3% of 38,117 inspected commercial motor vehicles were placed OOS for critical brake-related items during Brake Safety Week 2022.
- 14.1% of 35,080 inspected vehicles had critical brake items during Brake Safety Week 2018 across 57 participating jurisdictions.
Contents
- Key Truck Brake Statistics
- Brake Safety Week Statistics
- Brake Safety Day Data
- FMCSA Truck Brake Violation Data
- Truck Brake Problems in Crash Investigations
- International Roadcheck Brake Statistics
- Historical Truck Brake Enforcement Trends
Brake Safety Week Statistics
CVSA’s 2024 Brake Safety Week was a targeted enforcement event, not a random sample of all trucks. Across Canada, Mexico and the United States, inspectors conducted 16,725 commercial motor vehicle inspections from Aug.
25–31, 2024, and 2,149 vehicles had brake-related OOS violations, a 12.8% rate.
CVSA, “CVSA Releases 2024 Brake Safety Week Results” reports these North American findings:
| Finding | 2024 result | Defined population |
|---|---|---|
| Stand-alone OOS brake violations | 1,355 (63.1%) | 2,149 brake-OOS vehicles |
| Steering-axle brake OOS violations | 217 (10.1%) | 2,149 brake-OOS vehicles |
| At least 20% defective service brakes | 1,216 (56.6%) | 2,149 brake-OOS vehicles |
| Performance-based brake tester failures | 26 (5.75%) | 452 U.S. PBBT inspections |
The 20% criterion means at least 20% of a vehicle’s service brakes were defective. Violation categories can overlap, and OOS means the vehicle was restricted from travel until critical violations were corrected.
Country results were different in scale and denominator:
- Canada recorded 1,926 inspections and 243 brake-related OOS violations, a 12.6% rate.
- Mexico recorded 107 inspections and 6 brake-related OOS violations, a 5.6% rate; the small event count is not a national fleet estimate.
- The United States recorded 14,692 inspections and 1,900 brake-related OOS violations, a 12.9% rate.
CVSA also recorded 654 lining/pad violations: 382 on power units and 272 on towed units. Among those findings, contaminated lining/pads accounted for 248 violations, cracks or voids for 180, worn lining/pads for 172, and loose or missing lining/pads for 54; these are violation counts rather than unique vehicles or fleet prevalence rates.
Brake Safety Day Data on Defective Brakes
The May 14, 2024 Brake Safety Day campaign covered 4,898 inspections across North America. According to CVSA, “More Than 500 Commercial Motor Vehicles Removed from North American Roadways in One Day Due to Brake Violations”, 570 vehicles, or 11.6%, had brake-related critical violations, while 4,328 vehicles, or 88.4%, had no brake-related OOS violation.
The event’s brake categories were not mutually exclusive:
- 330 vehicles had 20% brake violations, representing 57.9% of brake-related OOS violations.
- 256 vehicles had other brake violations, equal to 44.9% of vehicles with brake-related OOS violations; the category includes defects involving hoses, drums, warning devices and leaks.
- 73 vehicles had steering-related brake violations, or 12.8% of brake-related OOS violations.
Lining and pad findings totaled 185 violations: 62 contaminated, 51 cracked or voided, 49 worn, and 23 loose or missing. Power units had 114 lining/pad violations across 108 units, while towed units had 71 violations across 66 units.
PBBT results covered 88 vehicles, and 4 failed the required minimum braking efficiency, a 4.5% failure rate. The cited federal/CVSA minimum was 43.5% braking efficiency, which is a threshold rather than an average measured efficiency.
The participating-country results were 3,859 U.S. inspections with 448 vehicles OOS, or 11.6%; 1,021 Canadian inspections with 117 vehicles OOS, or 11.5%; and 18 Mexican inspections with 5 vehicles OOS, or 27.8%. Mexico’s percentage has a very small denominator and is not generalizable to the Mexican fleet.
FMCSA Truck Brake Violation Data
The Federal Motor Carrier Safety Administration’s 2023 Pocket Guide reports 2022 U.S. MCMIS administrative inspection records. The January 27, 2023 snapshot contained 2,016,103 vehicle inspections, 3,149,465 vehicle violations and 680,510 vehicle OOS violations across all vehicle-violation types.
FMCSA, “Federal Motor Carrier Safety Administration Pocket Guide to Large Truck and Bus Statistics 2023” lists these 2022 brake-related categories:
| Recorded category | Violations | Geography and period |
|---|---|---|
| Clamp- or Roto-type brake out of adjustment | 131,339 | U.S. MCMIS, 2022 |
| Automatic airbrake adjustment system fails to compensate for wear | 80,279 | U.S. MCMIS, 2022 |
| Brake-hose or tubing chafing/kinking | 56,190 | U.S. MCMIS, 2022 |
| Inoperative or defective brakes | 55,798 | U.S. MCMIS, 2022 |
| At least 20% defective service brakes, OOS threshold | 55,138 | U.S. MCMIS, 2022 |
| Missing or defective trailer ABS malfunction indicator lamp | 55,066 | U.S. MCMIS, 2022 |
| Inoperative brake lamps | 47,916 | U.S. MCMIS, 2022 |
| General brakes | 44,572 | U.S. MCMIS, 2022 |
These are recorded violations, not unique trucks or defect rates for the U.S. fleet. The general-brakes category should not be added to the specific categories, and the source warns that administrative categories should not be summed unless they are explicitly mutually exclusive.
Truck Brake Problems in Crash Investigations
Crash-involved vehicles provide a different lens from roadside enforcement. The FMCSA Large Truck Crash Causation Study analysis of 407 inspected trucks in the Michigan FACT crash-investigation sample found brake problems in 32.7% of trucks.
FMCSA, “Large Truck Crash Causation Study (LTCCS) Analysis Series: Using LTCCS Data for Statistical Analyses of Crash Risk” also reported the following pre-crash inspection findings:
- More than one-third of the 407 trucks had maintenance defects that would have placed them OOS before the crash.
- Air-pressure or hose violations were found in 9.6% of the trucks.
- Steering-axle violations, including brakes, were found in 14.0% of the trucks.
- Any vehicle violation was recorded for 66.1% of the trucks.
- Any OOS item was recorded for 35.1% of the trucks.
This was a Michigan crash sample, not a national truck-brake failure rate. The figures describe conditions found in crash-involved trucks and do not prove that a brake condition caused a particular crash.
International Roadcheck Brake Statistics
North American International Roadcheck ran May 14–16, 2024. CVSA recorded 40,458 Level I, II and V inspections and 9,299 vehicle combinations placed OOS.
According to CVSA, “CVSA Releases 2024 International Roadcheck Results”, defective service brakes were the top North American vehicle OOS violation, with 3,387 violations, or 25.0% of vehicle OOS violations. Other brake violations ranked third with 2,486 violations, or 18.3%.
| Jurisdiction | Inspection or OOS result | Brake-related Roadcheck result |
|---|---|---|
| United States | 42,332 inspections; 7,930 combinations OOS; 23.2% OOS rate | 3,093 defective-service-brake violations (26.5%); 1,919 other-brake violations (16.4%) |
| Canada | Roadcheck country results reported by CVSA | 284 defective-service-brake violations (15.8%); 538 other-brake violations (29.9%) |
| Mexico | Roadcheck country results reported by CVSA | 10 defective-service-brake violations (10.6%); 29 other-brake violations (30.9%) |
The percentages in the country rows use each jurisdiction’s vehicle OOS violations as the denominator, not all inspected trucks. OOS combinations can have multiple violation types.
Historical Truck Brake Enforcement Trends
CVSA’s historical campaign results show variation across targeted events, inspection mixes and participating jurisdictions. The rates below should not be read as a continuous national prevalence series.
CVSA, “Brake Safety Campaign Results” reports:
| Campaign | Period | Inspections | Reported brake outcome |
|---|---|---|---|
| Brake Safety Week | 2022 | 38,117 | 13.3% OOS for critical brake-related items |
| Brake Safety Week | 2021 | 35,764 | 12% OOS for critical brake-related conditions |
| Brake Safety Week | 2020 | 43,565 | 12% OOS; 5,156 removed from roadways |
| Brake Safety Week | 2019 | 34,320 | 4,626 OOS |
| Brake Safety Week | 2018 | 35,080 | 4,955 with critical brake items (14.1%) |
| Brake Safety Day | 2019 | 10,358 | 1,667 OOS (16.1%) |
| Brake Safety Day | 2018 | 11,531 | 1,595 removed with brake violations |
| Brake Safety Day | 2017 | 7,698 | 14% OOS for brake-related violations |
The 2021 unannounced Brake Safety Day campaign conducted 10,091 inspections on May 26 and placed 1,273 vehicles OOS. The 2018 Brake Safety Week result covered 57 participating jurisdictions, while the other campaigns may differ in participation and inspection selection.