DOT vehicle services ensure commercial vehicles meet federal safety and recordkeeping requirements enforced by the Federal Motor Carrier Safety Administration. Vehicle compliance is just as critical as driver compliance and directly impacts CSA scores, roadside inspections, audits, and out-of-service orders.

Motor carriers must maintain records showing systematic inspection, repair, and maintenance of each vehicle, including annual inspections, DVIRs, repair documentation, and evidence that out-of-service defects were corrected before the vehicle returned to service.

The most frequently cited vehicle violations include inoperative lights, tire defects, brake issues, steering and suspension problems, fluid leaks, and missing or expired annual inspections. Many of these issues are visible and trigger roadside inspections.

A Driver Vehicle Inspection Report (DVIR) documents the condition of required vehicle components at the end of a workday. When defects are noted, carriers must keep DVIRs and proof of repair for at least three months.

Preventative maintenance (PM) is a scheduled program designed to identify and fix issues before failures occur. DOT investigators look for evidence of consistent PM schedules, repair follow-through, and documentation, not just emergency fixes after breakdowns.

Preventative maintenance intervals vary based on vehicle use, engine hours, mileage, idle time, and duty cycle. Many fleets service vehicles anywhere from 5,000 to 45,000 miles or 500 to 1,300 engine hours, depending on application severity.

An ELD electronically records drivers’ hours of service (HOS). Most interstate CMV drivers are required to use ELDs unless a specific exemption applies. Using a revoked or non-compliant ELD can result in violations and out-of-service orders.

Carriers must retain ELD records of duty status (RODS), supporting documents, unidentified driving records, and backup copies for six months, even when switching ELD providers or replacing revoked devices.

ELD management ensures devices remain compliant, data is backed up, unidentified driving is resolved, and records can be produced quickly—often within 48 business hours—during DOT audits or investigations.

Vehicle maintenance violations directly impact the Vehicle Maintenance BASIC and can increase CSA percentiles, trigger warning letters, increase insurance premiums, and raise the likelihood of audits and roadside inspections.