Within MCSIP, carriers with potential safety problems are identified and prioritized for an on-site review using the Motor Carrier Safety Status Measurement System (SafeStat) prioritization methodology developed for the PRISM program. MCSIP is a data-driven process that uses current safety event information such as crashes, inspections, driver violations, compliance review data and other data to assess and monitor motor carrier safety performance. Safety events are assigned to the motor carrier responsible for safety of the motor vehicle and are weighted according to severity, frequency and time since the occurrence.

Carriers identified as high risk by SafeStat must enter MCSIP. MCSIP prescribes an appropriate set of treatments to improve safety performance for these carriers, ranging in severity from a warning letter to a Federal Out-of-Service (OOS) order and revocation of vehicle registration privileges. After initial success with both SafeStat and MCSIP, the Federal Motor Carrier Safety Administration (FMCSA) expanded the use of both programs nation-wide.

Carriers are given information on safety performance. This allows concerned personnel to take steps to improve safety and helps them understand how safety performance can impact a carrier's ability to operate. For example, when carriers are given a warning letter, a copy of their most recent safety evaluation summary is also included.

SafeStat and MCSIP are data driven processes. Increasing the quality and accuracy of the available data improves the accuracy and effectiveness of these programs. Efforts are made within MCSIP to keep safety and census data current. For example, when vehicles are registered in PRISM states, the United States Department of Transportation (USDOT) number assignment and census data are verified to assure the accuracy of the data. A focus of the compliance review is to gather, validate and correct safety data.

There are four general instances in which the FMCSA will order a motor carrier to cease interstate operations:

1. When the motor carrier receives a final unsatisfactory safety rating from the FMCSA as set forth in 49 Code of Federal Regulations (CFR) part 385 and the Transportation Equity Act for the 21st century (TEA-21);
2. When, after exhausting all due process options, the motor carrier fails to pay Federal fines levied from FMCSA enforcement actions as set forth in 49 CFR part 386 and Section 206 of the Motor Carrier Improvement Act of 1999;
3. When the motor carrier is determined to be an imminent hazard; and,
4. When a new entrant fails an audit or does not schedule an audit within 18 months.