The FMCSA is revising the Motor Carrier Safety Assistance Program (MCSAP) to comply with the congressionally-mandated provisions of the Transportation Equity Act for the 21st Century (TEA-21). This action broadens the scope of the MCSAP beyond enforcement activities and programs by requiring participating States to assume greater responsibility for improving motor carrier safety. These rules will now require States to develop performance-based plans reflecting national priorities and performance goals, revise the MCSAP funding distribution formula, and create a new incentive funding program. These rules provide States greater flexibility in designing programs to address national and State goals for reducing the number and severity of commercial motor vehicle (CMV) accidents. This action also includes conforming amendments to the regulations on compatibility of State laws and regulations affecting interstate motor carrier operations.