In 2012 the US Congress directed the Federal Motor Carrier Safety Administration (FMCSA) to improve commercial motor vehicle safety through the MAP-21 Act. NHTSA reported to the US Congress in 2015 that heavy truck rollover crashworthiness should be improved. To that end NHTSA sent a letter to the president of SAE asking if improvements in test methods could be suggested that would result in improvement of rollover performance. In this study we review the performance of heavy truck cab structures that meet the requirements of J2422 and suggest a framework for improving rollover crashworthiness for heavy trucks.