More than 900,000 long-haul sleeper cabs are projected to be on the road by 2030. About half of heavy truck occupant fatalities occur in rollovers. This paper discusses the current status of rollover protection systems for occupants in sleeper cabs and describes the outcomes from example crashes with sleeper cab occupants. A virtual testing methodology for evaluation of current designs under rollover conditions and restraint tests utilizing dummies and humans also are described. The paper includes discussion of finite element models used and their validation. Examples of results associated with various restraint system configurations are presented. The results show that incorporating effective lateral restraint is important in providing protection to sleeper cab occupants under rollover conditions.