A full-scale vehicle testing program which emphasizes experimental determination of the rollover stability of double-bottom tanker configurations is discussed. The testing program is presented in the context of the total research program which included yaw plane and roll plane analytical studies. The baseline Michigan double-bottom tanker is found to have exceptionally low rollover stability in emergency evasive maneuvers. Vehicle modifications are described which improve stability by a factor of two.Test vehicle loading, anti-rollover outriggers, instrumentation, and modification hardware are discussed specifically. Results of dynamic handling tests and low-speed maneuverability tests are presented. Conclusions regarding the stability of individual vehicle configurations as well as overall fleet safety are reached.