The body structure of the RDX was designed using Advanced Compatibility Engineering, or ACE, to help maintain the integrity of the passenger cabin in a frontal impact. By distributing an even amount of crash energy around the cabin, the chance of deformation or intrusion into the passenger area is significantly reduced. Due in part to this construction method, the RDX earned 5 star ratings in all of the National Highway, Traffic, and Safety Administration’s frontal and side impact tests. The RDX also scored 4 stars in the rollover test, the highest rating ever awarded an SUV. Since the RDX must contend with a wide variety of vehicle sizes on the road, ACE incorporates a network of load bearing front frame structures that increase the likelihood of two vehicles properly connecting during a collision.