A vehicle includes a floor structure and one or more tubular rocker structures. Each rocker structure includes an outer cladding and/or an inner structure extending across an interior space of the rocker structure. At least one acceleration sensor is connected to a central portion of the floor structure to detect acceleration resulting from a crash event. The vehicle may also include pressure sensors that detect changes in pressure in the door cavities that result from side impacts. The cladding and/or inner structure of the rockers reduce the time required to detect acceleration due to a side impact on the rocker structures.