RAILROAD HYRAIL VEHICLE EQUIPPED, AFTER MARKET, WITH HYRAIL WHEEL ASSEMBLIES WHICH ALLOW THE VEHICLE TO OPERATE ON RAILROAD TRACKS. ONCE HYRAIL (FLANGED) WHEELS ARE RETRACTED, THE VEHICLE IS OPERATED OVER THE HIGHWAYS AND PUBLIC ROADS LIKE ANY OTHER VEHICLE. ON 3/16/12 A BNSF EMPLOYEE WAS OPERATING THE HYRAIL VEHICLE ON HWY 34 NEAR TRENTON, NE. A SEMI PULLED OUT IN FROM OF HIM, CAUSING HIM TO REAR END THE SEMI AT ABOUT 65 MPH. DELAYED AIRBAG DEPLOYMENT LED TO HIM HAVING EXTENSIVE INJURIES, INCLUDING LACERATIONS TO HIS FOREHEAD, COLLAPSED LUNGS, SPINE FRACTURES AND RIB FRACTURES. CONCERN IS THAT THE INSTALLATION OF HYRAIL WHEEL ASSEMBLIES MIGHT BE IMPACTING THE AIRBAG SENSOR. THE HYRAIL WHEEL ASSEMBLIES EXTEND APPROX. ONE FOOT OF STEEL FRAMEWORK AHEAD OF THE FRONT AND REAR BUMPERS. THE PLACEMENT OF THESE ASSEMBLIES MIGHT INADVERTENTLY BE AFFECTING AIRBAG DEPLOYMENT IN CRASHES ON THE RAILROAD TRACK AND ON PUBLIC ROADS.