Air Bag Not Deploy problems of the 2008 Chevrolet 2500

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 10/5/12 near newcastle, wy a railroad employee was operating vehicle on the railroad tracks when it struck standing equipment at approx 15 mph. Airbags did not deploy and rail employee was injured. 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.