In the California Transportation Permits Manual (TPM), the minimum
overall tire-to-tire axle width (overall width) of a vehicle in the extra-legal weight
configuration is 2.44 meters. Commercial truck tractor and trailer tandem 1.82 meter
wide axles fitted with new generation wide base single (NGWBS) tires measure 2.34
meters in overall axle width; thus, it is not compliant with the current California
Department of Transportation requirement . Due to the growing application of NGWBS
tires in the market, it is important to understand the vehicle stability characteristics of a
tractor semi-trailer fitted with both dual and NGWBS tire configurations. In this research,
a comparison of duals to NGWBS with both a 50.8 millimeter offset wheel and a 25.4
millimeter offset wheel are presented. A rapid air loss (RAL) event was initiated to
represent a severe scenario in each of the three following maneuvers: straight line, steady
state curve, and a lane change. The data was evaluated and differences between NGWBS
and dual tire-fitted vehicles were compared. While a tire RAL event can be perceived as a
dramatic event, previous studies and driver training events have shown that such a RAL
event is manageable. The conclusion of this work was that a rapid air loss event with
NGWBS tires is as manageable as a dual tire-fitted vehicle, and does not make the system
unstable.