• 2007: 0.175 per 100 million VMT;
• 2008: 0.171 per 100 million VMT;
• 2009: 0.167 per 100 million VMT;
• 2010: 0.164 per 100 million VMT; and
• 2011: 0.160 per 100 million VMT.
(For comparison, it is noted that the fatality rate for all vehicle accidents in the United States in 2009 was 1.13 fatalities per 100 million VMT.4 The extent to which these and other goals have been met is discussed later in this chapter.
Finding 7-1. The wording of 21CTP Safety Goals 1 and 2 as now written might be subject to misinterpretation by some as allowing the compromise of safety in the effort to improve fuel consumption.
Recommendation 7-1. The Partnership should review the wording of its safety goals and consider rewording them so as to unambiguously state that safety will not be compromised in reducing fuel consumption.
Combination trucks (defined as tractor-trailer and single-unit trucks towing trailers) are involved in about 75 percent of the fatalities resulting from medium- and heavy-duty truck and bus accidents.5 In 2009, a total of 3,380 fatalities were due to large-truck crashes—this was a reduction of 20 percent from 4,245, the number of fatalities in 2008. Of the 3,380 fatalities in 2009, 2,551 were occupants in the other vehicle, and 503 were occupants of the truck (DOT, 2010b). It is typically the case that in truck accidents involving two vehicles, 75 percent or more of the fatalities involve the occupants of the other, usually smaller, vehicle. In accidents involving both a light vehicle and a large truck, the driver of the light vehicle is cited as being at fault most of the time, with some studies showing the driver of the light vehicle at fault as much as 78 percent of the time (see NRC  for more detail and additional references). Most of the fatal crashes involving trucks occurred in rural areas (64 percent), during the daytime (67 percent) and on weekdays (80 percent) (DOE, 2010).
Only about 300 fatalities occur each year in accidents involving truck Classes 5 and 6 combined, primarily because of their typically lower speed in urban daylight settings and many fewer miles traveled compared to Class 8 trucks (DOE, 2010).
Total fatalities for bus-related accidents in 2008 were 307, of which 41 were occupants in motor coaches.6 Commercial buses represent a very small percentage of fatal crashes, only 0.5 percent of the total. Very few fatalities occur due to school bus accidents. In 2009 occupants in a school bus had 3 fatalities, although 91 pedestrian fatalities were associated with school bus accidents.7
More details regarding the nature of heavy-duty-truck and bus accidents can be found in the NRC Phase 1 report (NRC, 2008, Chapter 7), on the NHTSA website, or in the University of Michigan Transportation Research Institute’s Trucks Involved in Fatal Accidents Database.8 Because the vast majority of fatalities and injuries associated with truck and bus accidents are due to combination-truck accidents, most of this chapter focuses on technologies that might reduce combination truck accidents.
Vehicle design and performance characteristics play an important role in truck crashes. The 21CTP places emphasis on technology that can enhance truck roll stability, improve braking performance, and reduce jackknifing. Additional crash avoidance technologies include driver warning, driver assist, and driver monitoring as well as onboard safety system monitoring (DOE, 2010). In addition, the DOT is exploring technologies to improve the frequency and thoroughness of in-service truck inspections. Many crash-avoidance technologies such as electronic stability control (ESC) and roll stability control are commercially available.
For research on heavy-truck safety, most of it devoted to crash-avoidance study, the NHTSA has an annual budget of about $2.1 million. The FMCSA budget is approximately $17.4 million, including analysis and research.
Several crash-avoidance technologies are addressed in this chapter: (1) braking and stability control, (2) collision warning, (3) safety system diagnostics, (4) driver behavior and performance, (5) smart roadside, and (6) intelligent transportation systems.
Braking and Stability Control
Material prepared by the NHTSA suggests that improved braking performance could reduce heavy-duty-truck accidents, particularly those for which the truck would rear-end another vehicle.9 In 2009, the NHTSA published a final rule on amend-
5 Unless otherwise noted, accident statistics cited in this chapter are for the United States.
6 L. Loy, DOT, FMCSA, “Overview of DOT Truck Safety and Productivity Activities,” presentation to the committee, September 8, 2010, Washington, D.C.
9 R. Kreeb, DOT, NHTSA, “Overview of DOT Truck Safety and Productivity Activities,” presentation to the committee, September 8, 2010, Washington, D.C.