Safety benefits of stability control systems for motorcoach buses
Authors: John Woodrooffe, Daniel Blower, Paul E. Green
The potential safety benefits of electronic stability control (ESC) systems for motorcoach buses operating within the United States are analyzed. "Motorcoaches" are defined as flat-front, high-platform buses equipped for intercity or long-distance travel. In recent years, ESC has increasingly become available as standard or optional equipment on motorcoaches. However, national crash databases do not include information that can be used to identify ESC-equipped buses. Moreover, even if the buses could be identified, the number of cases in available crash data is not sufficient to evaluate the safety performance of the technology in its current stage of deployment, particularly given the low number of motorcoach crashes. In light of these limitations, all recent fatal motorcoach crashes were examined by using information from the accident reports, formal studies of the National Transportation Safety Board, and information in reconstruction reports to estimate the likelihood that the crash could have been prevented or mitigated had the motorcoach been fitted with functioning ESC technology. Results indicate that, if it is assumed that ESC had been fitted to all motorcoach buses, annual savings of $25 million could have been realized from loss-of-control and rollover crashes prevented. Even though the financial benefits for motorcoaches are limited because loss-of-control crash events are rare, the nonmonetary value of this technology is likely to exceed the financial benefits because motorcoaches transport the public and the reasonable expectation is that effective safety technology should be used even if the exposure is low. In particular, the risk of passenger casualties in a high-speed crash is much greater for a motorcoach than for other vehicles because of the large number of people on board.