ACCESS 21, Fall 2002
Tom Wenzel and Marc Ross
Last spring's Senate hearings on Corporate Average Fuel Economy standards made much about the increased risk Americans would face if forced to give up their SUVs for vehicles that weigh less. To find out whether that risk is real, and whether SUVs really are safer than cars, as some have alleged, we analyzed highway fatality data. Our findings came as a surprise. Suv 2We focused on “driver death rates,” a concept of risk developed by the Insurance Institute for Highway Safety. However, our analysis differs from the Institute’s in two important ways. First, we examine risk not only to drivers of vehicles of a particular type, but also to drivers of vehicles that crash with that vehicle type. Second, we limit our study to recent models having sold enough vehicles to permit statistical analysis.
Brian D. Taylor
Traffic congestion and cities, it seems, go hand in hand. Everyone complains about being stuck in traffic; but, like the weather, no one seems to do anything about it. In particular, traffic engineers, transportation planners, and public officials responsible for metropolitan transportation systems are frequently criticized for failing to make a dent in congestion. But is traffic congestion a sign of failure? Long queues at restaurants or theater box offices are seen as signs of success. Should transportation systems be viewed any differently? I think we should recognize that traffic congestion is an inevitable by-product of vibrant, successful cities, and view the “congestion problem” in a different light.
Theodore E. Cohn
You'll no doubt be surprised to read that transit buses get rear-ended more often than passenger cars do. You’re surprised, I suspect, because buses are so large and obvious. Who could fail to see that bulky bus? Who could fail to know it moves slowly and stops often? These collisions are a tremendous waste of resources. Crashes injure both bus patrons and passengers in other vehicles, damage expensive equipment, cause delays and service disruptions, worsen traffic congestion, lessen acceptance of transit as a travel choice, and they’re expensive. A 1997 estimate found that each crash cost $54,000. Plus, we find, these crashes are largely preventable.
The merger of modern communications technologies and physical distribution systems is transforming many aspects of the shipping industries, including their locations and the way they use space. But these changes are not evidence of the promised dissolution of distance that was expected with the advent of global telecommunications. Instead, electronically sophisticated freight handlers are finding that locational considerations are as compelling as ever. In recent years freight services have been expanding via all modes—trucks, airplanes, railroads, oceangoing ships, inland waterway vessels, and pipelines. As Amelia Regan recently reported in these pages (ACCESS No. 20, Spring 2001), this expansion has been accompanied by the incorporation of new technologies aimed at integrating producers, wholesalers, freight forwarders, retailers, and consumers.
You're driving along the freeway when suddenly everything slows down. A crash? A sudden overload of cars joining the freeway from on-ramps up ahead? Maybe. Sometimes the cause never reveals itself to you—inexplicably, everything just starts moving again. If this happens every day in the same spot, you may develop a theory or two as to why it happens. Would it occur to you that the congestion might be caused not by too many cars getting on the freeway but by too many cars trying to get off? For decades, traffic engineers have been managing freeway congestion by using meters to restrict the rates that vehicles enter the freeway from on-ramps. A metering scheme can often keep cars moving faster on the freeway, and sometimes can even reduce traveler delay systemwide. Realizing these benefits requires metering that is suitably designed, but traffic engineers disagree about what constitutes a suitably designed plan.
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Paul Ong and Douglas Houston
Welfare reform ended America’s public assistance program as we knew it, transforming it from an income-entitlement program to an employment-assistance program. Following its enactment, welfare rolls dropped by more than half, from about 12 million in 1994 to just over 5 million in late 2001. Fortunately, the majority of those who left public assistance found work. Nevertheless, welfare reform still faces a large, and largely unrecognized, problem.