When I first considered this question, the words "natural selection" bobbed inexplicably to mind. On examination, however, the main factors are safety and expense. Which one was more important to the people in charge I leave for you to decide.
Their ungainly appearance might suggest otherwise, but school buses are actually pretty safe. On average, only eleven children are killed in school bus wrecks each year, compared with the 5,500 who die in accidents involving other vehicles. On a per-vehicle-mile basis, the school bus fatality rate is one-seventh that of other passenger vehicles. Several factors account for the good record. School buses are taller and heavier than most other vehicles on the road and generally travel at moderate speeds. In a collision, high seat backs prevent kids from being thrown great distances, and impact-absorbing materials soften the blow.
The question remains controversial, however. High seat backs don't help much when a bus is hit from the side or rolls over, and some people think more should be done. The national Parent-Teacher Association, for example, has called for seat belts on new buses. The federal government recently began a two-year investigation of school bus safety that will likely result in new precautions. According to Education Week, more than two dozen state legislatures have considered making seat belts mandatory, although only New York and New Jersey currently require them.
Seat belts wouldn't necessarily make buses safer. On the contrary, some people believe they would increase the number of serious injuries. Shoulder harnesses aren't practical in buses as currently designed, and lap belts are likely to cause more head and abdominal injuries because in a collision the wearer is jerked forward from the waist.
Then we get into the cost-benefit analysis. At $1,800 a bus, outfitting the 440,000 school buses in the U.S. would cost nearly $800 million -- and when the annual death toll is only eleven, how much lower can you go, realistically? Given that three times as many fatalities occur when students exit or enter buses, some people think the money might be better spent educating the all-too-oblivious public that when the school bus's stop sign swings out, it means you.
Why do we feel hot and cold at the same time when we're sick?
--Shannon Gavin, Lisle, Illinois
This is a little complicated. Under normal circumstances, your core body temperature is maintained at a constant level by a glandular control center called the hypothalamic thermostat. During a fever, bacteria and degenerating body tissue give off substances known as pyrogens, which somehow cause the hypothalamic thermostat to ratchet up a notch. A host of physiological mechanisms then kick in to elevate the body's temperature, a process that usually takes several hours. At the outset the body is way colder than the hypothalamus wants it to be, so although you're heating up, you feel cold, experiencing shivering, goose bumps, vasoconstriction of the skin (clamminess), etc.
Eventually you reach fever temperature, and the chills stop. When the fever breaks, the hypothalamic thermostat drops back to normal. You perspire, and because of the vasodilation, your skin becomes flushed and hot even though you're cooling off. Sound a little complicated? All I can tell you is, don't sweat it.
Is there something you need to get straight? Cecil Adams can deliver "The Straight Dope" on any topic. Write Cecil Adams at the Chicago Reader, 11 E. Illinois, Chicago, IL 60611; e-mail him at email@example.com; or visit "The Straight Dope" area at America Online, keyword: Straight Dope. Cecil's latest compendium of knowledge, The Straight Dope Tells All, is available at bookstores everywhere.
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