Ever since 1974, when Congress adopted the 55-m.p.h. limit to conserve gasoline, Western lawmakers have fought federal efforts to slow down traffic in the wide-open spaces. But faced with evidence that the limit saved both lives and gas, Congress has been unwilling to make any changes.
Now, with gasoline prices dropping and state legislatures growing defiant, some lawmakers are again trying to raise the limits, particularly on rural interstates, where studies show that most cars traveled at 66 m.p.h. last year.
Adding fuel to the movement in Congress this year is the announcement by the Transportation Department that, for the first time, it will withhold highway funds from two states - Arizona and Vermont - because they failed to keep 50 percent of their drivers from exceeding the 55 limit.
"The pressure is on to raise those limits, because compliance is not very good, and the states have no enthusiasm to enforce the law," said Don Sherman, editor of Car and Driver magazine, which has campaigned vigorously to boost the limits in rural areas.
"The fact is the law today simply doesn't fit the reality of American driving."
President Richard M. Nixon signed the Emergency Conservation Act in 1974 establishing the 55 limit as a conservation measure in response to the Arab oil embargo.
But the limit, which Congress made permanent in 1975, also saved lives. Highway fatalities decreased by 9,100 in the first year - the largest one-year drop since gasoline was rationed during World War II. And the National Academy of Sciences estimates that the law still saves between 2,000 and 4,000 lives a year.
Western states bitterly opposed the limit, as did the 1980 Republican Party platform. Despite this, however, no governor has refused to sign the annual pledge to enforce the limit, because the transportation secretary can withhold highway money from any state that fails to keep at least half its traffic at or below the 55-m.p.h. limit.
Still, at least 11 states have weakened speeding penalties by reducing fines and no longer entering violations on the records of motorists caught doing less than 65 or 70 m.p.h.. In Nevada, speeders caught doing less than 70 m.p.h. are fined just $5.
And enforcement of the 55 limit has also diminished. In Nebraska, where motorists caught doing less than 65 face a fine of just $10, the highway patrol issued only 3,918 tickets to drivers traveling between 56 and 65 m.p.h. last year. By contrast, 27,634 tickets were issued to motorists going over 65.
Safety experts argue that such lax enforcement undercuts the law. According to Transportation Department statistics, at least four out of every 10 drivers were exceeding the posted 55 m.p.h. speed in 37 of the 50 states last year.
"If you tell people they're not going to be penalized much for going over 55, you are telling them, in effect, to go ahead and do it," said Mary Dunlap, spokesman for the Washington-based Center for Auto Safety.
Measures aimed at raising the limit have been introduced in both houses of Congress this year. Twenty-nine House members are co-sponsoring a bill to lift restrictions on rural interstates; Exon's bill would give the states the option of raising the limits on all interstates to 70 m.p.h.
"States should be allowed to decide where and how limits should be set," Exon said. "In Nebraska, the highway patrol could better spend time enforcing a 55-mile-an-hour speed limit on the two-lane auxiliary roads, where more than 90 percent of fatalities occur."
In a 1984 report, a National Academy of Sciences panel could not agree on whether to raise speeds on the 31,000 miles of rural interstate in the 425,000-mile interstate system. The report found, however, that 500 more people would die each year if the higher speeds were allowed.
"About 100 years of travel time would be saved in exchange for the loss of an additional life," the report concluded.