Oil companies are producing the kinds of transportation changes that eluded environmentalists in the 1990s. They are altering the types of vehicles on the road because of rising prices.

Back when gasoline was about a buck a gallon cheaper, some environmentalists urged politicians to slap a 50-cents-a-gallon tax on purchases at the pump. That would’ve meant a price of about $1.80 per gallon. The idea was to stem the increasingly popularity of large automobiles, especially sport utility vehicles. The government could then use the money to explore alternative fuel sources and automotive technologies. Some deficit hawks encouraged such a tax to reduce the budget deficit.

But Congress couldn’t even be persuaded to close the loophole that subjects “light trucks,” including SUVs and minivans, to more lenient mileage and pollution standards. Now, foreign and domestic oil companies have pushed gasoline prices well beyond $2 a gallon and the price isn’t likely to fall anytime soon.

While it’s too late for the feds to make a U-turn and recoup that money, there is still a significant silver lining to those maddening prices. Americans are increasingly trading in their gas guzzlers for more fuel-efficient, environmentally friendly cars.

A national Harris Poll found that 22 percent of buyers altered their decisions because of fuel prices. Nationwide SUV sales declined by 22 percent in April, according to market researcher J.D. Power and Associates. Meanwhile, smaller SUVs and compact cars have gained in popularity.

A similar trend is taking shape in Washington state. According to a Seattle Times report, sales of pickups for personal use plunged by 15 percent compared with April of last year. Also in April, dealers sold three times as many fuel-efficient hybrids as they did during the same month last year. For overall hybrid sales, the state trails only California, Virginia and Florida. Meanwhile, SUV sales in the first quarter declined by 3 percent.

If these trends continue, perhaps automakers will respond with long overdue improvements in fuel efficiency and pollution controls. The National Research Council notes that the technology is already available. The holdup has always been slack demand from consumers who happily drove larger vehicles.

But the dramatic rise in fuel prices has changed all that. After a steady diet of $50 fill-ups, many consumers have had enough. For them, fuel efficiency is becoming the top consideration when it comes to auto purchases, replacing power, roominess and the feeling of safety that comes with more steel and an elevated view of the road.

High fuel prices are no fun, but there are clear benefits if they put the nation on the road to cleaner air and lighter dependency on oil.