Traditional sport utility vehicles -- beloved by automakers, berated by safety experts and burned by radical environmentalists -- may have finally peaked in popularity after a decade of growth, according to a Reuters report. What's on the rise in their place are "crossovers," vehicles that offer the look, space and traction of an SUV but resemble cars under the sheet metal, rather than the pickup-truck base of traditional SUVs designed for off-roading and hauling heavy loads, according to Reuters. "Very few people are jumping boulders in Sedona (Arizona) every day," said Paul Taylor, chief economist for the National Automobile Dealers Association (NADA). "They want a car that's practical for their daily lives, and with these ... they continue to enjoy the flexibility of SUVs, and get much of the comfort of a car and near the economy of the car." The shift comes as SUVs of all stripes have sparked a small but strident backlash in recent months, according to Reuters. Activists have run television ads linking SUV ownership and terrorism, while environmentalists have stepped up campaigns for higher fuel economy rules. And the top U.S. auto safety regulator this week warned automakers that if they didn't build safer SUVs, they faced stricter government regulation. But Jeffrey Runge, the head of the U.S. National Highway Traffic Safety Administration (NHTSA), also said that crossovers offered improved safety, and pressed for more models. "Responsible car companies will do this in the absence of the federal government," he said in a speech to the Automotive News World Congress. "They're already at work."