As controversy continues to swirl around the safety of sport-utility vehicles, federal regulators are expected to start putting SUVs through an actual test rather than a mathematical simulation to determine how likely they are to roll over, according to the Detroit Free Press. But even before it begins, observers question whether such a test could duplicate what really happens on the road, especially because many factors can contribute to rollover crashes. Finding a way to account for driver behavior, road conditions and vehicle characteristics when calculating a vehicle's rollover score would be a major hurdle as the National Highway Traffic Safety Administration (NHTSA) develops its first so-called dynamic rollover test in the next couple of months, according to the Free Press. Testing could start as early as September, NHTSA said. Congress passed a bill requiring dynamic rollover testing after the 2000 recall of millions of Firestone tires of a type involved in deadly rollover accidents with Ford's popular Explorer.