Thompson, a former emergency-room physician who lives along the winding five-mile road, claimed that he was merely trying to take a photograph of Stoehr and Peterson, evidence of the way cyclists flout the law in the canyon and flip off residents. A Los Angeles Police Department traffic investigator who arrived on the scene shortly after the incident testified that Thompson told him he 'stopped in front to teach them a lesson.' Suffice it to say that Thompson shouldn't be driving a support vehicle in the Tour de France. Two other cyclists testified that in March 2008, a motorist they believed to be Thompson made a similar maneuver, speeding ahead, then slamming on his brakes. One of these cyclists told the court that the driver tried to hit them again and then sped off, noting that the car was an Infiniti sedan and the license plates -- spelling out an abbreviated form of the medical software company Thompson owns -- matched those of Thompson's car. Obscene gestures, vanity plates -- it's all part of the romance of Southern California driving. Road rage? That's just the inflamed passion part of romance. But anyone who's been paying attention to the road lately probably has noticed a marked, even dizzying, increase in the number of bikes on U.S. streets. Suddenly, they're in bike lanes and traffic lanes, zipping through stoplights, careening around mountain passes and weaving along sidewalks. Census data show that between 2000 and 2008, the number of bicycle commuters increased by 43 percent. And membership in competitive cycling clubs is on the rise, with USA Cycling reporting the number of licensed U.S. racers up 48 percent since 2002. Despite the cozy, granola-esque community spirit this trend might evoke (think helmeted parents riding with their helmeted kids and women in flowing skirts peddling home from the farmers market with baskets full of French bread), the reality is more sobering. Cycling-related accident rates are decreasing, but cycling injuries are getting worse. That suggests that riders may be tangling with something more than a mere fall, like a car door or fender. And although most drivers, mercifully, don't harbor as much animosity as Thompson, I suspect there may be more of him out there than we might like to think. Why? For starters, many people don't know what rights cyclists do and do not have, which pretty much makes them assume they have none. I was in this category myself until I consulted the bicycle laws in the California Vehicle Code and learned that a cyclist has 'all the rights and is subject to all the provisions applicable to the driver of a vehicle.' In other words, you're not supposed to dart through red lights on a bike (shame on you, 80 percent of Lycra wearers in my neighborhood). But guess what: It's perfectly legal to occupy the entire lane, not just hang on the side, if you're going the same speed as traffic. The speed limit on Mandeville Canyon Road is 30 mph (it's 25 mph on most residential Los Angeles streets), which, according to the injured cyclists' GPS data, was about the speed they were traveling when Thompson stopped in front of them. In other words, if you're getting impatient with a 'slow' cyclist in front of you, it's probably because you're speeding. (It hurts me to say this as much as it hurts you to hear it.) So, now that you know, are you going to stop swearing at cyclists? My guess is no. Because there's a larger bone of contention here, which is that cyclists make a lot of us feel like lazy slobs. Whereas drivers sit in an air-conditioned bubble, expending only the energy required to press the gas pedal, tap the brake and change from a '70s classic-rock radio station to an '80s classic-rock station, cyclists are out in the actual elements doing actual exercise. Whereas drivers are consuming calories by eating an entire bucket of KFC over 10 blocks, cyclists are burning calories and consuming nothing but seaweed at home. Whereas drivers' carbon footprints grow more beast-like by the hour, cyclists create no exhaust other than the sweet fatigue they feel as they drift off to saintly sleep at night. Of course, moral superiority is insufferable, but you still shouldn't try to run it off the road or teach it a lesson with your luxury car. You might win on the street, but in court, it's a different story. Daum is an essayist and novelist in Los Angeles. E-mail her at mdaum@latimescolumnists.com 