A hot red Porsche Cayenne SUV driven by Ukraine's number two traffic cop from the elite "Kobra" division swerves it way through heavy traffic on one of the more fashionable boulevards of Kiev. With eight lanes and little movement the impatient driver cuts off a high level politician in his black Toyota Landcruiser SUV. The politician accelerates and attempts to halt the Porsche but receives only "the finger" for his efforts. Well, that and the license plate number which is eventually tracked down, ending, not only the police career of the offender, but the existence of the entire "Kobra" unit.

This tale, outlining one of the few examples of traffic law enforcement in modern day Ukraine, is the entertaining centerpiece of an article on the woes created by the monthly flood of thousands of new cars onto the streets of Kiev. Sales are reportedly up by 50 percent over last year and, because of poor planning and little traffic violation enforcement, cars "routinely drive on the sidewalks." Clearly the situation is out of control.

[Source: The Earth Times]

Cars braking up ahead and full roads were recently pegged by mathematicians at the Universities of Exeter (in England), Bristol and Budapest, as two main causes of traffic jams. Reuters is reporting on research at the University of Utah's Traffic Lab that will add another item to the list: cell phones.

The reason that cell phones back up the highways is awful similar to why cars braking ahead does: little actions add up to big delays when the roads are full. The researchers conducted a study with 36 college students and ran them through a series of freeway scenarios. Reuters says that:

The drivers used a hands-free phone during half their trips and no phone in the other half. They were told to obey posted speed limits and use turn signals but the rest of the driving decisions were up to them. What they found is that when the drivers were distracted by a phone conversation, they made fewer lane changes, drove slower and took longer to get where they are going.

On average, people on cell phones finished the 9.2 mile courses between 15 and 19 seconds later than the\ drivers who were not distracted. Extrapolate this to the nation's highways, and we can see how each of those slowpokes on cell phones slows down traffic flow a little bit. With 10 percent of the drivers in the U.S. chatting while they drive, that adds up to a lot of 15- to 19- second delays. That means more time with the cars running and more gas wasted. So hey, hang up and drive greener.

[Source: Reuters]

If you sit in a some gridlock this holiday season, you might come to the end of the line of cars and realize, hey, there's nothing there. No accident, no police on the shoulder, just a bunch of cars that aren't getting where they want to go. Over at the Universities of Exeter (in England), Bristol and Budapest, mathematicians now think they've figured out why this happens (and wastes lots of gasoline in the process).

The short answer: braking and full roads. When there are between 10 and 15 vehicles on a one-kilometer stretch of highway and the front one hits the brakes, a "backward travelling wave" is created that can sometimes lead to traffic jams. As Dr. Gábor Orosz of the University of Exeter's School of Engineering, Computing and Mathematics, said in a statement: "As many of us prepare to travel long distances to see family and friends over Christmas, we're likely to experience the frustration of getting stuck in a traffic jam that seems to have no cause. Our model shows that overreaction of a single driver can have enormous impact on the rest of the traffic, leading to massive delays." He continued: "When you tap your brake, the traffic may come to a full stand-still several miles behind you. It really matters how hard you brake - a slight braking from a driver who has identified a problem early will allow the traffic flow to remain smooth. Heavier braking, usually caused by a driver reacting late to a problem, can affect traffic flow for many miles."

This seems like a problem with no solution. Not braking could lead to accidents, which certainly don't make the highways easier to travel on. And removing cars from the road would be appreciated by many, until public transportation becomes a better option, it ain't gonna happen. So, if you get stuck on the way to or from grandmother's house this year, at least you now kind of know why.

[Source: University of Exeter via Scientific American]