Teenagers are one of the highest-risk segments of the driving public due to inexperience behind the wheel. Now a new study in the UK has shown that getting several teenagers together in a car can make the problem even greater, as much as tripling the risk of a fatal accident.

According to the Association of British Insurers, the greatest period of risk for teens traveling in a group is during the first 30 weeks after passing the driving test, reports The Times. The report itself puts its findings in no uncertain terms: “Young passengers can both distract young drivers and encourage them to drive in a more risky way. Restricting drivers under 20 to carrying just one teenage passenger for the first six months of driving will allow them to gain experience of carrying passengers before having to deal with the distraction of three or four of their teenage peers in the car.”

The incidence of teenage driving deaths has been on the rise in some states, but declining in others, as more graduated systems of licensure are enacted. The Association of British Insurers is using the results of this study to push for a set of restrictions on new drivers during their first six months on the road. Advocates of the study even note that several U.S. states have already adopted similar restrictions with good results: up to 37% fewer fatal teen crashes.

In the UK, 270 deaths or serious injuries could be prevented each year if a law limiting drivers under age 20 to just one teenage passenger were imposed. However, such laws raise the question of enforcement - how can a police officer know a driver is under age 20 from a distance? Moreover, could the law be abused as a pretense for stops and subsequent searches? The potential for abuse of driver rights, and in the U.S., Constitutional rights, is high.

On the other hand, in 2006 teenage drivers caused or were involved in nearly a million car accidents in the U.S., resulting in about 400,000 injuries and 2,541 deaths. The economic cost of these incidents totaled more than $34 billion. So there is ample public policy justification for some encroachment upon teenage drivers' rights.

The question then becomes where to draw the line, and how best to enforce it - and that will be a struggle for legislators everywhere.

Earlier this week, Ford revealed its MyKey feature that allows parents to program their children's cars to stay below certain speeds, prohibit wheelspin, and more. By definition such a system is incapable of tackling the serious issue of driver inattention and distraction raised by this study, and similar concerns of use and required installation of the device as it relates to personal liberty have been raised.