Children’s Hospital of Philadelphia has made safe teen driving a priority, and “CHOP” publishes a superb website about teen driving, found at www.teendriversource.org. If you have not visited, I urge you to do so.
One of the most interesting and useful studies that CHOP has produced on teen driving is one that provides statistical evidence regarding this critical caution for parents of teen drivers: teens who are permitted to have their own cars or to be the primary drivers of a particular car have higher crash rates than those who share a car with a parent or another family member.
In a 2009 publication, CHOP recited these statistics (which, given everything that is on this blog, should be regarded as downright frightening):
- Almost three of every four teen drivers in the U.S. have “primary access” to a vehicle (which I assume means they can drive the car whenever they want, so long as they can obtain the keys and permission; that is, they do not have to wait for someone else to finish using the vehicle).
- Teens with primary access to a car drive about 6.6 hours and 200 miles per week, as compared to 130 miles in 4.3 hours for those who share a car; and
- Crash rates for teens with primary access are more than double those who rely on a shared car.
The hospital’s study admirably compiles and presents the statistical case against giving teens primary access, but it seems to me that the reasons for this marked difference go beyond what can be demonstrated statistically. If a teen shares a car with a parent, the following good things are likely to happen: the parent keeps closer watch on whether and when the teen gets behind the wheel in the first place; the parent is more likely to be attuned to the difference between purposeful and recreational driving; the teen is more likely to have to requisition the keys from the parent; the parent is more likely to make an informed, day-by-day, case-by-case judgment on whether it is safe for the teen to drive; the parent and teen are more likely, before the teen leaves, to put together at least an informal plan for the driving route, passengers, arrival time, check in time, and return time; and the parent and teen are more likely to consider, at least momentarily, whether the teen driving at that particular moment is allowed under the parent teen driving contract that they hopefully have signed.
The hospital’s study also reports that teens with primary access are shown to be more likely to use cell phones while driving. However, curiously, the study did not detect any difference between alcohol or seat belt use between primary and shared vehicles.
At a basic parent-teen level, it seems that what is going on here is that when a teen shares a car with a parent, the parent is more motivated to be proactive, if only to protect the value of the car and the parent’s own convenience, than a parent whose teen has his or her own car. Conversely — no rocket science here — teens just don’t want to face the consequences of crashing Mom’s or Dad’s car.
CHOP’s study is simple, clear, and in line with common sense: buying your teen his or her own car, or giving your teen primary access to a car, substantially increases the risk of a crash, injury, or fatality. By contrast, forcing a teen to share a car reinforces good parenting and oversight across the board.
