Much of the NICHD research on driving focuses on the risk factors that make young drivers more likely to have accidents. Researchers in the Division of Intramural Population Health Research (DIPHR) have been exploring these issues for several years, conducting a number of studies about crash risks and risky behaviors.
In the Naturalistic Teenage Driving Study (NTSD), DIPHR researchers attached monitoring systems to the cars of 42 new teenage drivers in Virginia and collected data on their driving behavior for 18 months. Analysis of the data showed that:
- Teenagers' rates of "risky driving" behaviors (such as hard braking or fast acceleration) were five times as high as those of the adults in the study, and teens were four times more likely to crash or nearly crash their cars.
- Risky driving may be socially influenced; crashes and near crashes were 96% higher among teens who had "risky friends."
- Having an adult passenger in the car lowered the rate of crashes by teenage drivers by 75%, while having a teenage passenger in the car lowered the rate of risky driving by 18%.
- A pattern of risky driving performance increases the likelihood of a crash or near crash.
Other studies of the NTSD data looked at the rate of crashes and near crashes over a longer period of time, the influence of car ownership, and the rate of hard-braking events.
In a separate study, the DIPHR researchers analyzed data on fatal teen car accidents from the U.S. National Household Travel Survey and found that those at highest risk of fatal crashes were young male drivers with passengers 16 to 20 years of age.
NICHD-funded research also looked at other risk factors for teenage driving, such as gender, alcohol use, and distracted driving. One study found that female involvement in fatal crashes has increased over time, especially for those younger than 20. This is due in part to an increase in risky driving by teenage girls.
The researchers also found that females were less likely than males to be involved in alcohol-related nonfatal crashes, but there was no gender difference related to fatigue or improper maneuvering. A separate study found that, on a test track, teenage drivers were less likely than experienced drivers to notice and respond to a road hazard.
The NICHD also invests in solutions for the safety of teenage drivers. DIPHR researchers developed the Checkpoints Program, a driver education program that encourages parents to supervise their teenage drivers and to model good driving behavior. Parents and teen agree to a series of restrictions to help the teen develop good driving skills over time. These limitations include an initial ban on night driving. Once a month they "check in" with each other, regularly assessing the teen's skill level and removing restrictions as appropriate.
Evaluation in a number of studies conducted by DIPHR researchers has shown that Checkpoints is effective. For example, parents who received Checkpoints materials were more aware of teen driving risks, were more likely to have completed a parent-teen driving agreement, and were more likely to impose restrictions on driving in bad weather and other conditions.
Other research has shown that programs such as graduated licensing, in which new drivers are given privileges gradually over time, can reduce the rate of fatal car crashes. Researchers funded by the NICHD's Population Dynamics Branch found that licensing limits reduce fatal crashes by 8% to 14%, with the greatest benefits coming from restrictions on driving at night and having teenage passengers.
Other driving research supported by NICHD examines voluntary cessation of driving by seniors, among other studies of driving over the lifespan. This research has found that older drivers often give up driving due to financial reasons, rather than health reasons, and that there are significant racial and gender-based differences in the reasons for driving cessation in older adults. (PMID: 22574868 and PMID: 22992714)
Read additional details about NICHD-supported driving risk studies.