Driving carries risks for any driver. But, for teens, motor vehicle accidents are the leading cause of death. Because teens and other inexperienced drivers are still developing good judgment behind the wheel, they are especially likely to engage in risky driving. The NICHD is committed to research on driving risks and ways to effectively limit inexperienced drivers' exposure to risky situations.
Driving Risk: Condition Information
In 2010, nearly 33,000 people died in motor vehicle crashes in the United States. This was the lowest number since 1949, when there were far fewer drivers and cars on American roads.1
Despite advances made in automobile safety and regulations, such as air bags and safety belt laws, motor vehicle deaths remain the leading cause of death for people ages 8 to 34 years.2
What risk factors do all drivers face?
All drivers face risks, but the factor that contributes most to crashes and deaths appears to be inexperience.1Newly licensed drivers, primarily teenagers, have the highest crash rates, but even drivers well into their twenties have higher crash rates than older drivers.
Risk factors for motor vehicle crashes that are particularly elevated among teenage drivers include:
- Teenage passengers2
- Distraction while driving, including from using cell phones and texting3
- Driving at excessive speeds, close following, and other risky driving4
- Drinking and driving. While drinking and driving is not very high among novices, it causes a disproportionate number of fatal crashes. In the later teen years and young adulthood, drinking and driving increases greatly.5
- Driving at night
- Being male. Teenage boys, especially ones with male passengers, are involved in more car crashes than teenage girls. However, the number of females involved in car crashes is increasing.6
- Social norms. Risky driving among teenage drivers is higher among teens who report that their friends drive in a risky manner.4,7
Often, several of these risk factors are present: In particular, teens who text while driving are more likely to have other risky driving behaviors as well, compared to those who don't text while driving. These additional risk factors include drinking and driving and not using a seatbelt.8 In addition, young drivers who own their cars may take more risks. They are more likely to speed, especially at night, and have two or more teen passengers with them.6
A positive factor for teen drivers is the presence of an adult passenger. One study showed that teen crash rates were 75% lower when an adult was in the car.4
What driving situations are riskiest?
According to the Centers for Disease Control and Prevention (CDC), unintentional injuries—including motor vehicle and traffic accidents—are the leading cause of death for those 15 to 44. The CDC provides information about and for teen drivers and their parents, including at-risk groups and ways to encourage safer teen drivers, as well as overall facts and information about motor vehicle safety.
Understanding and reducing risk among new and experienced drivers is an important focus on NICHD's Health Behavior Branch. You can view findings from Branch research on driving risk. This research also informed the NICHD infographic What Parents Should Know About Distracted Driving.
The National Highway Traffic Safety Administration offers information about risky driving, including distracted driving and speeding.
What are some known solutions to risky driving?
Road safety depends on the drivers' good judgment and a reduced willingness to take risks, which, like most habits, develop over time. Anything that improves road safety for all drivers improves safety for young drivers. Some strategies are designed specifically for young drivers to limit exposure to risk while they are developing good judgment and safe driving habits.
Road Safety Strategies Specific for Teenage Drivers
Road Safety Strategies for All Drivers
- Preventing Distracted Driving
- Countering Speeding and Risky Driving
- Use of Safety Belts
- Preventing Drinking and Driving
Laws in all 50 states and the District of Columbia establish graduated licensing requirements for new drivers. Specific requirements vary from state to state, but each licensing program has three stages:1
- Learner stage. In most states, drivers in this stage must always be supervised by an adult. At the end of the learner stage, the driver must pass a test to move to the next stage.
- Intermediate stage. Laws during this stage establish a minimum age requirement and place restrictions on nighttime driving and the number of passengers.
- Full privilege stage. Laws mandate a minimum age, usually 18, for unrestricted driving.
The number of car crashes decreased in states with stronger licensing programs, particularly those with more restrictions.2
The most effective legislation has at least five of the following seven elements:
- A minimum age of 16 for the learner's permit
- A restriction requiring a young driver to have a learner's permit for at least six months before he or she could apply for a provisional license
- A requirement for 50 to 100 hours of supervised driving
- A minimum age of 17 for an intermediate stage license
- Restrictions on driving at night
- A limit on the number of teenage passengers allowed in the car
- A minimum age of 18 for a full-privilege license3
Parents play an important role in the success of graduated licensing. They can determine when teens may test for a learner's permit or a license. They may also supervise practice driving for the provisional driver. In addition, they can help enforce certain conditions, such as no driving at night. Research shows that in families where parents impose stricter limits, teens are less likely to exhibit risky driving behavior.4
NICHD researchers developed the national Checkpoints Program — a driver education program that encourages parents to supervise their newly licensed teens and to model good driving behavior.
One important feature of the Checkpoints Program is a written agreement signed by both parents and teens. In this agreement, parents and teens commit to the conditions under which the new driver will develop good driving judgment. These include not driving in conditions that place drivers at increased risk for car crashes Learning to drive is a process of developing good judgment behind the wheel; the first six months after new drivers receive their licenses are considered the most dangerous.5
With a driving agreement, the parent and teen establish a "checkpoint" in one month. At that point, they will assess the new driver's comfort level with driving on local roads in different situations. In the first checkpoint, these include situations in daylight, when roads are dry, and with no other passenger in the car. After each additional checkpoint, the parent agrees to remove restrictions as long as the teen demonstrates good driving judgment. In addition, the parent commits to providing the teen rides as needed until all of the checkpoints are achieved.
Inattention is a leading cause of crashes. Anything that takes a driver's attention from the road, including dialing, texting, and adjusting cell phones and other electronic devices, increases the risk of car crashes. In addition, tasks that require thought reduce the driver's ability to identify and react to potential road hazards. Currently, 31 states ban all cell phone use by novice drivers. Only 10 states, the District of Columbia, Guam, and the Virgin Islands ban the use of handheld cell phones by drivers of all ages. In all but two of these states, the use of the phone alone is sufficient for a police officer to stop a driver. Texting while driving is now banned in 37 states, the District of Columbia, and Guam.6
In addition to laws regulating the use of cell phones and other electronic devices, general improvements in the driving environment can reduce crash rates. These include7:
- "Rumble strips" (strips of ridged pavement that cause rumbling when driven over) on both the centerline and shoulders of the road
- Wide and visible edge lines
- Easily visible road signs
- Better lighting at night
More than half of fatal crashes involve risky driving, with speeding being the most common factor.6 Strategies to combat these problems fall into four categories:
- Laws. Speed limit laws are effective when they are enforced. Laws that target aggressive or risky driving are not considered effective and are not used frequently.
- Enforcement. Automated enforcement, such as speed cameras, can effectively reduce speeding and crash prevalence. Other types of enforcement, even high-visibility police enforcement, are only moderately effective.
- Penalties and adjudication. These strategies work only moderately well at best.
- Communications and outreach. Public information campaigns on enforcement are effective, but the costs can be high.
Seat belts protect drivers as well as passengers from injury and death.When worn by some in the front seat, a safety belt reduces fatal injuries by more than one-half.8 In vehicles with both safety belts and air bags, both safety features are more effective when used together.9 Thanks to these and other safety features, passenger vehicles are safer now than they've ever been, and injuries from serious crashes are less severe now than they used to be.10
As of September 2013, 33 states and the District of Columbia allow officers to stop a driver solely for violation of a safety belt use law. In 16 states, officials can cite violators only when they are stopped for some other traffic violation. One statehas no requirement for safety belt use.8
In addition to enforcing safety belt laws, the Click It or Ticket campaign spreads awareness of the importance of wearing seat belts and is effective in increasing safety belt use. Safety belt use is highest in states that allow officers to stop a driver solely for violating safety belt laws and that publicize their enforcement of these laws.8
Drinking and driving has declined greatly in the past decade. In combination with the approaches below, social norms about the acceptability of drinking and driving have changed due to public information campaigns. However, drinking and driving and drinking and riding remain high among teenagers.12 The following three approaches can help prevent people from drinking and driving:
- Sobriety checkpoints. These checkpoints give police officers the chance to judge whether a driver is under the influence of alcohol and test the blood alcohol level of an individual if he or she shows signs of intoxication. Expanded use of such checkpoints could save 1,500 to 3,000 lives each year.
- Minimum legal drinking age laws. These laws dramatically lowered the rate of teens driving while intoxicated. Keeping the legal drinking age at 21 and enforcing it helps prevent young, inexperienced drivers from drinking and driving.13
- Driving-prevention devices. Devices called "ignition interlocks" can be installed in cars to prevent them from starting when the driver's blood alcohol level exceeds the limit. These devices are used to prevent drivers convicted of alcohol-impaired driving from drinking and driving. Studies show they reduce re-arrest rates for drinking and driving by about two-thirds.14
Driving Risk: NICHD Research Goals
The ultimate goal of all research at the NICHD is to support the Institute’s mission, an important part of which is “that all children have the chance to achieve their full potential for healthy and productive lives.” For this reason, a major focus of the NICHD research on driving is the search for ways to reduce the risk for injury and death from inexperienced drivers.
Using naturalistic and experimental methods, the NICHD research on driving has goals to determine:
- The nature of motor vehicle crashes and the subgroups most at risk. Current research focuses on teen drivers’ exposure to known risk factors and how the exposure changes over time from licensure, whether their exposure is different from that of adults, and whether teen drivers who own their own cars have higher levels of exposure than teens who do not.
- How driving improves over time. For example, recent studies have compared teen driving patterns with their parents’ driving patterns over the same period: 1) when the teen is first licensed and 2) during the first 18 months of licensure. This is to evaluate the effect of experience on risk of crashes.
- The driving conditions and behaviors associated with crashes. Studies using naturalistic methods have followed new teen drivers for up to 18 months, recording behaviors and driving conditions using video cameras and a variety of other tools.
- The effects of social influences on driving performance. Recent studies have focused on the effects of vehicle passengers on speeding and other risky driving of teen drivers to determine if the age and sex of a passenger influences the willingness of a teen driver to take risks. Other studies have sought to determine how the relative risk of involvement in a fatal crash changes with age and gender of the driver and the passenger.
- Solutions to problems faced by novice young drivers. These include:
- Evaluating the effectiveness of graduated driver licensing programs, which vary in their requirements from state to state.
- Studying the role of parents in implementing graduated driver licensing programs (evaluating the Checkpoints Program).
- Determining if parent-supervised practice driving is associated with better driving performance once a teen is licensed.
- Evaluating components of graduated driver licensing programs such as nighttime driving restrictions and passenger restrictions.
- Assessing the role of race and ethnicity in the effectiveness of driver licensing programs.
- The changing effects of gender on relative risk for crash-related injury and fatality.
Driving Risk: Research Activities and Scientific Advances
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.