It’s no accident that teen driver fatalities have decreased more than a third in the past five years. The frontal lobe of the brain is crucial for controlling judgment, emotions, decision-making, and awareness required for operating a motor vehicle. And on a related note, it’s no accident that California was recently ranked the country’s safest state for teen drivers by US News and World Report. The common thread among these two morsels of good news? Graduated license laws for teen drivers.

Brain Development Research Supports Graduated License Laws for Teen Drivers

Based on new information from the National Institute of Mental Health, scientists and some safety experts have concluded that at age 16, teen brains have simply not achieved the full maturity essential for driving. In short, the parts of the brain, including the brain’s frontal lobe, that are responsible for motor skills and emotional maturity are the last to develop, reaching full maturity around age 25. See our brain development infographic for a visualization and a more detailed explanation of how the brain matures. Researchers have found that the frontal lobe of the brain is the region used for driving, as it plays a crucial role in motor skills and emotional maturity essential for safe and responsible behavior on the road.

This research adds significant support for the movement to strengthen graduated license laws for teenagers. Such laws gradually bestow driving rights upon teenagers as they reach important milestones. In California, for example, teenagers can drive at 16 but do not earn unrestricted driving privileges until age 18.

Overall, teens are dying less behind the wheel because state governments are also taking teen driving more seriously in matters besides graduated license laws. “It’s not that teens are becoming safer,” said Russ Rader of the Insurance Institute for Highway Safety. “It’s that state laws enacted in the last 15 years are taking teens out of the most hazardous driving situations.” Rader points to laws curbing driving at night and with other teenagers as the most important.

Graduated license laws have already caught on and are law in 49 states and the District of Colombia. Only Wyoming has not implemented the safety laws, which helps to explain why the small western state has the country’s worst driving record (60 of 100,000 teens killed in accidents). But the brain development information explains why laws are so necessary and that states should continue to promote safety when it comes to teenagers.

Areas of the brain and their functions

Frontal Lobe:The most important for driver functions, the frontal lobe monitors motor skills and emotional maturity. Lack of development can explain an increased desire to take risks, and the inability to perform complex maneuvers.

Temporal Lobe:The section of the brain most responsible for memory skills and language recognition. An undeveloped or damaged temporal lobe could make learning road rules or motor skills more difficult.

Parietal Lobe:This important sensory location has two primary functions: the integration of senses to form perceptions, and the representation of these perceptions in the world around us. Nearly all visual and audible actions involve the parietal lobe.

Occipital Lobe:The center of visual perception system, the occipital lobe is essential to our ability to drive safely. An undeveloped or damaged occipital lobe can lead to hallucinations or blindness.

Cerebellum:After the frontal lobe, the cerebellum has the most impact on motor skills essential for driving. It also monitors emotions related to fear and pleasure, which can inspire dangerous or reckless driving behavior. The cerebellum plays a crucial role in driving as it is responsible for fine-control during movement execution. This fine-control is essential when performing prepared maneuvers with a vehicle, ensuring precise and safe driving actions. The cerebellum is also involved in motor control, coordinating the fine movements necessary for driving tasks such as starting, turning, reversing, and stopping.

Medulla:Most known for essential body functions we rarely think about: the cardiac, respiratory, vasomotor centers. As the part of the brain that monitors breathing, heart rate, and blood pressure, the medulla is least susceptible to damage.

It probably comes as no surprise that brain size does not equal intellectual or emotional maturity. A growing consensus among the scientific community about teen brain development has revealed the precise implications this fact has for teen drivers. Although the brain is 80 percent developed at adolescence, new research indicates that brain signals essential for motor skills and emotional maturity are the last to extend to the brain’s frontal lobe, which is responsible for many of the skills essential for driving.

The new research, first released by the National Institute of Mental Health, suggests that emotional immaturity, not inexperience, is the primary reason that teenage drivers are responsible for far more car accidents than any other age demographic.  The most important aspect of brain development for drivers is the spread of white matter, the process that helps brain cells communicate more efficiently. The first and second stages of brain development, which occur before people become adults, over-produces brain cells, but lacks an adequate mechanism to process them.

At What Age is The Teen Brain Fully Developed?

The teen brain is not fully developed until at least age 25. When adults reach age 20, white matter begins to spread, from the back of the brain forward, usually completing this process between 25 and 30 years of age. The section of the brain most responsible for driving skills is the frontal lobe (shown above), which manages the body’s motor skills, emotional maturity, and aversion to taking risks. A dearth of white matter here explains why teenagers are much more likely to speed, disobey traffic signs, and lose control of their vehicles.

The white matter revelation has led some safety experts to suggest raising the minimum driving age to 18. But others have said this is an unnecessary change that would place an undue burden on parents. What’s more common is a push for the implementation of stricter graduated licensing laws, which would impose a multi-tiered licensing system to ease teenagers in to the responsibilities of driving without a parent in the car.

The NHTSA recommends that each state implement a three-tiered graduated license system. This would begin with a learner’s permit, progress to an intermediate license with certain limitations, and conclude with an unrestricted license.

California’s graduated license program stipulates that teenagers can get their drivers permit at 15 years and six months, at which time they can only drive with a parent or guardian. Once the driver turns 16, he or she is eligible for a restricted license, with which the driver must be accompanied by an adult over 25 for the first twelve months and cannot drive between the hours of 11 pm and 5 am during that period. In 2006, the Insurance Institute of Highway Safety estimated that the graduated license laws had already reduced accidents for 16 year-olds by 23 percent, preventing more than 8,000 accidents and injuries involving teenagers.

Is The Frontal Lobe of the Brain Necessary For Driving?

Yes, the frontal lobe is necessary for driving. Adults mainly utilize the prefrontal cortex, the brain’s rational section, when driving.

The prefrontal cortex plays a crucial role in driving as it is responsible for motor skills, driver functions, and emotional maturity. These functions are essential for safe driving, enabling the driver to perform complex maneuvers and make sound decisions on the road.

Want to learn more? Check out our related resource pages to learn more about brain related injuries and FAQ’s.