As of 2011, all 50 states now have some form of graduated license program, and the evidence about their effectiveness has started to come in the form of studies designed to look at the impact of these laws in general and to assess which forms of the graduated license law seem to be more or less effective.
National Institutes of Health findings
In 2011, when the last state finally adopted graduated licensing, the NIH released a series of conclusions based on the first 10 years of data about the program-the years 1998 through 2007. The findings were clear and unambiguous. Graduated licensing saves lives, reduces overall road fatalities, and, most importantly, works best when there are several stages of learning and responsibility development.
According to the NIH, the programs that were most effective had the following features in common:
1. They set the minimum age for a learner’s permit at 16.
2. There’s a mandatory minimum waiting period between getting a learner’s permit and being able to apply for a license-usually six months.
3. Supervised driving requirements in the 50 to 100-hour range work best.
4. They set the minimum age for a provisional license at 17.
5. They include restrictions on night driving.
6. Restrictions also extend to the number of teenage passengers allowed in the car with a teenage driver.
7. They all share a minimum age of 18 for a full, unrestricted driver’s license.
What to expect moving forward
Laws in the United States typically change slowly, as shown by the 15-year timeframe for the full national adoption of graduated driver’s licenses. That means that future changes will likely be designed to support the law by moving individual states’ programs closer to the best practices revealed by the research. Unless some major change in licensing revolutionizes the process again, those changes are likely to remain small for the foreseeable future.