Strong graduated licensing laws maximize benefits

March 31, 2015

It's been nearly two decades since graduated driver licensing (GDL) programs began to take hold in the U.S., and these novice driver laws have proved extremely successful in reducing fatal crashes among teenagers. Still, many laws could be better. At least 10 states could more than halve or nearly halve their rate of fatal crashes among 15-17 year-olds if they adopted the five strongest GDL provisions, IIHS estimates.

Separately, a new IIHS study of GDL laws shows that progress on enhancing the most effective provisions of GDL has slowed. In recent years, most revisions to young driver laws have addressed driver cellphone use and texting, while other provisions known to promote big safety benefits have seen little change.

Graduated licensing gradually introduces new teenage drivers to the driving task as they mature and develop on-the-road skills. The system has three stages: a supervised learner's period, an intermediate license (after passing a road test) that limits driving in high-risk situations except under supervision, and a license with full privileges.

An online calculator developed by IIHS and HLDI in 2012 shows individual states the safety gains they could achieve by adopting some or all of the most beneficial GDL provisions in effect today. Based on IIHS and HLDI research, the calculator shows the estimated fatal crash and collision claim rate reductions that a given state can achieve with any combination of specific law changes.

"The question lawmakers should be asking themselves is, have we done all that we can do to keep our youngest drivers safe on the road? In many cases, the answer is no," says Anne McCartt, the Institute's senior vice president for research and an author of the GDL law study.

The five key components of GDL included in the calculator are permit age, practice driving hours, license age (which might be raised as a result of a long holding period for a learner permit) and restrictions on night driving and teen passengers.

Since there is no nationwide GDL system, the laws vary among states. The current best practices are a minimum intermediate license age of 17 (New Jersey), a minimum permit age of 16 (Connecticut, Delaware, District of Columbia, Kentucky, New Jersey, New York, Pennsylvania, Massachusetts and Rhode Island), at least 70 supervised practice hours (Maine) and, during the intermediate stage, a night driving restriction starting at 8 p.m. or earlier (sunset in Idaho and 6 p.m. during Eastern Standard Time in South Carolina) and a ban on all teen passengers (15 states and D.C.).

Prior IIHS and HLDI research has shown that states with the strongest laws enjoy the biggest reductions in fatal crashes among 15-17-year-old drivers and the biggest reductions in collisions reported to insurers among 16-17-year-old drivers, compared with states with weak laws.

States with the most room to improve

When the Institute introduced its GDL calculator three years ago, it pointed to South Dakota and Iowa as two states that could sharply lower fatal crash rates among teen drivers. These are among the top 10 states that could see the biggest reductions if they adopted the toughest GDL provisions. South Dakota still leads the list.

If South Dakota adopted the strongest provisions across the board, the state could see a 63 percent reduction in teens' fatal crashes and a 38 percent reduction in collision claims. Iowa could realize a 55 percent reduction in fatal crashes and a 30 percent decline in collision claims among teens if it followed suit.

Neighboring North Dakota would benefit from an estimated 56 percent reduction in the fatal crash rate of teen drivers if it strengthened its GDL law to match the toughest laws in the nation. Montana could reduce teens' fatal crashes by 53 percent, Arkansas by 50 percent, Idaho by 49 percent, Mississippi by 48 percent, New Mexico by 47 percent, Kansas by 46 percent and South Carolina by 45 percent.

States don't have to adopt all of the toughest provisions to realize benefits. For example, Montana allows teens to obtain a learner permit at age 14½ and a license at age 15. If it were to boost its learner permit age to 15½ and its licensing age to 16, the state could achieve an estimated 26 percent reduction in fatal crashes and an estimated 8 percent reduction in collision claims among 15 to 17 year-olds.

A crucial GDL provision is a night driving restriction. Vermont is the only state that doesn't restrict novices from driving at night without an adult. Enacting an 8 p.m. restriction to match the strictest in the U.S. would reduce Vermont teens' fatal crashes by an estimated 20 percent.

Allowing beginning drivers to transport other teens without adult supervision raises their risk of crashing. Florida, Iowa, Mississippi, North Dakota and South Dakota don't impose any passenger restrictions on novice drivers. All five of these states could reduce fatal crashes among 15 to 17 year-olds by limiting teen passengers to one when an adult isn't riding along, and could reduce fatal crashes even more by barring all teen passengers.

Even New Jersey, whose licensing age of 17 is the highest in the nation, could improve its standing by replacing its one-passenger limit with a zero-passenger restriction. The move would reduce teen fatal crashes by an estimated 16 percent.

In addition, New Jersey could reduce fatal crashes by an estimated 4 percent and collision claims by an estimated 17 percent if it were to require 70 hours of supervised practice driving. New Jersey is one of eight states (along with Alabama, Arizona, Arkansas, Mississippi, Nebraska, South Dakota and West Virginia) without a requirement that beginners get a minimum number of supervised practice driving hours before progressing to an intermediate license.

This map shows how much each state could reduce the fatal crash rate for teens if it adopted the strongest policies in five GDL components. The states that would improve the most are shown in red.

GDL map

Toughest laws

  • Permit age of 16:
  • Connecticut
  • Delaware
  • D.C.
  • Kentucky
  • New Jersery
  • New York
  • Pennsylvania
  • Massachusetts
  • Rhode Island
  • 70 supervised practice hours:
  • Maine
  • Licensing age of 17
  • New Jersey
  • 8 p.m. night driving restriction
  • Idaho (sunset to sunrise)
  • South Carolina (6 p.m. EST)
  • No teen passengers:
  • Alaska
  • California
  • Colorado
  • Connecticut
  • D.C.
  • Georgia
  • Indiana
  • Maine
  • Maryland
  • Massachusetts
  • Nevada
  • Oregon
  • Utah
  • Vermont
  • Washington
  • West Virginia

Legislative progress since initial laws

Starting with Florida in 1996, states quickly began adopting elements of graduated licensing. Early law changes most often included a learner period usually lasting about six months. Nighttime driving restrictions were more common than teen passenger restrictions. Georgia implemented the first passenger limit in the U.S. in 1997, and that same year Michigan was first to require a minimum number of hours of supervised driving before obtaining an intermediate license.

Since the mid-1990s, all but seven states have strengthened their initial GDL requirements by adding or strengthening key features, such as lengthening the learner permit period or the duration of nighttime driving or passenger restrictions.

Between 1998 and 2010, an average of 11 upgrades to GDL laws were made each year. The busiest legislative year was 2005, when 18 laws were strengthened. The pace has slowed since 2010.

Only four states have adopted substantial upgrades to their teen driver laws since IIHS launched its GDL calculator in 2012. Three states increased the minimum number of supervised practice hours — from 35 to 70 in Maine, 30 to 40 in Minnesota and 20 to 30 in Texas. Iowa, meanwhile, increased the minimum learner permit holding period from 6 months to a year.

The reasons for the slowdown in GDL improvements aren't clear. Changes in the political composition of state legislatures may have played a role, and some lawmakers may be reluctant to tinker with long-established GDL systems.

Since the first GDL program was implemented in 1996, fatal crash rates have fallen more dramatically for teens than for adults.

Fatal crashes per 100,000 by driver age, 1996-2013

Quick spread of distracted driving laws

Another reason may be because policymakers have focused on distracted driving amid concerns about teens' widespread cellphone use and the fact that their immaturity and inexperience behind the wheel make them more susceptible to distractions of any kind.

"Enacting distracted driving laws for teens appears to be more palatable than enacting stricter GDL laws," McCartt says. "Only two states had a cellphone or texting ban for teenage drivers in 2004. Since then, 38 states and D.C. have implemented teen-specific bans. That's a remarkable pace."

Forty-eight states and D.C. have texting bans covering young drivers, 37 states and D.C. ban all cellphone use for young drivers, and three states ban hand-held cellphone use for young drivers. Additional states have hand-held cellphone bans covering drivers of all ages.

Few studies have examined the effects of cellphone and texting laws on crashes involving teenagers, and the evidence from these studies is mixed and inconclusive. Evaluations of North Carolina's law banning all cellphone use by teen drivers found no short-term or long-term decrease in use.

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