The association of graduated driver licensing with miles driven and fatal crash rates per miles driven among adolescents

Abstract

Background Graduated driver licensing (GDL) laws are associated with reduced crash rates per person-year among adolescents. It is unknown whether adolescents crash less per miles driven or drive less under GDL policies. Methods We used data from the US National Household Travel Survey and Fatality Analysis Reporting System for 1995–1996, 2001–2002, and 2008–2009. We compared adolescents subject to GDL laws with those not, by estimating adjusted incidence rate ratios for being a driver in a crash with a death per person-year (aIRRpy) and per miles driven (aIRRm), and adjusted miles driven ratios (aMR) controlling for changes in rates over time. Results Comparing persons subject to GDL policies with those not, 16-year-olds had fewer fatal crashes per person-year (aIRRpy 0.63, 95% confidence interval [CI] 0.47, 0.91), drove fewer miles (aMR 0.79, 95% CI 0.63, 0.98), and had lower crash rates per miles driven (aIRRm 0.83, 95% CI 0.65, 1.06). For age 17, the aIRRpy was 0.83 (95% CI 0.60, 1.17), the aMR 0.80 (95% CI 0.63, 1.03), and the aIRRm 1.03 (95% CI 0.80, 1.35). For age 18, the aIRRpy was 0.93 (95% CI 0.72, 1.19), the aMR 0.92 (95% CI 0.77, 1.09), and the aIRRm 1.01 (95% CI 0.84, 1.23). Conclusions If these associations are causal, GDL laws reduced crashes per person-year by about one-third among 16-year-olds; half the reduction was due to fewer crashes per miles driven and half to less driving. For ages 17 and 18, there was no evidence of reduced crash rates per miles driven.

Association of Graduated Driver Licensing With Driver, Non-Driver, and Total Fatalities Among Adolescents

“…Previous studies have also suggested heterogeneity between adolescents aged 16 and 17 years. 17,38 Adult supervision or restrictions on night driving and number of underage passengers, all of which should be most common among adolescents aged 16 years, but as adolescents become older and these restrictions are removed, the influence of GDL on 17-year-olds could be less. In addition, graduation from GDL is possible at age 17 years in most states, particularly if the adolescent takes a driver education course.…”

Cell phone use while driving laws and motor vehicle driver fatalities: differences in population subgroups and location

“…Seatbelt laws with primary enforcement for front seat passengers were binary coded as present/absent. Graduated drivers licensing (GDL), which places additional restrictions on young or inexperienced drivers, can modify youths’ driving behaviors [45]. GDL laws were binary coded by state-quarter-year as present/absent.…”

The association between graduated driver licensing laws and travel behaviors among adolescents: an analysis of US National Household Travel Surveys

“…From 2001–2002 to 2008–2009, the average number of annual trips and kilometers for drivers/passengers decreased for all three age groups (16, 17, 20–24). This might be linked with the economic recession and high unemployment during 2008–2009 [ 28 ]. By including persons aged 20–24 years in our model, and adjusting for temporal changes in crash rates over time among those covered and not covered by a GDL law in each teenage age group, we sought to control for non-GDL factors that influence travel over time [ 13 , 21 , 22 , 28 ].…”