Citation

Curry AE. Traffic Injury Prev. 2017; 18(1): 35-40.

Affiliation

Center for Clinical Epidemiology and Biostatistics Perelman School of Medicine at the University of Pennsylvania 423 Guardian Drive Philadelphia , PA 19104 USA.

Copyright

(Copyright © 2017, Informa - Taylor and Francis Group)

DOI

10.1080/15389588.2016.1171857

PMID

27064815

Abstract

OBJECTIVE: Current methods of estimating compliance with Graduated Driver Licensing (GDL) restrictions among young drivers with intermediate driver's licenses-which include surveys, direct observations, and naturalistic studies-cannot sufficiently answer many critical foundational questions: What is the extent of non-compliance among the population of young intermediate drivers? How does compliance change over the course of licensure? How does compliance differ by driver subgroup and in certain driving environments? This paper proposes an alternative and complementary approach to estimating population-level compliance with GDL nighttime and passenger restrictions via application of the quasi-induced exposure (QIE) method.

METHODS: The paper summarizes the main limitations of previous methods employed to estimate compliance. It then introduces the proposed method of borrowing the fundamental assumption of the QIE method-that young intermediate drivers who are non-responsible in clean (i.e., one and only one responsible driver) multi-vehicle crashes are reasonably representative of young intermediate drivers on the road-to estimate population-based compliance. I describe formative work that has been done to ensure this method can be validly applied among young intermediate drivers and provide a practical application of this method: an estimate of compliance with New Jersey's passenger restrictions among 8,006 non-responsible 17- to 20-year-old intermediate drivers involved in clean two-vehicle crashes from July 2010 through June 2012.

RESULTS: Over the study period, an estimated 8.4% (95% CI: 7.8%, 9.0%) of intermediate drivers' trips were not in compliance with NJ's GDL passenger restriction. These findings were remarkably similar to previous estimates from more resource-intensive naturalistic studies (Goodwin et al., 2006; Klauer et al., 2011 ).

CONCLUSION: Studies can practically apply proposed methods to estimate population-level compliance with GDL passenger and night restrictions; examine how compliance varies by relevant driver, vehicle, and environmental factors; and evaluate the implementation of a GDL provision or other intervention aimed at increasing compliance with these restrictions. Important considerations and potential limitations and challenges are discussed.

Language: en