Estimating young novice drivers' compliance with graduated driver licensing restrictions: A novel approach

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.

Novice drivers and parents: exploring the feasibility of third-party policing in reducing young driver offending

“…This is supported by research conducted in the United Kingdom, which indicates that those young drivers who commit ordinary violations such as speeding and close following in the first few months of their solo driving career were more likely to continue to commit these types of offences in higher numbers as they continued to drive for the first three years (Roman, Poulter, Barker, McKenna & Rowe, 2015). In New Jersey, USA, approximately 8 per cent of intermediate drivers were not compliant with passenger restrictions (Curry, 2017) and approximately three per cent were not compliant with night driving restriction (Curry, Pfeiffer & Elliott, 2017).…”

Compliance With and Enforcement of Graduated Driver Licensing Restrictions

“…These studies have provided mostly high-level per-driver estimates, which have varied widely by jurisdiction and for several reasons may overestimate the true extent of non-compliance. 6,26 For example, a survey conducted in 2012 found that approximately 45% of NJ intermediate drivers reported driving with more than one passenger other than a family member. 27 Conversely, the QIE and naturalistic methods both estimate trip-level instead of driver-level compliance.…”

Young Driver Compliance With Graduated Driver Licensing Restrictions Before and After Implementation of a Decal Provision

“…18 In a series of previous papers, we demonstrated that this assumption is valid for the population of young intermediate drivers in NJ and that compliance with passenger and nighttime restrictions can be estimated using the QIE method. 11,14,19 Using these previously established methods, we identified all non-responsible 17-to 20-year-old intermediate drivers who were involved in a clean crash involving at least two vehicles from May 1, 2008 through April 30, 2012. For each study month, the prevalence of trip-level noncompliance was estimated as I i / N , where i is the restriction of interest, N is the total number of non-responsible intermediate drivers involved in clean multi-vehicle crashes, and I i is the number of these non-responsible intermediate drivers who were not in compliance with restriction i at the time of their crash.…”

“…12 However, surveys likely overestimate the true extent of young road users’ noncompliance as they reduce what is theoretically a continuous measure—the proportion of miles or trips in which a driver did not comply—into a categorical (e.g., ever: yes/no) or ordinal (e.g., how often: Likert scale) variable. 14 Additionally, low response rates may have limited representativeness and generalizability. Finally, the study reported that drivers’ awareness of the new GDL requirements increased in the post-decal period, increasing the potential that response-shift bias may have influenced pre-post survey compliance estimates.…”