Research Studies & Reports

DMV’s Research & Development Branch has been conducting research and producing studies and reports since the 1950s. Research & Development reports help DMV to measure the impact of new laws on making drivers safer. We also identify areas where we can improve our processes, explore new approaches to solving existing problems, and branch out into new opportunities to serve you better. 

Request printed copies of studies and reports by mail at:

Department of Motor Vehicles
Research and Development Branch
2415 1st Ave. Mail Station: F-126
Sacramento, CA 95818
(916) 914-8125

Please include the report number, the number of copies requested, and your name, address, and phone number.

393 Results

Report ID Date Published Title Section Links
160 1995/ 09

Evaluation of California’s Special Drive Test Program

By: Robert A. Hagge

This report presents results of an evaluation of the department’s special drive test (SDT) program. A totalof 407 forms used to refer drivers for an SDT and to score their performance on the test were collectedover a 2-week period in October 1993 from 82 field locations. The driver records for these subjects werealso analyzed. The results showed that the SDT had a fail rate of 31.1% and an internal-consistencyreliability of .88. The vast majority (3/4) of SDT referrals were not recommended for a license restriction(e.g., no night driving), although 96% of SDT fails were under license suspension or revocation sometimeduring the 6 months following SDT testing. The driver record analysis revealed that the 3-year prior totalaccident rate for SDT subjects was 3 times higher than that for drivers of the same age and sex in thegeneral driving population. For 3-year prior total citations, the rate for SDT subjects was nearly twice ashigh as the standardized rate for other drivers. The 3-year prior accident rate for SDT fails was notsignificantly different from that for SDT passes, but SDT fails had a significantly lower 3-year prior totalcitation rate than did SDT passes.It was concluded that (1) available treatments (e.g., license restrictions) for incompetent drivers referredfor an SDT are underutilized, (2) the SDT is not effective in discriminating between low- and high-riskdrivers, and (3) the SDT program appears to reduce accident risk for drivers who fail the test but not forthose who pass. It was recommended that a unified policy directive be developed that would address theobjective of the SDT and specify the criteria to be used for referring applicants for an SDT, scoring thetest, and translating test performance into a licensing decision.

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154 1995/ 08

An Evaluation of the Validity of California’s Driving PerformanceEvaluation Road Test

By: Patricia A. Romanowicz and Robert A. Hagge

This report presents findings of an evaluation of the validity of the Driving Performance Evaluation(DPE) road test that was piloted in 30 California Department of Motor Vehicles field offices. Thestudy represents the fourth stage in a four-stage project to develop an improved competency-baseddrive test for possible statewide implementation. The DPE was found to have construct validity asdemonstrated by experienced good drivers having had significantly lower fail rates and mean pointscores than did inexperienced drivers and drivers with physical or mental disabilities that affected theirdriving. The evaluation also found the DPE to be more difficult than the current drive test, with failrates of 45.6% and 26.2% for the two tests, respectively. The DPE was also found to take 11 minuteslonger to administer than did the current drive test. The impact on test validity of severalmodifications to shorten the DPE test time was also evaluated.

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155 1995/ 08

California’s Negligent Operator Treatment Program Evaluation System, 1976-1995 (An Overview of Findings and Program Improvements)

By: Raymond C. Peck and Erin J. Healey

This report represents a chronological review of an evaluation system which was initiated in the early 1970's and which was terminated at the end of 1994. Originally known as the Post Licensing Control Reporting and Evaluation System (PLCRES ) and later as the Negligent Operator Treatment Evaluation System (NOTES), it produced a large number of evaluation reports over the period 1976-1995. In 1982, departmental research staff received the National Highway Traffic Safety Administration's Award of Honor in recognition of the contributions of PLCRES reports to evaluation research literature.

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152 1995/ 06

Vision Testing of Renewal Applicants: Crashes Predicted when Compensation for Impairment is Inadequate

By: David F. Hennessy

This study addresses the enhanced vision test system component of a departmental plan to increase the competency level of the California driving population. Five experimental vision tests were administered to 3,669 randomly selected Class C renewal applicants in three field offices. The objective was to identify the vision tests showing the most promise for further validation in a large-scale statewide study. Hierarchical multiple regression analyses indicated that the relationship between vision test scores and crash involvement varies depending on applicant's age, general visual ability, and reported level of self-restriction. It was recommended that (1) management consider referring all DMV Snellen test fails to a vision specialist through the DL 62 process, (2) cross-validate the most promising tests (Pelli-Robson low-contrast acuity and perceptual reaction time assessment) in a large-scale demonstration project, and (3) continue research on developing improved assessment tests and protocols for drivers with age-related impairments.

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149 1995/ 05

An Evaluation of California’s Commercial Driver License Drive Test

By: Nancy Clarke

The federal government requires states which permit third-party testing of commercial drivers to determine whether these tests are equivalent to those given by the state driver licensing authority. To meet this requirement, the California Department of Motor Vehicles (DMV) plans to sample commercial driver license (CDL) applicants tested by their employer, retest them at DMV, and compare the fail rates for the employer and DMV tests to determine if they are equivalent in difficulty and reliability. In order to make this determination, it is necessary to estimate the reliability and other psychometric properties of the California DMV CDL test. Without this information, it is not possible to determine whether differences between the DMV and employer test exceed what would be expected from repeat administration of the CDL test by DMV.

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153 1995/ 05

NEGLIGENT-OPERATOR TREATMENT EVALUATION SYSTEM

By: William C. Marsh and Erin J. Healey

This report is the last in a series which originally began with the creation of the Post Licensing Control Reporting and Evaluation System (PLCRES) in 1976 and extended in 1983 by a modified version of that system (Negligent Operator Treatment Evaluation System). The present report is being issued as an internal technical report of the Department of Motor Vehicles' Research and Development Section rather than an official report of the State of California. The findings and opinions may therefore not represent the views and policies of the State of California.

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166 1995/ 05

Exploratory Multivariable Analyses ofCalifornia DriverRecord Accident Rates

By: Michael A. Gebers

Since 1964, the California Department of Motor Vehicles has issued several monographs on driver characteristics and accident risk factors as part of a series of analyses known as the California Driver Record Study. This paper presents the results of a number of regression analyses of driving record variables measured over a 6-year time period (1986-91). The techniques presented consist of ordinary least squares, weighted least squares, Poisson, negative binomial, linear probability, and logistic regression models. T he objective of the analyses was to compare the results obtained from several different regression techniques under consideration for use in the in-progress California Driver Record Study. The results are informative in determining whether the various regression methods produce similar results for different sample sizes and to explore whether reliance on ordinary least squares techniques in past California Driver Record Study analyses have produced biased significance levels and parameter estimates. The results indicate that, for these data, the use of the different regression techniques do not lead to any greater increase in individual accident prediction beyond that obtained through application of ordinary least squares regression. In addition, the methods produce almost identical results in terms of the relative importance and statistical significance of the independent variables. It therefore appears safe to employ ordinary least squares multiple regression techniques on driver accident-count distributions of the type represented by California driver records, at least when the sample sizes are large.

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148 1995/ 03

EVALUATION OF CALIFORNIA’S COMMERCIAL DRIVER LICENSE PROGRAM

By: Robert A. Hagge and Patricia A. Romanowicz

This report evaluates the impact of the Commercial Driver License (CDL) program on fataland fatal/injury accidents involving heavy vehicles operated by drivers licensed in California.The program, which was initiated in January 1985, began a new commercial-licenseclassification and endorsement system, implemented stronger licensing standards and morecomprehensive tests of knowledge and driving competency, required drivers to report specificviolations to employers, and provided for more stringent post-licensing sanctions to negligentoperators. Intervention time series analysis was used for data analysis. The results indicatethat the CDL program did not have a statistically significant effect on the fatal or fatal/injuryaccident series.

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147 1995/ 02

Knowledge and Attitude Change and the Relationship to Driving Performance Among Drivers Attending California Traffic Violator School.

By: Michael A. Gebers

One of the primary goals of the traffic violator school (TVS) program is to improve knowledge and attitudes toward traffic safety issues among drivers cited for traffic violations. While the TVS curriculum is standard for all courses, the courses may differ in content emphasis and other factors. Among the specific characteristics on which TVS programs differ are comedy versus non-comedy presentation modes, public versus private ownership, and use of advertising inducements. The present study examined how these d ifferences may influence t he amount of learning and attitude change resulting from TVS attendance. The results indicate that the amount of improvement in knowledge and positive attitude was not significantly related to method of instruction, type of provider, or use of an inducement to attract enrollees. No significant relationship was found between knowledge gain and s ubsequent accident involvement, or between attitude change and subsequent driver record entries. It was also found that although level of knowledge gain was associated with fewer subsequent traffic citations, the magnitude of the relationship was small. It was recommended that, to the extent that one of the goals of TVS is to increase knowledge of safe driving practices, there may be some value in requiring an exit test as a condition for receiving a TVS-completion certificate. However, there is no evidence at this time to conclude that such an increase in knowledge would result in a reduction in subsequent accident involvements.

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NRN038 1995/ 02

Driver License Strategies for Controlling the Persistent DUI Offender

By: Raymond C. Peck, J. Wilson & L. Sutton

To develop improved methods of identifying and controlling "hard core" Dill offenders through driver licensing.

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