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.
Studies & Reports Sections
Studies and reports are assigned to a Section that best describes the type of report. Click on a section title below to see a short description.
I. Driver Education & Training Studies
II. Driver Licensing Screening Studies
III. Studies on Improvement and Control of Deviant Drivers
IV. Basic Research & Methodological Studies: Driver Performance, Accident Etiology, Prediction Models, and Actuarial Applications
V. Driver Licensing / Control Systems & Safety Management Studies
VI. Studies on Special Driver Populations
VII. Miscellaneous Studies & Reports
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.
| Report ID | Date Published | Title | Section | Links |
|---|---|---|---|---|
| 195 | 2002/ 05 |
AN EVALUATION OF THE IMPLEMENTATION OF IGNITION INTERLOCK IN CALIFORNIACalifornia law requires judges to sentence offenders convicted of driving on a DUI-suspended driver license (DWS-DUI) to install an ignition interlock device (IID) on any vehicle that they own or operate. In addition, repeat DUI offenders can reduce their suspension period by half and obtain a restricted license by installing an IID. This report presents the results of a process study of the degree to which California’s IID laws have been implemented. The process evaluation consists of several components. DWS-DUI and DUI offenders were tracked through law enforcement, DMV, court and ignition installer records to obtain data on rates of DWS convictions, court-IID orders, IID installations and offender success on the IID program. In addition, DMV records were utilized to obtain data on court-IID orders throughout the state, over time and jurisdictions. Finally, judges, district/city attorneys and offenders were surveyed to obtain data on barriers to the use of IIDs, and attitudes and opinions of the devices. The results of the process studies showed that DWS conviction rates were less than 20%, courtIID order rates for DWS-DUI convictees, for whom such an order is required by law, were only about 25%, and only a minority of offenders ordered to install a device complied and installed an interlock. In addition, relatively few repeat DUI offenders chose to obtain a restricted license by installing an IID. While some recommendations are made for improving the current IID countermeasure system, it is strongly recommended that the current IID laws remain unchanged until the r |
V | |
| 196 | 2005/ 05 |
Development and Evaluation of Revised Class C Driver LicenseWritten Knowledge TestsThis report presents the results of an evaluation of English and Spanish language Class C license written knowledge examinations administered to applicants for an original or renewal driver licenses. The tests were extensively modified following the 1999 statewide evaluation (Masten, 1999). The study assessed the fail rate, mean number of errors, and internal-consistency reliability for each test form, as well as the pass rate, percentage of applicants selecting each answer choice, and item-total correlation for each item on each English language test form. The results are based on 10,502 completed test forms that were collected from field offices statewide in April 2001. It was found that the test fail rates for all tests decreased from the last statewide evaluation. However, the disparity in fail rates between the English and Spanish tests increased, with the rates for Spanish applicants continuing to be substantially higher than the rates for English applicants. |
II | |
| 197 | 2005/ 09 |
DUI COUNTERMEASURES IN CALIFORNIA: WHAT WORKS AND WHAT DOESN’T, WITH RECOMMENDATIONS FOR LEGISLATIVE REFORMIn response to recent increases in driving-under-the-influence (DUI) crashes and fatalities in California, after years of decline, the California legislature (Senate Bill 776, Torlakson, 2001) mandated a review of scientific evidence on effective DUI countermeasures. As shown in this review, the following driver-based countermeasures have proven significantly effective in reducing alcohol-impaired driving: minimum drinking age laws, per se BAC laws, administrative per se license action laws, "Zero-tolerance" laws for youth, other licensing actions including restriction and probation, alcohol treatment, server intervention programs, house arrest in lieu of jail, lower per se BAC for repeat offenders, sobriety checkpoints, and public information and education. Effective vehicle-based countermeasures include vehicle impoundment, vehicle immobilization, and ignition interlock, while other countermeasures impacting alcohol-impaired driving include seat belts, graduated driver licensing, and alcoholic beverage control. Traditional DUI sanctions of fines and jail are shown to be among the least effective DUI countermeasures. Most importantly, there are four major initiatives which offer the potential for large-scale reductions in alcohol impaired driving, including new pharmaceutical treatments (naltrexone), increased alcoholic beverage control, reducing the contribution of on-premise drinking to the DUI problem, as well as prevention efforts focused on youth. There continues to be strong public support for anti-DUI efforts, including the raising of alcohol taxes, provided the funds are used against drunk driving. In general, prevention efforts, as opposed to further increased punishments, are seen as having a greater potential for future reductions in the incidence of DUI. |
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| 198 | 2003/ 01 |
2003 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEMIn this twelfth annual legislatively mandated report, 2000 and 2001 DUI data from diverse sources were compiled and cross-referenced for the purpose of developing a single comprehensive DUI data reference and monitoring system. This report presents crosstabulated information on DUI arrests, convictions, court sanctions, administrative actions and alcoholinvolved accidents. In addition, this report provides an evaluation of the effectiveness of alternative court and administrative sanctions (including alcohol treatment programs and license actions) upon the 1-year postconviction records of first and second DUI offenders over a time period of eleven years. The postconviction driving records of second DUI offenders arrested in 1998 and 2000 were evaluated for 3- and 1-year periods, respectively. Additional analyses were conducted on the effectiveness of alcohol education programs upon the 1-year post conviction records of those convicted of the reduced charge of alcohol-related reckless driving, and on the effectiveness of the 3-month versus 6-month alcohol education programs on the 1-year post conviction records of first offenders. |
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| 199 | 2002/ 11 |
Application of Behavior Change Theory to the Development of an Enhanced California Negligent Operator Treatment and Evaluation SystemThrough this critical review of the literature and evaluation of warning letter contents, the foundation has been set for the development of an enhanced negligent-operator treatment and evaluation system (ENOTES) for California. Criteria to evaluate the treatment letters were developed from the 16 components of the Transtheoretical Model (TTM) of behavior change that, incidentally, incorporates the majority of the recommendations made by traffic safety researchers over the past 50 years. The evaluated studies were tabulated by the strength of the evidence supporting each treatment in terms of the quality of the research and the validity of the methods as defined by the degree to which they reflected components of the TTM. Overall, the research designs were outstanding. However, the warning letters themselves were weaker, and generally not strongly tied to a theory of behavior change. On average, 2.5 of the six General Stage, 1.8 of the five Early Stage, and 0.29 of the five Late Stage TTM elements were utilized. No balanced treatment letters were identified that incorporated the majority of the TTM elements available from all three stages. A definite opportunity exists to strengthen the effectiveness of letter treatments through intelligent use of the TTM |
III | |
| 200 | 2002/ 11 |
An Examination of the Characteristics and Traffic Risk of Drivers Suspended/Revoked for Different ReasonsOne measure that has traditionally been used to better control drunk and other high-risk drivers has been to suspend or revoke their privilege to drive. However, because the driving privilege is so highly valued, an increasing number of new laws have been passed which prescribe license suspension/revocation as a punishment for a variety of offenses, including some completely unrelated to driving. This has created a diverse group of suspended/revoked drivers. Prior research has demonstrated that suspended/revoked drivers pose a significant traffic risk, but until now little has been known about whether, and if so how, this risk varies as a function of the reason for suspension/revocation. This study classifies suspended/revoked drivers into subgroups based on their reason for suspension/revocation, and then develops demographic and driving risk profiles for each group. Separate risk profiles are developed for the following traffic safety indicators, measured 3 years prior to the suspension/revocation action; 1) total crashes, 2) fatal/injury crashes, 3) total traffic convictions, and 4) total incidents (crashes + convictions). The findings clearly show that: 1) suspended/revoked drivers are a heterogeneous group, both demographically and in their driving behavior; 2) some suspended drivers, such as those suspended/revoked for a non-driving offense, have low traffic risks that are comparable to those of validlylicensed drivers, and; 3) all suspended groups have elevated crash and conviction rates, compared to validly-licensed drivers. The implications of these findings for current laws and policies targeting suspended/revoked drivers are discussed, and recommendations for improving these laws/policies are presented. |
IV | |
| 201 | 2003/ 01 |
Comparison of Accident and Conviction Rates for Commercial Drivers Tested Under the Employer Testing Program and Commercial Drivers Tested by DMVThe Employer Testing Program (ETP) allows eligible employers to conduct drive tests and issue the Certificate of Driving Skills (DL 170) to commercial vehicle operators they employ. To participate in the program, an employer must demonstrate that their driving test and examiners meet standards set by DMV. Employers in the program are subject to annual inspections and audits by the department’s Intrastate Audits Unit. If any deficiencies on the part of the employer are found, the department may impose restrictions ranging from warning letters to revocation or cancellation of the employer’s testing authorization. Approximately 980 employers participate in this program, 60% of which are in the government sector (e.g., fire departments and Caltrans). To help in monitoring the program, the department’s Research and Development Branch compared the driving records of licensed commercial drivers tested under the ETP to commercial drivers tested by DMV. The remainder of this paper presents the methods and results of the driver record analyses and a discussion of the findings. |
IV | |
| 202 | 2003/ 03 |
Development and Evaluation of a Risk Management Strategy for Reducing Crash RiskThe goal of this project was to develop a strategy for maximizing the number of traffic crashes prevented by tailoring educational, rehabilitative, and license control interventions to identifiable high-risk problem driver groups. Regression models were applied to a random sample of licensed California drivers with the objective of identifying groups of drivers with elevated risks of being involved in future traffic crashes. The driving records of the risk groups identified from the models were examined to identify drivers not receiving any form of driver improvement or license control actions. The risk levels of these identified "untreated" drivers were compared with negligent operators who have received licensing actions to determine how existing discretionary and mandatory actions correlate with traffic safety risk. The defining characteristics of high-risk drivers escaping driver improvement or license control actions were examined in an attempt to construct a recommended set of countermeasures. The potential utility of these countermeasures in terms of crash reduction and benefit-cost ratios was estimated based on prior research evidence and mathematical simulation. In examining the defining characteristics of high-risk groups that currently escape driver improvement interventions, the majority was characterized either by TVS dismissals, citations, or crashes. These elements often combine with each other and with other risk factors to increase crash risk beyond that of drivers who meet the state’s prima facie definition of a "negligent operator." It is noted that there are two fundamental considerations for constructing a countermeasure system: (1) the countermeasures must be economically and operationally feasible, and (2) they must be legally permissible. Therefore, this study recommends interventions involving minimal expense, no in-person contact with DMV personnel, and no license-control actions. |
IV | |
| 203 | 2003/ 04 |
The Effectiveness of Home-Study Driver Education Compared toClassroom Instruction: The Impact on Student Knowledge, Skills, andAttitudesHome-study driver education programs exist in several states, but none have been scientificallyevaluated to determine if such courses are as effective as classroom-based courses for teaching driver education. Almost 1,500 students were randomly assigned to receive classroom instruction, a CDROM home-study course, a workbook home-study course, or an internet/workbook home-studycourse. Few differences were found on exit exam knowledge and attitude scores, but tended to favor the CD and internet/workbook home-study courses over the workbook or classroom courses.Differences favoring classroom courses on department written test outcomes likely reflect bias in such courses towards teaching test-specific material. The findings present no compelling evidence that home-study courses are less effective than classroom courses for teaching driver education. Thefindings could result in more widespread use of home-study courses. The use of low-cost home-study courses as the first stage of a two-tiered driver education program could make such programs more feasible and acceptable to the public. |
I | |
| 204 | 2003/ 10 |
An Inventory of California Driver Accident Risk FactorsThis report updates information on a random sample of licensed California drivers as published in an earlier report prepared by the California Department of Motor Vehicles: An inventory of California driver accident risk factors (Gebers & Peck, 1994). It is designed to provide highway safety administrators, insurance industry representatives, and researchers in the field of traffic safety with information for developing program and policy decisions. This report presents driver record information on a random sample of over 200,000 California drivers and driver record histories over varying time periods. The report addresses the following issues related to the assessment of traffic accident risk: • Driver record in relation to gender and age. • Accident-repeater phenomenon. • Relationship between traffic accidents and citations. • Relationship between traffic accidents and multiple driver record variables (e.g., prior accidents and citations, sex, and license class). • Multiple logistic and negative binomial regression equations of accident risk factors and relativities. Findings presented in the report confirmed that prior total citation frequency continues to be the most significant predictor of accident involvement, followed by prior accident involvement frequency. Increased accident involvement was shown to be associated with increased prior citation and accident frequencies, possessing a commercial driver license, being young, being male, having a medical condition on record, and having a physician referral for low visual-acuity on record. |
IV |