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
226 2008/ 04

Evaluation of the Spanish Class C Driver License Written Knowledge Tests

By: Sukhvir S. Brar

This report presents the results of an evaluation of the Spanish language written knowledge tests completed by applicants for an original or renewal Class C driver license. The report presents the test fail rate, mean number of errors, and internal‐consistency reliability for each test form, as well as the pass rate, item choice selection rates, and item‐total correlation for each question on each form. Items that need to be reviewed for possible rewording or replacement are identified. The results are based on 4,539 completed test forms collected from all California Department of Motor Vehicle field offices from July 9 through 13, 2007.

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225 2008/ 03

Statewide Evaluation of Commercial Drivers License Written Knowledge Tests

By: Chyan V. Wu and Sukhvir S. Brar

This report presents the results of an evaluation of the written knowledge tests administered to applicants for a commercial driver license or endorsement. The report presents the fail rate, mean number of errors, and internal‐consistency reliability coefficient for each test form, as well as the pass rate, item‐choice selection rates, and item‐total correlation for each test question on each test form. Items that need to be reviewed for possible rewording or replacement are identified. Additional recommendations for improving the testing process are also provided. The results are based on 8,576 test sheets completed in all California Department of Motor Vehicle field offices from November 27, 2007 to December 31, 2007.

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224 2008/ 01

2008 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEM

By: Helen N. Tashima and Sladjana Oulad Daoud

In this seventeenth annual legislatively-mandated report, 2005 and 2006 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 cross tabulated information on DUI arrests, convictions, court sanctions, administrative actions and alcohol-involved crashes. In addition, this report provides 1-year proportions of DUI recidivism and crash rates for first and second DUI offenders arrested in each year over a time period of sixteen years. Also, the longterm recidivism curves of the cumulative proportions of DUI reoffenses are shown for all DUI offenders arrested in 1994. Analyses were conducted on the effectiveness of alcohol education programs upon the 1-year postconviction 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 postconviction records of first offenders. Two additional subanalyses were conducted to determine if differences on the outcome measures were related to BAC level (below 0.20% and 0.20% and above). The proportions of 2005 convicted first and second offenders who were referred to alcohol education/treatment programs are also presented.

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223 2007/ 04

A Traffic Safety Evaluation of California’s Traffic Violator School Citation Dismissal Policy

By: Michael A. Gebers

This study applied methodological refinements to the 1991 departmental evaluation of the traffic violator school (TVS) citation dismissal policy. This study identified and compared two large samples of drivers either completing a TVS (N = 210,015) or convicted of a traffic citation (N = 168,563). Prior to adjudication, the TVS group had characteristics (e.g., lower prior conviction rate and smaller proportion of males) that were predictive of a lower subsequent crash risk. However, the TVS group exhibited significantly more crashes than did the convicted group in the subsequent one-year period. The difference (4.83%) increased to 10% after adjusting for the more favorable characteristics of the TVS group. The TVS group also had a higher adjusted subsequent crash rate at each prior driver record entry level, reflecting a loss in the general and specific deterrence of the non-conviction masked status of TVS dismissed citations. It was also demonstrated that approximately 15,000 Negligent Operator Treatment System (NOTS) Level 3 (probation/suspension hearings) and 6,000 NOTS Level 4 (probation violator sanctions) interventions are circumvented annually because of TVS dismissals. The demonstrated effectiveness of the NOTS interventions in reducing crash risk of treated drivers assists in explaining why the driving public is exposed to an increased crash risk as a result of their avoidance. A number of recommendations are offered to reduce the negative traffic safety impact of the TVS citation dismissal policy.

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222 2007/ 01

2007 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEM

By: Helen N. Tashima and Sladjana Oulad Daoud

In this sixteenth annual legislatively-mandated report, 2004 and 2005 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 alcohol-involved crashes. In addition, this report provides 1-year proportions of DUI recidivism and crash rates for first and second DUI offenders arrested in each year over a time period of fifteen years. Also, the long-term recidivism curves of the cumulative proportions of DUI reoffenses are shown for all DUI offenders arrested in 1994. Analyses were conducted on the effectiveness of alcohol education programs upon the 1-year postconviction 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 postconviction records of first offenders. Two additional subanalyses were conducted to determine if differences on the outcome measures were related to BAC level (below .20 and .20 and above). The proportions of 2004 convicted first and second offenders who completed their alcohol education/treatment program requirement are also presented.

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221 2006/ 12

Evaluation of the Class C Driver License Written Knowledge Tests

By: Thomas W. Reiner and Robert A. Hagge

This report represents the results of an evaluation of English and Spanish language written knowledge tests that were administered to applicants for an original or renewal Class C driver license. The report presents test fail rates for multiple attempts, mean error scores, and internal consistency validity for each test form, as well as the pass rate, item‐choice selection rates, and item‐total correlation for each item on each English test form. Items that need to be reviewed for possible rewording or replacement are identified. The results are based on 11,307 completed test forms collected from all California Department of Motor Vehicle field offices on August 4, 2005, or for a few offices on a subsequent Thursday.

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220 2006/ 01

2006 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEM

By: Helen N. Tashima and Sladjana Oulad Daoud

In this fifteenth annual legislatively mandated report, 2003 and 2004 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 alcohol-involved crashes. In addition, this report provides 1-year proportions of DUI recidivism and crash rates for first and second DUI offenders arrested in each year over a time period of fourteen years. Also, the long- term recidivism curves of the cumulative proportions of DUI reoffenses are shown for all DUI offenders arrested in 1994. Analyses were conducted on the effectiveness of alcohol education programs upon the 1-year postconviction 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 postconviction records of first offenders. Two additional subanalyses were conducted to determine if differences on the outcome measures were related to BAC level (below .20 and .20 and above). The proportions of 2003 convicted first and second offenders who completed their alcohol education/treatment program requirement are also presented.

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218 2005/ 11

Development of a Driver License Application Management Information System Stage II

By: Eric A. Chapman

This project involved creating a prototype off-line driver license (DL) application management information system (MIS) that captured and stored extensive information on the driver license application process. From this prototype database, example reports were generated to demonstrate the feasibility of constructing a fully functional off-line DL application MIS that would be able to provide descriptive measures and statistical data related to the driver licensing process. In the event that Department of Motor Vehicles’ management decides to proceed with the creation of the proposed database, funding from the California Office of Traffic Safety would be requested for the next stage, Stage III, of the project. The implementation schedule for Stage III is provided in this report. Specifically, Stage III will involve addressing and correcting problems with the application transaction source data that were identified in this report and constructing a fully functional DL application MIS.

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197 2005/ 09

DUI COUNTERMEASURES IN CALIFORNIA: WHAT WORKS AND WHAT DOESN’T, WITH RECOMMENDATIONS FOR LEGISLATIVE REFORM

By: Clifford J. Helander

In 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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217 2005/ 09

AN EVALUATION OF THE EFFECTIVENESS OF IGNITION INTERLOCK IN CALIFORNIA

By: David J. DeYoung, Helen N. Tashima, and Scott V. Masten

This study is one of two studies of ignition interlock in California mandated by the California Legislature (AB 762). The first study, published in 2002, was a process evaluation that examined the degree to which ignition interlock has been implemented in California. This current study is an outcome evaluation that examines the effectiveness of ignition interlock in reducing alcohol-related crashes and convictions, and crashes overall (alcohol and nonalcohol). The results of the study show that interlock works for some offenders in some contexts, but not for all offenders in all situations. More specifically, ignition interlock devices work best when they are installed, although there is also some evidence that judicial orders to install an interlock are effective for repeat DUI offenders, even when not all offenders comply and install a device. California’s administrative program, where repeat DUI offenders install an interlock device in order to obtain restricted driving privileges, is also associated with reductions in subsequent DUI incidents. One group for whom ignition interlock orders do not appear effective is first DUI offenders with high blood alcohol levels.

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