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 |
|---|---|---|---|---|
| 238 | 2012/ 09 |
ESTIMATION OF FATAL CRASH RATES FOR SUSPENDED/REVOKED AND UNLICENSED DRIVERS IN CALIFORNIAThis study used a quasi-induced exposure (QIE) analysis technique to estimate annual fatal crash involvement rates for S/R, unlicensed, and validly licensed drivers in California from 1987 through 2009 using fatal crash data obtained from National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS) and California Department of Highway Patrol’s Statewide Integrated Traffic Records System (SWITRS). The annual fatal crash involvement ratios range from 0.81 to 0.91 for validly licensed drivers, 1.44 to 4.29 for S/R drivers, and 1.60 to 3.50 for unlicensed drivers, respectively, over the 23-year time period studied. The annual at-fault overinvolvement rates for S/R and unlicensed drivers relative to validly licensed drivers range from 1.57 to 4.93 for the S/R group and from 1.84 to 4.10 for the unlicensed group. Although the annual rates fluctuate, S/R and unlicensed drivers were overinvolved as at-fault drivers in fatal crashes every year relative to validly licensed drivers. The fatal crash involvement ratios obtained for all years combined (1987 through 2009) are 0.86 for validly licensed drivers, 2.23 for S/R drivers, and 2.34 for unlicensed drivers. The at-fault overinvolvement rates for the S/R and unlicensed groups, relative to the validly licensed group, are 2.60 and 2.73, respectively, for this 23-year period. The study results provide strong evidence that S/R and unlicensed drivers are much more hazardous on the road than are validly licensed drivers. Compared to licensed drivers, those who drive without a valid license are nearly three times more likely to cause a fatal crash relative to their exposure. The study findings strongly justify the use of countermeasures, including vehicle impoundment, to control S/R and unlicensed drivers and to reduce crashes caused by these drivers. |
VI | |
| 237 | 2012/ 05 |
Identifying Barriers to Driving Privilege Reinstatement among California DUI OffendersEvidence suggests that many suspended DUI offenders delay reinstatement of their driving privileges long after they become eligible to reinstate and that those who delay have higher recidivism rates and remain outside of the driver-control system, making corrective action difficult if their driving continues to be a problem. This study updates prior estimates of the extent to which California DUI offenders delay reinstatement of their driving privileges after suspension and investigates the perceived barriers to reinstatement through surveys of offenders and DUI-system professionals. California driver records show that the majority of otherwise reinstatement-eligible 1st and 2ndDUI offenders in California do not reinstate their driving privileges 3 or more years following their arrests. The surveyed offenders and DUI-system professionals indicated strong agreement that high overall financial costs and offenders’ confusion about system requirements are the most significant barriers to meeting the obligations that would enable offenders to reinstate their driving privilege, followed closely by failure to complete DUI Program requirements, most often because of offenders’ inability to pay the program costs, and also because they lack available alternate transportation to attend classes. The barriers to reinstatement may effectivelydeter some offenders from driving, preventing DUI incidents they might otherwise have caused, but appear to deprive others at risk of recidivating who continue to drive impaired from access to needed intervention programs. To address the study’s primary identified barriers to driving privilege reinstatement, several recommendations are made addressing cost mitigation, improved centralized communication of system requirements, and the benefits to obtaining early license restrictionand, ultimately, reinstatement. |
III | |
| 236 | 2012/ 01 |
2012 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEMIn this twenty-first annual legislatively-mandated report, 2009 and 2010 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 20 years. Also, the long term recidivism curves of the cumulative proportions of DUI reoffenses are shown for all DUI offenders arrested in 1994. Two analyses were conducted to evaluate if referrals to DUI programs were associated with reductions in 1-year subsequent violations and crashes among those convicted of the reduced charge of alcohol-related reckless driving, and if referrals to the 9-month DUI program were associated with reductions in 1-year subsequent violations and crashes when compared to referrals to the 3-month DUI program among first DUI offenders. The proportions of convicted first and second DUI offenders arrested in 2009, who were referred, enrolled, and completed DUI programs are also presented. |
V | |
| 235 | 2012/ 01 |
An Evaluation of Factors Associated with Variation in DUI Conviction Rates Among California CountiesAlthough California’s statewide driving-under-the-influence of alcohol and/or drugs (DUI) conviction rate has improved over time from 64% in 1989 to 79% in 2006, the DUI conviction rates vary considerably among counties. The purpose of this study was to identify factors associated with differences among California county DUI conviction rates averaged from 2000-2006. The three approaches to obtain information were: (a) surveys sent to California judges, prosecuting attorneys, public and private defense attorneys, and court administrators; (b) face-to-face interviews conducted with California judges, prosecuting attorneys, and public and private defense attorneys; and (c) analyses of various county-level demographic and socioeconomic factors, DUI arrest and conviction process measures, and crash/recidivism variables. It was found that counties with higher DUI arrest rates tend to have lower DUI conviction rates. Counties with high DUI conviction rates tend to convict at lower BAC levels and have higher percentage usage of blood BAC tests. Counties also varied in their alcohol-reckless conviction rates as well as the BAC levels considered appropriate for negotiating alcohol-reckless plea bargains. While the 7-year (2000-2006) statewide average percentage of DUI arrestees convicted of alcohol-reckless driving was 8.1%, county percentages ranged from 0% to 22.6%. Higher prosecution caseload as measured by county violent crime rates isassociated with lower DUI conviction rates, while shorter lengths of time from arrest to conviction are associated with higher DUI conviction rates. Varying prosecution policies were strongly identified by survey respondents as influencing variation in county DUI conviction rates. Convicting for drug-only DUI was considered to be very difficult due to the lack of scientifically based per se levels of drug impairment. Recommendations are made based on these findings. |
III | |
| 234 | 2011/ 12 |
California’s Three-Tier Driving-Centered Assessment System – Outcome AnalysisThis Outcome Analysis constitutes the second of two reports on the 3-Tier Assessment System, as piloted by California DMV in 2006-2007. It contains (a) a projection of the costs associated with the Area Driving Performance Evaluation, (b) a determination of the willingness of a participant to pay a fee for the Area Driving Performance Evaluation, (c) a determination of the percentage of drivers who were assessed to have a limitation, but who, upon completion of the assessment, were able to retain their driving privileges, (d) the utilization of certified driving rehabilitation specialists, and (e) the results regarding crash rates and retention of driving privileges. Together, these analyses examine the effectiveness of the 3-Tier Assessment System in identifying functional impairments, reducing crashes, and extending safe driving years for California drivers of all ages. These analyses are based upon 2 years of elapsed driving history for the 12,279 customers who participated in the Pilot, along with two control groups: 14,907 customers in the Baseline II cohort, and 10,551 customers in the Nearby cohort. Based on limited data, an estimation is provided of the costs of the anticipated increase in the use of the ADPE, as associated with the 3-Tier Assessment System. Very few customers were willing to pay a fee for the ADPE. The overwhelming majority of customers, even those with functional limitations, were able to retain their driving privilege. No customers reported using certified driving rehabilitation specialists. The analyses found no evidence for a reduction in crash risk subsequent to participation in the Pilot; however, the analyses found some evidence that the Pilot is associated with an increased amount of time to complete the renewal process, with an increase in the odds of failing to renew the driving privilege, and with an increase in the odds of receiving a restricted license. Recommendations regarding implementation and future research are included. |
II | |
| 233 | 2011/ 01 |
2011 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEMIn this twentieth annual legislatively-mandated report, 2008 and 2009 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 19 years. Also, the long-term recidivism curves of the cumulative proportions of DUI reoffenses are shown for all DUI offenders arrested in 1994. Two analyses were conducted to evaluate if referrals to DUI programs were associated with reductions in 1-year subsequent violations and crashes among those convicted of the reduced charge of alcohol-related reckless driving, and if referrals to the 9-month DUI program were associated with reductions in 1-year subsequent violations and crashes when compared to referrals to the 3-month DUI program among first DUI offenders. The proportions of 2008 convicted first and second offenders who were referred, enrolled, and completed DUI programs are also presented. |
V | |
| 232 | 2010/ 04 |
California’s Three-Tier Driving-Centered Assessment System – Process AnalysisOn September 14, 2006, California Governor Arnold Schwarzenegger signed Assembly Bill 2542 (Daucher) into law, adding Section 1659.9 to the California Vehicle Code, and calling for a pilot study by the California Department of Motor Vehicles (CA DMV) of the 3-Tier Assessment System. This manuscript (the “process report”) constitutes the first of two reports on the 3-Tier Assessment System. It details the planning and implementation of the pilot, the process outcomes for the 12,346 CA DMV customers who participated in the pilot as well as the 4,853 customers who constituted a baseline comparison group, and the results of the subsequent multi-component process evaluation. The process evaluation includes a description of the costs to implement the pilot, discussion of various threats to the methodological validity of the process and outcome analyses, and an estimation of the potential costs of statewide implementation. An appendix to this report (published separately) contains more detailed analyses associated with four components of the process evaluation: the results of a survey of participating staff, the results of qualitative interviews conducted with participating staff, the results of a survey of pilot customers, and the results of an analysis of customer outcomes on the Pelli-Robson contrast sensitivity assessment. |
II | |
| 231 | 2010/ 01 |
2010 ANNUAL REPORT OF THE CALIFORNIA DUI MANAGEMENT INFORMATION SYSTEMIn this nineteenth annual legislatively-mandated report, 2007 and 2008 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 18 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 DUI programs in reducing 1-year subsequent violations and crashes of those convicted of the reduced charge of alcohol-related reckless driving, and on the effectiveness of the 3-month versus 9-month DUI programs for first offenders. Two additional subanalyses were conducted to determine if differences in the outcome measures were related to BAC level (below 0.20% and 0.20% and above). The proportions of 2007 convicted first and second offenders who were referred, enrolled, and completed DUI programs are also presented. |
V | |
| 230 | 2009/ 06 |
Enhanced Negligent Operator Treatment Evaluation System Program Effectiveness Report #1 (Summary Of Findings)The Enhanced Negligent Operator Treatment Evaluation System (ENOTES) provides periodic cost-effectiveness analyses of the California Negligent Operator Treatment System (NOTS). The evaluation system is based on a comparison of the driving records of negligent operators (drivers with multiple traffic conviction and/or crash points) who are randomly assigned to an intervention or to a no-contact delayed treatment comparison group. Three levels of progressively more severe negligent operator interventions were evaluated in this manner; the fourth-level intervention (the most severe) was evaluated indirectly by using data from the Level 3 intervention. Drivers at Levels 1 and 2 were eligible to receive the standard, non-alcohol letter or a letter based on the Transtheoretical Model (TTM) of behavior change. The results found NOTS to be effective in reducing subsequent total crashes and citations of treated drivers. Consistent with prior evaluations of NOTS, the largest effects were found for the probation and probation violator sanctions, and the smallest effects were associated with the Level 1 and 2 letters. Within Levels 1 and 2, the TTM letters were found to be more effective than the standard letters in reducing subsequent traffic crashes and convictions. A cost effectiveness analysis of NOTS provided positive estimates at all four levels. |
III | |
| 229 | 2010/ 04 |
California’s 3‐Tier Pilot Process Analysis AppendixThis report presents the descriptive and predictive analyses of: (i) the results of a survey (n = 130) conducted of California Department of Motor Vehicles (CA DMV) Field Office and Driver Safety Branch staff and managers participating in the 3‐Tier Pilot project; (ii) interviews (n = 49) conducted of CA DMV Field Office and Driver Safety Branch staff and managers participating in the 3‐Tier Pilot; (iii) the results of a survey (n = 5,777) conducted of customers participating in the 3‐Tier Pilot; and (iv) the robustness of the Pelli‐Robson contrast sensitivity chart by location and technician (n = 9,934). These analyses form the primary evidentiary basis for some of the findings and conclusions presented in the 3‐Tier Pilot Process Analysis Report. |
II |