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 |
|---|---|---|---|---|
| 182 | 1999/ 03 |
EVALUATION OF THE CLASS C DRIVER LICENSE WRITTEN KNOWLEDGE TESTSThis report presents the results of an evaluation of the English DL 5 (Rev. 10/98), Spanish DL 5 (Rev. 5/98), and English DL 5T (Rev. 8/98) Class C license written knowledge examinations. Specifically, 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 test form for the English tests. Also presented is an assessment of the randomness of the answer choice assignment for the English DL 5. |
II | |
| 221 | 2006/ 12 |
Evaluation of the Class C Driver License Written Knowledge TestsThis 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. |
II | |
| 157 | 1995/ 12 |
Evaluation of Mature Driver Improvement Program Home-StudyCoursesThis report compares the effectiveness of home-study and in-person courses offered underCalifornia's mature driver improvement (MDI) program. The major issue addressed inthe report is whether home-study MDI courses are less effective than in-person courses inreducing fatal/injury crashes and total citations. Two secondary issues are (a) the validityof MDI course completion as an indicator of fatal/injury crash risk and (b) whether MDIcourses themselves reduced fatal/injury crash risk. The study results provide littleevidence that home-study courses are less effective than in-person courses in reducingfatal/injury crashes and total citations, and no evidence that MDI course graduates are atactuarially lower fatal/injury crash risk than are nonparticipants. In addition, the resultsindicate that the MDI program may have reduced the rate of traffic violation citations,but not the rate of fatal/injury crashes, among course graduates. |
I | |
| 249 | 2014/ 10 |
Evaluation of Law Enforcement Use of Driver License Card Readers to Improve Detection of Suspended and Revoked Drivers at DUI/License CheckpointsIntroduction. Driving privilege suspension and revocation are known to improve traffic safety, but research suggests the majority of suspended or revoked (SR) drivers continue to drive while they are SR. These drivers are about three times more likely to be involved in crashes and to cause a fatal crash. In most U.S. states, drivers arrested for driving under the influence of alcohol or drugs (DUI) are subject to immediate driver license (DL) card confiscation by law enforcement. Drivers SR for other reasons are typically mailed notices directing them to surrender their DL cards to the licensing agency, yet they frequently do not comply. At DUI checkpoints in California, and many other U.S. states, law enforcement officers briefly inspect drivers’ DL cards and check for signs of intoxication. Hence, such checkpoints are deemed DUI/License status checkpoints. Previous research found that about 41% of SR drivers contacted at such checkpoints avoided detection for SR driving because they illegally retained possession of their DL cards. In this study, DL card readers with the capacity to identify and alert officers to drivers with SR statuses were used at the checkpoints. The purpose was to evaluate the utility of implementing this type of technology on a broader scale. Method. Checkpoint police officers used DL card readers that contained lists of SR drivers that would alert if a card was scanned that matched a DL number on the list. Data for 13,530 drivers were recorded. Subsequently, license statuses of contacted drivers were verified and compared to checkpoint citation records. Results. About 3% (n=384) of drivers contacted at the checkpoints were SR. Seventy-one percent of them were detected and cited for driving while SR. There were no differences in detection rate as a function of the suspension/revocation reasons. Significant differences were found in detection rate as a function of whether drivers’ DL numbers were on the SR list. Conclusion. SR drivers’ ability to pass undetected through DUI/License checkpoints weakens both the specific and general SR driving deterrence of checkpoints, and may diminish the effectiveness of suspension and revocation for reducing the crash risk posed by problem drivers. These findings show that despite technical limitations, a list-based DL card reader can improve the detection rate of SR drivers by law enforcement. Future studies that evaluate scanning technologies capable of real-time license validity verification are warranted. |
V | |
| NRN010 | 1986/ 12 |
Evaluation of Driver License Knowledge TestsTo pilot-test four of the Department's written knowledge examinations for driver licensure and provide test and item statistics. |
II | |
| 160 | 1995/ 09 |
Evaluation of California’s Special Drive Test ProgramThis 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. |
II | |
| 205 | 2003/ 05 |
Evaluation of California’s Graduated Driver Licensing ProgramCalifornia’s 1998 graduated driver licensing program was implemented to reduce the high crash risk of teenage drivers. Monthly per capita crash rates for 15-to-17-year-olds were analyzed using time series analysis. No overall reduction in total crashes or fatal/injury crashes was found immediately following program implementation or beginning 6 months later. The 12-month nighttime restriction was associated with significant sudden-permanent reductions of 0.44% in total crashes and marginally significant 0.45%in nighttime fatal/injury crashes. The 6-month passenger restriction was associated with reductions of 2.52% and 6.43% in total and fatal/injury teen passenger crashes, respectively. The fact that no overall reductions in crashes, and only small reductions in crashes associated with the restrictions, were found isnot surprising given findings that teens and parents were either already practicing program requirementsprior to implementation, or not fully complying with the program requirements afterwards. The findings provide support for passenger and nighttime restrictions. |
II | |
| 148 | 1995/ 03 |
EVALUATION OF CALIFORNIA’S COMMERCIAL DRIVER LICENSE PROGRAMThis 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. |
II | |
| NRN008 | 1983/ 07 |
Evaluation of Ambulance Driver Knowledge TestTo evaluate the Ambulance Driver Examination (DL-5J) and to provide test and item statistics. |
II | |
| 241 | 2013/ 02 |
EVALUATION OF A CONTACT LETTER TO INCREASE LICENSURE AMONG IMPROPERLY LICENSED CALIFORNIA MOTORCYCLE OWNERSThis report presents results of an evaluation of a pilot program intended to increase licensure among improperly licensed California motorcycle owners. The intervention used in this pilot program involved mailing an official DMV contact letter to owners of currently-registered motorcycles who were not properly licensed to ride two-wheeled vehicles. This correspondence informed the recipient of the legal consequences of riding without proper licensure, and provided information regarding how to obtain a motorcycle license in California. Half of the improperly licensed motorcycle owners (n = 33,068) were randomly assigned to be mailed the contact letter. The remainder (n = 32,698) served as a noletter control group. The 33-month subsequent-to-mailing license status and 18-month subsequent-to-mailing driver records for participants in these two groups were compared to determine the effect of the letter on motorcycle licensure, crashes, and violations. The results indicate that the contact letter increased motorcycle licensure among most age groups of owners, but did not affect crash involvements or traffic violations. The contact letter increased the number of previously unlicensed owners who became legal motorcycle operators without increasing their crash or traffic violation rates, but at a total net cost of $25.81 per additional owner who became properly licensed as a result of sending the letters. While the letter treatment significantly increased the motorcycle licensure rate, the overwhelming majority of treated owners in the present study (85.5%) remained improperly licensed to operate two-wheeled vehicles on public roadways, which is consistent with the results from a similar study in Maryland (Braver et al., 2007). Given the relatively low cost of treatment, the increase in motorcycle licensure associated with the letter, and the traffic-safety neutral outcomes, it is recommended that future use of a contact letter for improperly licensed owners be considered if the value of bringing owners into legal licensing status is deemed to be worth the cost of treatment. Future letters may be more effective if they are specifically tailored to the demographic characteristics (e.g., age and sex) of the unlicensed owners. |
VI |