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
2570 24th Street, Mail Station: H-126
Sacramento, CA 95818
(916) 657-5805

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

Report ID Title Section Links


By: Robert A.Hagge

In 1990 the California Department of Motor Vehicles (DMV) initiated a program to increase the level of driving competency of the California driver population. A key element of this program involves the development and implementation of an improved drivetest.



By: Nancy Clarke Shumaker

The California DMV is currently involved in a comprehensive effort to increase the competency level of the California driving population. One of these efforts involves the development of a new class C (passenger vehicle) drive test. The present report is designed to provide data on the reliability and psychometric properties of the current class C road test in order to provide a baseline comparison for the new drive test. This evaluation of the current test represents "Stage 1" in a multi-phase test development master plan (Williams & Shumaker, 1994).


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.


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.


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.



By: Scott V. Masten

The purpose of this study was to evaluate the English DL 5 (Rev. 3/96), Spanish DL 5 (Rev. 7/95), and English DL 5T (Rev. 3/96) driver written license tests. Specifically, the study assessed the fail rate, mean number of items missed, 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.



By: Scott V. Masten

The purpose of this study was to evaluate the redesigned DL 44 (Rev. 6/97) driver license application form. The Business Process Reengineering team revised the DL 44 to make it more user friendly, simplify the form’s language, and remove redundant or unneeded information. One of the changes was to combine the two vision and physical/mental (P/M) condition questions into a single question on the revised DL 44. The purpose of the current study was to assess whether the percentage of applicants self-reporting P/M conditions that could affect their ability to drive safely was reduced by combining the vision disorder and P/M condition questions into one question on the redesigned form.



By: Scott V. Masten

This report presents the results of a preliminary formative and process evaluation of the DPE referral drive test program. The purpose of the study was to develop descriptive measures of the Referral Driving Performance Evaluation (RDPE) process and, where possible, to determine whether the program guidelines are being followed, particularly the appropriate use of license restrictions and revocations following test failure.


Evaluation of the Referral Driving Performance EvaluationProgram—Follow-Up Report

By: Scott V. Masten

This study evaluated the safety impact of the new Referral Driving Performance Evaluation (RDPE) drivetest program. The 3-year prior accident and citation rates for drivers taking the RDPE drive tests werecompared to the general driving population and to drivers who passed the Special Drive Test (SDT) in anearlier DMV study. The results indicated that in every age and gender category except one, drivers in theRDPE program had much higher prior accident and citation rates than did drivers in general. This findingsupported the department’s policy of testing drivers referred for medical and other reasons. The prioraccident rates for drivers who passed the RDPE tests were not significantly different from those for driverswho failed the tests. Hence, the validity of using RDPE test results as indicators of accident risk was notconclusively supported by the data. Contrary to expectation, drivers who passed the RDPE tests also hadaccident rates similar to those for drivers who passed the SDT, which indicated that the RDPE tests wereno better than the SDT at distinguishing between higher- and lower-risk drivers. However, because theRDPE tests fail a much higher percentage of referral drivers than does the SDT, the tests do result inaccident savings.


Evaluation of the Delegated Drive Test Pilot Program: Technical Appendix

By: Scott V. Masten

This study evaluated the safety impact of allowing driving schools to administer the Driving PerformanceEvaluation (DPE) to provisional license applicants. The results of the driver record comparisons betweenprovisional applicants tested by the driving schools and those tested by DMV did not indicate a statisticallysignificant difference in the 6-month post-licensure accident or citation rates for the groups. Unfortunately,inadequate sample sizes and the potential biases present in the study preclude drawing any firm conclusionsregarding the comparative safety impact of private versus DMV testing. However, the results of the scoringconsistency and reliability analyses are more interpretable and less subject to these problems. The comparisons ofscoring consistency between driving school and DMV examiners indicates that the driving school examinersfollowed the DPE scoring criteria less stringently than did the DMV examiners, and were far more lenient, havingpassed many applicants who subsequently failed the drive test at DMV. Although these findings also requirequalification, it is very unlikely that differences of the magnitude observed can be attributed to bias alone. The lowvolume of subjects, which was a major reason for the low statistical poser of the analyses, may indicate that themarket for delegated testing is small, both within the general public and the driver training industry itself