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

Note 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
93.1 1985/ 03

An Abstract of License Extensions for Clean-Record Drivers: A Four-Year Follow-Up

By: Shara Lynn Kelsey, Mary K. Janke, Raymond C. Peck & Michael Ratz

To evaluate the traffic safety effect of extending driver licenses by mail for drivers with clean prior four-year records.

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93 1985/ 03

License Extensions for Clean-Record Drivers: A Four-Year Follow-Up

By: Shara Lynn Kelsey, Mary K. Janke, Raymond C. Peck & Michael Ratz

To evaluate the traffic safety effect of extending driver licenses by mail for drivers with clean prior four-year records.

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99 1985/ 10

Development of a Comprehensive Evaluation Design and Data Collection System for Assessment of Provisional Licensing

By: Catherine M. Liddicoat & William C. Marsh

To develop a valid and comprehensive evaluation design and data collection method for assessment of provisional licensing in California.

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NRN006 1976/ 06

Oral Testing of Driver’s License Applicants

By: Margaret Hubbard Jones, Traffic Safety Center, Institute of Safety and Systems Management, University of Southern California

To gather information about several potential test modes which could be used with illiterate applicants and which would serve an instructional purpose without putting a premium on verbal ability.

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NRN009 1985/ 06

The Role of Youth in Traffic Accidents: A Review of Past and Current California Data

By: Raymond C. Peck

To clarify the role of youth in traffic accident causation.

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NRN014 1991/ 07

Evaluation of the Commercial Driver License Knowledge Tests

By: Patricia A. Romanowicz

To provide Program and Policy Administration (PP A) with item and test statistics useful for developing and improving the commercial driver license (CDL) knowledge tests.

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255 2018/ 06

An Evaluation of The Effect of Gaps In Licensure On Traffic Safety Outcomes Subsequent to Renewal

By: Kevin Limrick

Absent a progressive physical or mental condition, motorists in California are permitted to renew their driver license without submitting to a skills test. This policy applies regardless of how long a customer’s license has been expired. Given a lack of published research on the retention of motor skills required of driving, the current study was designed to evaluate the effect of a “gap” in licensure on one’s ability to safely operate a motor vehicle. More specifically, it sought to determine whether a gap in a customer’s licensing history was associated with crashes and / or convictions subsequent to renewal. To that end, the Department’s Driver License Master File was used to identify motorists in California who had a clearly defined gap at some point during their licensing history. These customers were then placed into one of three study groups based upon the length of time it took for them to relicense: 1 to 30 days (n = 6,135), 31 to 365 days (n = 4,688), or greater than 365 days (n = 1,973). A fourth group of drivers, all of whom had not experienced a gap in their licensing history (i.e., those who renewed early), was also identified to serve as a type of quasi-experimental control group. These analyses found that drivers who had a gap of at least 1 year had the same odds of incurring at least one post-renewal conviction as did drivers who renewed early. Logistic regression and Cox proportional hazards models also indicated that gap duration was not a significant predictor of post-renewal crash involvement; drivers in this study were equally likely to experience a post-renewal crash, regardless of how long they were unlicensed. Based on the findings of this report, recommendations are made to maintain current DMV policy and not integrate skills testing as part of the renewal process, absent additional information indicating potential issues of concern (e.g., a progressive vision disorder).

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101 1985/ 11

The Effect of Renewal by Mail for Drivers with Less than Four-Year-Clean Records (Interim Report)

By: Mary K. Janke

To evaluate the traffic safety impact of allowing drivers with a two-year-clean record, but less than a four-year-clean record, to renew their licenses by mail.

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108 1986/ 07

An Evaluation of the Traffic Safety Impact of Provisional Licensing; Interim Report to the Legislature of the State of California – In Accord with Senate Bill 48

By: Robert A. Hagge & William C. Marsh

To evaluate the traffic safety impact of California's Provisional Driver License Program. The primary goal of the program is to reduce the rate of traffic accidents and traffic violations involving 15- through 17-year-olds in California.

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150 1994/ 06

THE CALIFORNIA DRIVER PERFORMANCE EVALUATION PROJECT: AN EVALUATION OF A NEW DRIVER LICENSING ROAD TEST

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.

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