What is the likelihood that underage youth can obtain marijuana from licensed recreational marijuana outlets in California, a state where recreational marijuana is legal?

Objective: Since 2012, 19 states and the District of Columbia have legalized the recreational use of marijuana for adults ages 21 and older. Marijuana use at any level can impair driving performance. Prior research on enforcement of the minimum legal marijuana use age of 21 (MLMU-21) laws is limited.

Measuring Drug Use Among Drivers: How Accurate Is Self-Reported Use?

Objective: There has been considerable work validating self-reported drug use with bioassays, but these studies have not been conducted with respondents on the roadway. The objective of this study was to assess the validity of drivers' self-reported drug use.

Method: This study analyzed 2007 and 2013-2014 data from nationally representative roadside surveys of U.

Marijuana use and driving in Washington State: Risk perceptions and behaviors before and after implementation of retail sales.

Objective: Washington is among the first states to legalize recreational use of marijuana. This study examined marijuana use and risk perceptions before and after retail sales of recreational marijuana began in July 2014, the relationship between risk perceptions and marijuana use, and the relationship between self-reported marijuana use and drug test results.

Methods: Roadside surveys were conducted in 3 waves: June 2014, the month before retail sales of marijuana began; 5-6 months later (November-December 2014); and 1 year later (June 2015).

Fatally injured pedestrians and bicyclists in the United States with high blood alcohol concentrations.

Introduction: Little research has focused on the problem of alcohol impairment among pedestrians and bicyclists in the United States. The aim of the current study was to investigate the prevalence, trends, and characteristics of alcohol-impaired fatally injured pedestrians and bicyclists.

Method: Data from the Fatality Analysis Reporting System (FARS) were analyzed for fatally injured passenger vehicle drivers, pedestrians, and bicyclists 16 and older during 1982-2014.

Impaired driving enforcement practices among state and local law enforcement agencies in the United States.

Introduction: Alcohol-impaired driving (DUI) persists as a substantial problem, yet detailed data on DUI enforcement practices are rarely collected. The present study surveyed state and local law enforcement agencies about their DUI enforcement activities.

Method: Telephone interviews were conducted with law enforcement liaisons in state highway safety offices.

Toyota drivers' experiences with Dynamic Radar Cruise Control, Pre-Collision System, and Lane-Keeping Assist.

Introduction: Advanced crash avoidance and driver assistance technologies potentially can prevent or mitigate many crashes. Previous surveys with drivers have found favorable opinions for many advanced technologies; however, these surveys are not necessarily representative of all drivers or all systems. As the technologies spread throughout the vehicle fleet, it is important to continue studying driver acceptance and use of them.

Vehicle choices for teenage drivers: A national survey of U.S. parents.

Introduction: Previous research has shown that many newly licensed teenagers in the United States are driving vehicles with inferior crash protection. The objective of this study was to update and extend previous research on U.S.

Buick Lucerne drivers' experiences with rear parking sensors.

Objective: Rear parking sensors may have the potential to reduce property damage caused by some low-speed backing crashes, but their effectiveness depends on drivers' acceptance and proper use. This study examined owners' experiences with Buick Lucerne models with a rear parking sensor system.

Methods: Mail surveys were conducted in May 2013 with 426 owners of model year 2010-11 Buick Lucerne sedans equipped with the optional Ultrasonic Rear Parking Assist feature.

The effects of primary enforcement laws and fine levels on seat belt usage in the United States.

Background: Seat belt use in the United States increased from 11 percent in 1979 to 86 percent in 2012. Most of this increase has been attributed to seat belt laws, primary law upgrades, and highly visible enforcement. There has been less research on the effect of fines on seat belt usage.

Use of top tethers with forward-facing child restraints: observations and driver interviews.

Objective: Despite the safety benefits, many parents do not use top tethers with forward-facing child restraints. Detailed information was collected about why parents are not using tethers.

Methods: The sample included 479 drivers who had forward-facing child restraints installed in passenger vehicles equipped with tether anchors.

Volvo drivers' experiences with advanced crash avoidance and related technologies.

Objective: Crash avoidance technologies can potentially prevent or mitigate many crashes, but their success depends in part on driver acceptance. Owners of 2010-2012 model Volvo vehicles with several technologies were interviewed about their experiences.

Methods: Interviews were conducted in summer 2012 with 155 owners of vehicles with City Safety as a standard feature; 145 owners with an optional technology package that included adaptive cruise control, distance alert, collision warning with full auto brake (and pedestrian detection on certain models), driver alert control, and lane departure warning; and 172 owners with both City Safety and the technology package.

Washington State's alcohol ignition interlock law: effects on recidivism among first-time DUI offenders.

Objective: To examine the effects of changes to Washington State's ignition interlock laws: moving issuance of interlock orders from courts to the driver licensing department in July 2003 and extending the interlock order requirement to first-time offenders with blood alcohol concentrations (BACs) below 0.15 percent ("first simple driving under the influence [DUI]") in June 2004.

Method: Trends in conviction types, interlock installation rates, and 2-year cumulative recidivism rates were examined for first-time convictions (simple, high-BAC, test refusal DUI; deferred prosecution; alcohol-related negligent driving) stemming from DUI arrests between January 1999 and June 2006.

Effects of booster seat laws on injury risk among children in crashes.

Objective: Belt-positioning booster seats have been shown to reduce injury risk among child passengers aged 4 to 8 in motor vehicle crashes. To encourage the use of booster seats, many states have enacted laws that require the use of either a child restraint with internal harness or a belt-positioning booster seat, but the specific age range covered by the laws varies by state. Previous studies have found evidence that booster seat laws are effective in reducing injury risk among children, but these studies primarily have included states with younger age requirements (e.

Attitudes toward red light camera enforcement in cities with camera programs.

Objective: To obtain information on attitudes and experiences related to red light camera enforcement in cities with camera programs and in Houston, Texas, where cameras were removed after voters rejected the program in November 2010.

Methods: Telephone surveys were conducted with 3111 drivers in 14 large cities (population greater than 200,000) with long-standing red light camera programs and 300 drivers in Houston, using random samples of landline and cell phone numbers in each city. For analyses combining responses from the 14 cities, cases were weighted to reflect each city's share of the total population for the 14 cities.