Risk of motor vehicle collision associated with cannabis and alcohol use among patients presenting for emergency care.

BACKGROUND: The objective of this study was to examine the relationship between cannabis and alcohol use and occurrence of motor vehicle collision (MVC) among patients in the emergency department (ED). METHODS: This was a cross-sectional study of visits to EDs in Denver, CO, Portland, OR, and Sacramento, CA by drivers who were involved in MVCs and presented with injuries (cases) and non-injured drivers (controls) who presented for medical care. We obtained blood samples and measured delta-9-THC and its metabolites. Alcohol levels were determined by breathalyzer or samples taken in the course of clinical care. Participants completed a research-assistant-administered interview consisting of questions about drug and alcohol use prior to their visit, context of use, and past-year drug and alcohol use. Multiple logistic regression was used to estimate the association between MVC and cannabis/alcohol use, adjusted for demographic characteristics. We then stratified participants based on levels of cannabis use and calculated the odds of MVC across these levels, first using self-report and then using blood levels for delta-9-THC in separate models. We conducted a case-crossover analysis, using 7-day look-back data to allow each participant to serve as their own control. Sensitivity analyses examined the influence of usual use patterns and driving in a closed (car, truck, van) versus open (motorcycle, motorbike, all-terrain vehicle) vehicle. RESULTS: Cannabis alone was not associated with higher odds of MVC, while acute alcohol use alone, and combined use of alcohol and cannabis were both independently associated with higher odds of MVC. Stratifying by level of self-reported or measured cannabis use, higher levels were not associated with higher odds for MVC, with or without co-use of alcohol; in fact, high self-reported acute cannabis use was associated with lower odds of MVC (odds ratio [OR] 0.18, 95% confidence interval [CI] 0.05-0.65). In the case-crossover analysis, alcohol use alone or in combination with cannabis was associated with higher odds of MVC, while cannabis use alone was again associated with decreased odds of MVC. CONCLUSIONS: Alcohol use alone or in conjunction with cannabis was consistently associated with higer odds for MVC. However, the relationship between measured levels of cannabis and MVC was not as clear. Emphasis on actual driving behaviors and clinical signs of intoxication to determine driving under the influence has the strongest rationale.

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. The objective of the current study was to assess the ease of access to marijuana by underage patrons at recreational marijuana outlets in California, where recreational marijuana was legalized in 2016. METHOD: Pseudo-underage patrons were sent to 50 randomly selected licensed recreational marijuana outlets in the state to see if they could enter the outlet without showing a valid identification of their age. RESULTS: Pseudo-underage patrons were required to show age identification to enter in 100% of the licensed recreational marijuana outlets visited. CONCLUSIONS: It appears that licensed California recreational marijuana outlets avoid selling marijuana to underage customers. One reason could be a strong incentive for recreational marijuana outlet owners and managers to avoid being shut down for an illegal activity. PRACTICAL APPLICATION: Underage youth are not obtaining marijuana at licensed recreational outlets. Future studies and cannabis enforcement agencies should investigate whether underage patrons attempt to use fake IDs at licensed marijuana outlets and whether youth are obtaining marijuana from illicit dispensaries or from social sources.

Cannabis presentations to the emergency department after MVC in the era of legalization for recreational use.

INTRODUCTION: The objectives of this study were to examine cannabis and alcohol use among injured patients presenting to emergency departments (ED) in cannabis-legal states to capture an expanded profile of cannabis use and evaluate differences in motor-vehicle collision (MVC) characteristics among those using cannabis alone and in combination with alcohol. METHODS: This was a cross-sectional study of ED visits by drivers in MVC who presented to one of three study sites. Event-related and usual drug and alcohol use information were obtained using a detailed interviewer-administered computerized questionnaire. We also obtained data from blood and breathalyzer tests and the electronic medical record. We examined frequency and types of acute and past-year cannabis and alcohol use and crash mechanisms and characteristics. Our primary method of determining substance use was self-report; we used biosamples secondarily. RESULTS: Eight percent of drivers reported cannabis use in the 8 h prior to MVC, alone or in combination with alcohol; however, a higher proportion (18%) were positive by biosample. High-risk crash features were common in MVCs associated with cannabis, as they were for alcohol use and co-use of cannabis and alcohol; however, patients injured seriously enough to require admission were less likely to report cannabis use (7% vs. 9%) and more likely to report alcohol use (16% vs. 10%). CONCLUSIONS: Cannabis use was common among patients presenting after MVC in this sample of cannabis-legal states. Practical Applications: Differences between self-report and biosample data for cannabis and alcohol use were significant and supports the need to use both means of assessing acute use.

Increased identification of cannabis use among drivers involved in motor vehicle collisions using an expanded cannabis inventory.

OBJECTIVES: The objectives of this study were to implement and examine the potential capture rate of a novel instrument, the Expanded Cannabis Inventory, in a population of emergency department (ED) patients presenting after motor vehicle collisions (MVC). METHODS: Study participants who presented to the ED after MVC were recruited from three hospitals in cannabis-legal states (Denver, CO; Portland, OR; and Sacramento, CA). Research assistants (RAs) administered the Expanded Cannabis Inventory, which includes a wide variety of products that have become readily available in states where cannabis is legal, in addition to assessments related to patient demographic characteristics, general health, cannabis attitudes, and dependency measures. RAs also obtained blood samples for delta-9-THC and metabolites. RESULTS: Among 692 participants who provided responses to questions about cannabis use, 292 (42%) reported past-year use. Seventy-eight (27%) of those identified as using cannabis were only captured due to items in the expanded instrument. These patients were more likely to be White and were more likely to perceive daily use to be of high risk. Fewer had Cannabis Use Disorder Inventory Test (CUDIT) scores consistent with hazardous cannabis use. However, more of the patients only captured by the expanded instrument had high measured blood levels of delta-9-THC on samples obtained in the ED. CONCLUSIONS: Changing cannabis use patterns must be reflected in our measurements for clinical practice, research, and surveillance. Instruments that are the current standard in clinical practice capture limited data and may no longer perform well enough to identify a complete cohort or to provide insight into the health behaviors of patients.

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.S. drivers. Using phi coefficients, the study examined the association between self-reported, past-24-hour drug use and bioassays (based on oral fluid and/or blood) for cannabis, opioids, cocaine, antidepressants, and benzodiazepines. Logistic regression models examined the association of various factors with the odds of reporting specific drug types. RESULTS: Overall phi coefficients by drug type ranged from .17 to .34 in 2007 and .30 to .54 in 2013-2014. The odds of reporting cannabis, cocaine, and benzodiazepine use were significantly higher among drivers who used these substances in 2013-2014 (odds ratio [OR] = 1.92, 2.97, and 3.25, respectively), compared with 2007. Opioid and antidepressant reporting did not differ significantly among users of these substances across survey years (OR = 1.01 and OR = 1.44, respectively). CONCLUSIONS: Roadside surveys of drivers are an important method for gathering the types of data needed to monitor trends in drug use. The findings reinforce the importance of gathering multiple types of data to understand drug use among drivers. The many factors that influence self-reporting, as well as the limitations of biological measures, both pose challenges to accurately measuring drug use. Future studies should investigate ways to improve measurement of drug use in this population.

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). A total of 2,355 drivers completed a marijuana questionnaire about their past and current marijuana use and perceived risks associated with driving after using marijuana. Data collection also included biological specimens (oral fluid and/or blood for marijuana testing and breath for alcohol testing). Drivers who tested positive for delta-9-tetrahydrocannabinol or 11-hydroxy-delta-9-tetrahydrocannabinol in oral fluid or blood were defined as THC-positive. RESULTS: The proportion of drivers who reported recent marijuana use was similar across the 3 surveys. However, the proportion of THC-positive daytime drivers increased from 8% before retail sales to 23% 6 months after retail sales; this proportion did not change among nighttime drivers (19 and 20%). Drivers' perceived risk of impairment by marijuana and perceived risk of being arrested for marijuana-impaired driving were similar before and after retail sales. The odds of being THC-positive were 40% lower among drivers who perceived that marijuana was very likely to impair driving, compared to other drivers. Drivers' perceived risk of being arrested for marijuana-impaired driving was not predictive of THC-positive driving. CONCLUSIONS: The prevalence of daytime THC-positive drivers increased substantially a few months after retail sales of marijuana were legal. Daytime and nighttime prevalence of THC-positive drivers was similar after retail sales. This pattern differs from that typically found for alcohol use, which is consistently higher among drivers at nighttime, compared to daytime. Reports of marijuana use were not always consistent with drug test results, which suggests that comparisons of self-reported marijuana use before and after legalization could be biased. This study examined marijuana use and risk perceptions over the course of 1 year. However, law changes may influence cultural norms gradually over a longer period of time. Future studies should continue to monitor marijuana use over time, as well as identify ways to determine whether drivers are impaired by marijuana.

Use of Alcohol and Cannabis Among Adults Driving Children in Washington State.

OBJECTIVE: It is unknown how many drivers are impaired by alcohol or cannabis with children as passengers (a situation known as driving under the influence child endangerment [DUI-CE]). This study examines the prevalence and patterns of alcohol and cannabis use among drivers with children on weekend nights and risk perceptions among these drivers. METHOD: Data came from 2,056 drivers (1,238 male) who participated in the Washington State Roadside Survey between June 2014 and June 2015. Oral fluid, blood, and breath samples were used to measure cannabis and alcohol use. Self-reported data were used to assess risk perceptions. Descriptive tabulations, weighted prevalence estimates, and chi-square tests were conducted. RESULTS: Compared with other drivers, those who drove with a child were more likely to be driving during the daytime (46.6% vs. 36.3%, p = .03), less likely to be alcohol positive (0.2% vs. 4.5%, p < .0001), but as likely to be positive for Δ-9-tetrahydrocannabinol (THC) (14.1% vs. 17.7%, p = .29). Drivers with a child were less likely to report moderate to severe marijuana problems (3.3%) than those without a child (8.4%) (p < .02). Most drivers reported that cannabis use was very likely to impair driving. Among those who did not perceive any risk, 40.6% of drivers with a child and 28.9% of drivers without a child tested positive for THC. CONCLUSIONS: Although most drivers with children did not drink and drive, many tested positive for cannabis, although it is unclear how many drivers may have been impaired. There is a need to examine driving situations that may put children at risks beyond those related to alcohol.

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. Logistic regression models examined whether personal, roadway, and crash characteristics were associated with high blood alcohol concentrations (BACs) among fatally injured pedestrians and bicyclists. RESULTS: From 1982 to 2014, the percentage of fatally injured pedestrians with high BACs (≥0.08g/dL) declined from 45% to 35%, and the percentage of fatally injured bicyclists with high BACs declined from 28% to 21%. By comparison, the percentage of fatally injured passenger vehicle drivers with high BACs declined from 51% in 1982 to 32% in 2014. The largest reductions in alcohol impairment among fatally injured pedestrians and bicyclists were found among ages 16-20. During 2010-2014, fatally injured pedestrians and bicyclists ages 40-49 had the highest odds of having a high BAC, compared with other age groups. CONCLUSIONS: A substantial proportion of fatally injured pedestrians and bicyclists have high BACs, and this proportion has declined less dramatically than for fatally injured passenger vehicle drivers during the past three decades. Most countermeasures used to address alcohol-impaired driving may have only limited effectiveness in reducing fatalities among alcohol-impaired pedestrians and bicyclists. PRACTICAL APPLICATIONS: Efforts should increase public awareness of the risk of walking or bicycling when impaired. Results suggest the primary target audience for educational campaigns directed at pedestrians and bicyclists is middle-age males. Further research should evaluate the effectiveness of potential countermeasures, such as lowering speeds or improving lighting in urban areas.

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. Officers from a nationally representative sample of municipal, county, and state law enforcement agencies were also interviewed about their agency's DUI enforcement activities, including the types of enforcement, frequency of use, and whether activities were publicized. Response rates were 100% among law enforcement liaisons, 86% among county agencies, 93% among municipal agencies, and 98% among state agencies. RESULTS: Based on the highway safety office survey, 38 states conducted sobriety checkpoints in 2011. Nationally, 58% of law enforcement agencies reported that they conducted or helped conduct sobriety checkpoints during 2011-12, with 14% of all agencies conducting them monthly or more frequently. The vast majority (87%) of agencies reported conducting dedicated DUI patrols. However, dedicated DUI patrols were less likely to be publicized than checkpoints. Less than a quarter of agencies reported using passive alcohol sensors to improve detection of alcohol-impaired drivers. CONCLUSIONS: Results show that 38 states conducted sobriety checkpoints in 2011, little changed from a previous survey in 2000. Despite evidence of effectiveness, many agencies do not conduct frequent, publicized DUI enforcement or use passive alcohol sensors. PRACTICAL APPLICATIONS: The survey suggests that there are several areas in which impaired driving enforcement could be improved: increasing the frequency of special enforcement, such as sobriety checkpoints and/or dedicated patrols; publicizing these efforts to maximize deterrent effects; and using passive alcohol sensors to improve detection of alcohol-impaired drivers.

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. METHOD: This study focused on 2010-2013 Toyota Sienna and Prius models that were equipped with adaptive cruise control, forward collision avoidance, and lane departure warning and prevention (Prius models only). Telephone interviews were conducted in summer 2013 with 183 owners of vehicles with these technologies. RESULTS: About 9 in 10 respondents wanted adaptive cruise control and forward collision avoidance on their next vehicle, and 71% wanted lane departure warning/prevention again. Males and females reported some differences in their experiences with the systems; for example, males were more likely to have turned on lane departure warning/prevention than females, and when using this system, males reported more frequent warnings than did females. Relative to older drivers, drivers age 40 and younger were more likely to have seen or heard a forward collision warning. CONCLUSIONS: Consistent with the results in previous surveys of owners of luxury vehicles, the present survey found that driver acceptance of the technologies was high, although less so for lane departure warning/prevention. Experiences with the Toyota systems differed by driver age and gender to a greater degree than in previous surveys, suggesting that the responses of drivers may begin to differ as crash avoidance technology becomes available on a wider variety of vehicles. PRACTICAL APPLICATION: Crash avoidance technologies potentially can prevent or mitigate many crashes, but their success depends in part on driver acceptance. These systems will be effective only to the extent that drivers use 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. parents' choices of vehicles for their teenagers. METHOD: Telephone surveys were conducted with parents in May 2014 using a random sample of U.S. households likely to include teenagers. Participation was restricted to parents or guardians of teenagers who lived in the household and held either an intermediate or full driver's license. Parents were interviewed about the vehicle their teenager drives, the reason they chose the vehicle for their teenager, and the cost of purchased vehicles. RESULTS: Teenagers most often were driving 2000-06 model year vehicles (41%), with 30% driving a more recent model year and 19% driving an older model year. Teenagers most often were driving midsize or large cars (27%), followed by SUVs (22%), mini or small cars (20%), and pickups (14%). Far fewer were driving minivans (6%) or sports cars (1%). Forty-three percent of the vehicles driven by teenagers were purchased when the teenager started driving or later. A large majority (83%) were used vehicles. The median cost of the vehicles purchased was $5300, and the mean purchase price was $9751. CONCLUSIONS: Although parents report that the majority of teenagers are driving midsize or larger vehicles, many of these vehicles likely do not have key safety features, such as electronic stability control, which would be especially beneficial for teenage drivers. Many teenagers were driving older model year vehicles or vehicle types or sizes that are not ideal for novice drivers. PRACTICAL APPLICATIONS: Parents, and their teenage drivers, may benefit from consumer information about optimal vehicle choices for teenagers.

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. RESULTS: Respondents were primarily older drivers, with 95% older than 60 and 70% older than 70. Nearly all owners reported that they always leave the system on, do not find it distracting, and would want it on their next vehicle. Slightly more than half (56%) said they had heard an alert and noticed something behind their vehicle they did not expect, which most commonly was a person or animal. Owners who said their behavior had changed while using the system mostly reported positive changes (e.g., increased alertness or confidence). In addition to an audible alert, systems on 2010 models provide information on the distance to rear objects via lights located near the rear windshield; 26% of owners with these systems reported never seeing the lights illuminate while backing up, and the percentage increased with age. CONCLUSIONS: Acceptance of the system was high, which is consistent with prior research on early adopters of rear parking sensors. Few owners reported problems using the system, and most problems were likely not attributed to age-related impairments, with the exception of those who did not see the 2010 model's warning lights. Use and acceptance of collision avoidance technologies should continue to be assessed among drivers of all ages as the systems become more widely available.

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. The survey response rates were 21 percent for owners with City Safety, 30 percent for owners with the technology package, and 27 percent for owners with both. Ten percent of owners opted out before the telephone survey began, and 18 percent declined to participate when called. RESULTS: Despite some annoyance, most respondents always leave the systems on, although fewer do so for lane departure warning (59%). For each of the systems, at least 80 percent of respondents with the system would want it on their next vehicle. Many respondents reported safer driving habits with the systems (e.g., following less closely with adaptive cruise control, using turn signals more often with lane departure warning). Fewer respondents reported potentially unsafe behavior, such as allowing the vehicle to brake for them at least some of the time. About one third of respondents experienced autonomous braking when they believed they were at risk of crashing, and about one fifth of respondents thought it had prevented a crash. About one fifth of respondents with the technology package reported that they were confused or misunderstood which safety system had activated in their vehicle. CONCLUSIONS: Consistent with the results for early adopters in the previous survey of Volvo and Infiniti owners, the present survey found that driver acceptance of the technologies remains high, although less so for lane departure warning. This study is the first to report drivers' experiences with City Safety, a collision avoidance system provided as standard equipment on certain Volvo 2010-2012 models, and driver acceptance of this system was high, although not to the same extent as the optional forward collision avoidance system. Future research should continue to monitor drivers' experiences with these technologies as they become available in more vehicles.

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. The survey was conducted primarily at shopping centers, recreation facilities, child care facilities, car seat check events, and health care facilities in mostly suburban areas surrounding Philadelphia, Washington, DC, Fredericksburg (VA), and Seattle. Drivers were surveyed about their knowledge and use of tethers and experience with child restraints. Tether use was observed to verify whether tethers were being used correctly. RESULTS: Fifty-six percent of forward-facing child restraints were installed with the tether; 39% were installed with the tether used correctly. The tether was used with 71% of LATCH lower anchor installations and 33% of seat belt installations. Drivers who installed child restraints without tethers most often said they did not know about the tether or how to use it. CONCLUSIONS: Although the tether use rate was slightly higher in the current research than in previous studies, many parents and caregivers still use forward-facing child restraints without attaching the tether. Because the main problem is lack of awareness of the tether or how to use it, public education should focus specifically on the safety benefits of tethers and how to use them. PRACTICAL APPLICATIONS: Information about why caregivers fail to use top tethers is potentially useful to child restraint manufacturers, child passenger safety technicians, and others who work with parents to improve motor vehicle safety.

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. METHODS: We examined law type and fine levels as predictors of seat belt use among fatally injured occupants of passenger vehicles from 1997 through 2008 using data from the Fatality Analysis Reporting System (FARS). Fine levels used were the statutory maximum base fines for a first offense. RESULTS: Having a primary enforcement law was associated with a 9 to 10 percentage point increase in seat belt use. An increase in the fine amount, from the current median level of $25 to a level of $60, was associated with a 3 percentage point increase in usage. An increase in fine from $25 to $100 was associated with a 6- to 7-point increase. Such increases were in addition to the effects of a shift from secondary to primary enforcement. DISCUSSION: The results of this study suggest that, in addition to current emphases on primary law upgrades and high-visibility enforcement of seat belt usage, increasing fine levels provides another viable strategy for increasing seat belt use. In addition, based on these results, states should consider publicizing such increases just as they publicize enforcement efforts.

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. Regression analyses examined recidivism effects of the law changes and interlock installation rates. To examine general deterrent effects, trends in single-vehicle late-night crashes in Washington were compared with trends in California and Oregon. RESULTS: After the 2004 law change, the proportion of simple DUIs declined somewhat, though the proportion of negligent driving convictions (no interlock order requirement) continued an upward trend. Interlock installation rates for first simple DUIs were 3 to 6 percent in the year before the law change and one third after. Recidivism declined by an estimated 12 percent (e.g., expected 10.6% without law change vs. 9.3% among offenders arrested between April and June 2006, the last study quarter) among first simple DUI offenders and an estimated 11 percent (expected 10.2% vs. 9.1%) among all first-time offenders. There was an estimated 0.06 percentage point decrease in the recidivism rate for each percentage point increase in the proportion of first simple DUI offenders with interlocks. If installation rates had been 100 vs. 34 percent for first simple DUI offenders arrested between April and June 2006, and if the linear relationship between rates of recidivism and installations continued, recidivism could have been reduced from 9.3 to 5.3 percent. With installation rates of 100 vs. 24 percent for all first offenders, their recidivism rate could have fallen from 9.1 to 3.2 percent. Although installation rates increased somewhat after the 2003 law change, recidivism rates were not significantly affected, perhaps due to the short follow-up period before the 2004 law change. The 2004 law change was associated with an 8.3 percent reduction in single-vehicle late-night crash risk. CONCLUSIONS: Mandating interlock orders for all first DUI convictions was associated with reductions in recidivism, even with low interlock use rates, and reductions in crashes. Additional gains are likely achievable with higher rates. Jurisdictions should seek to increase use rates and reconsider permitting reductions in DUI charges to other traffic offenses without interlock order requirements.

Traffic citation rates among drivers of different residency status in the United States.

Racial/ethnic groups in the United States may be overrepresented in motor-vehicle incidents (crashes and violations), particularly among low-acculturated immigrants coming from countries in which traffic laws are not well enforced. Some evidence suggests just the opposite. We collected and analyzed information on the residency status of licensed drivers in Florida and Tennessee to examine the hypothesis that the prevalence of seat-belt nonuse, DWI, speeding, and failures to obey a traffic signal was higher among recent immigrants than among US citizens. We rejected this hypothesis. Both in Florida and Tennessee, US citizens were more likely to be cited for DWI, seat-belt, or speeding violations than the noncitizens. However, immigrants were more often cited for failure-to-obey than US citizens. We concluded that residency status does, appear to play a role in the likelihood of traffic violations, but this role is far from uniform; varying depending upon the type of traffic violation, the racial/ethnic group, and the state in which the violation occurred.

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. RESULTS: Among drivers in the 14 cities with red light camera programs, two thirds favor the use of cameras for red light enforcement and 42 percent strongly favor it. The chief reasons for opposing cameras were the perceptions that cameras make mistakes and that the motivation for installing them is revenue, not safety. Forty-one percent of drivers favor using cameras to enforce right-turn-on-red violations. Nearly 9 in 10 drivers were aware of the camera enforcement programs in their cities, and 59 percent of these drivers believed that the cameras have made intersections safer. Almost half know someone who received a red light camera citation, and 17 percent had received at least one ticket themselves. When compared with drivers in the 14 cities with camera programs, the percentage of drivers in Houston who strongly favored enforcement was about the same (45%), but strong opposition was higher in Houston than in the other cities (28 versus 18%). CONCLUSIONS: Most drivers in cities with long-standing red light camera programs support cameras and believe that the cameras have improved safety, but communities could do a better job of educating the public about the dangers of right-turn-on-red violations and the need for enforcement. Given that camera opponents frequently said cameras make mistakes, it appears that communities also could do a better job of explaining the safeguards that ensure that citations are issued only to drivers who clearly run red lights.

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.g., ages 4-6) for booster seats. The objective of the present study was to examine the effectiveness of booster seat laws in several states that cover children through age 7 or 8. METHODS: Police-reported crash data from 5 states--Missouri, North Carolina, Pennsylvania, Wisconsin, and Wyoming--were used to compare population-based injury rates, restraint use, and seating position among children before and after booster seat laws. The pre-law period was comprised of the 2 calendar years prior to the year of enactment of the booster seat law, and the post-law period was comprised of the 2 calendar years after the year of the effective start of the booster seat law. Effectiveness estimates were adjusted using a comparison group of children aged 9 to 12 in the same states who were not covered by the booster seat laws. RESULTS: Among children in crashes who were affected by law changes in the 5 study states, the per capita rate of children using child safety seats (either a harnessed child restraint or booster seat) increased nearly 3 times, and the per capita rate of children riding in rear seats increased 6 percent after the booster seat laws were implemented. Booster seat laws were associated with a 5 percent reduction in the per capita rate of children who sustained injuries of any severity and a 17 percent reduction in the per capita rate of children who sustained fatal or incapacitating injuries. CONCLUSIONS: Results provide evidence that booster seat laws are effective in increasing the use of child safety seats, increasing the placement of children in rear seats, and reducing injuries, especially severe injuries, among children covered by the laws.