Improving Safety in the Work Zone

by Courtney Murtagh, Intern, and Tracy Zafian, Research Fellow

In 2015, 860 vehicle crashes in roadway work zones were reported in Massachusetts, and over 96,000 crashes in work zones nationwide. Researchers and state officials have been examining the causes, and options for reducing work zone crashes, injuries, and fatalities.

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Work zone area on the MassPike during the removal of toll booths. (Boston Herald, photo credit Angela Rowlings)

With summer in full swing, we find ourselves in the midst of another road infrastructure improvement and repair season. Drivers may have noticed an increase in the number of work zones along state and town highways in Massachusetts. During these warmer months, drivers need to take extra precautions for their safety and the safety of road construction workers.

The Federal Highway Administration (FHWA) recorded a total of 765 work zone traffic fatalities nationwide in 2016, in the Fatality Analysis and Recording System (FARS). This is a 7% increase from 2015.  Many of these fatalities (83%) were of motor vehicle drivers or passengers, the remainder were pedestrians, bicyclists, and other non-motorists. Relatedly, the U.S. Bureau of Labor Statistics found that there were 143 deaths of road workers at construction sites. This count overlaps with the FARS figures. Forty percent of the traffic fatalities in work zones are from rear-end collisions, as vehicles fail to slow down adequately approaching and traveling through the work zones.

According to the FHWA, there were 96,626 crashes in work zones in 2015, a 42% increase since 2013. The same study showed that nationwide there were on average 70 work zone traffic crashes with injury per day that year.

For Massachusetts, the State Police reported 860 work zone crashes for 2015. The data show that work zone crashes occur most often between May and September, during the day, and on a Tuesday, Wednesday or Thursday. Drivers should be especially cautious and attentive when traveling through work zones, as construction workers may be present and as drivers may be asked to stop.

Speed limits in work zones are set according to state law. The law allows for the doubling of speeding fines in work zone areas.

In 2016, MassDOT created a Work Zone Safety Task Force to consider innovative engineering and technology-related solutions for better work zone safety. The Work Zone Task Force implemented some new safety features in work zones in 2017, including portable rumble strips, and flashing blue LED lights in work zones to simulate a police presence and get drivers to reduce their speed. Another type of technology being considered are smart cones, which communicate with construction workers to warn them when potential threats, such as a speeding or erratically driving vehicle, are approaching a work zone. A previous Innovative Outlook article discussed some of the technology options for improved work zone safety in more detail.

Another potential way to reduce work zone crashes is the ‘zipper’ merge. The zipper occurs when two lanes of traffic equally merge into one. Research conducted at UMass Amherst by Dr. Michael Knodler and Civil Engineering graduate students Alyssa Ryan and Francis Tainter has been investigating the potential use of zipper merges to help improve traffic safety. UMass Amherst’s zipper merge research was discussed in the March and April 2018 Innovative Outlook. An FHWA analysis of FARS crash fatality data found improper merging to be the second most dangerous driving maneuver, behind only inattentive driving. The zipper merge is hypothesized to improve both roadway safety and efficiency, including in work zone areas.

Prospects and Challenges for Automated and Autonomous Vehicles

by Tracy Zafian, Research Fellow

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May 2018: A car driven with Tesla’s Autopilot driver assist system crashed into a parked police car. The Autopilot system is designed to be used on limited access highways, not on roadways such as this one. (Source: Uncredited/AP/Rex/Shutterstock)

In March 2018, an Uber Volvo operating in automated driving mode, with a driver at the wheel, hit and killed a pedestrian in Arizona. It was the first autonomous vehicle (AV)-related pedestrian fatality. There have been other crashes involving autonomous test vehicles and additional fatalities involving lower-level automated vehicles since.  Also in March, a driver in California was killed when his Tesla, in autopilot mode, crashed into a concrete highway lane divider and caught fire. Last month, a Tesla, in autopilot mode, crashed into a parked firetruck in Utah and into a parked police car in California.  Injuries were minor in these instances.

All of these crashes have occurred while there has been a driver at the wheel making decisions about when to use and disengage the automated driving assist system. As reported in a USA Today article, following the Utah firetruck crash, Tesla issued a statement saying, “When using Autopilot, drivers are continuously reminded of their responsibility to keep their hands on the wheel and maintain control of the vehicle at all time,” and, “Autopilot is designed for use on highways that have a center divider and clear lane markings.” These conditions are not always met when crashes occur; for example, the driver in the Utah crash admitted to being distracted by their phone before the crash. From the National Transportation Safety Board’s preliminary findings from investigating the Uber pedestrian crash, there was no warning given to the safety driver before the crash. Current AV technologies, such as Tesla’s Autopilot, are referred to by car manufacturers as “driver assistance systems” but it is not clear that all drivers understand their limitations, including the need for drivers to monitor the driving environment and stay involved in the driving process.

The Society of Automotive Engineers has developed a classification system for autonomous vehicles. The classification includes six levels (Level 0-5); with Level 5 being fully autonomous and Level 1, containing some automated features such as adaptive cruise control and parking assist. Most current automated driver assistance systems are Level 1 or 2, meaning that drivers still need to be actively involved.

Driver assistance systems and autonomous vehicles hold great promise for improving safety and mobility, but AV technologies are still relatively new, and numerous challenges remain. A number of universities and researchers in Massachusetts are exploring this topic. In April, a commentary by MIT AgeLab researchers, “People must retain control of autonomous vehicles,” was published in Nature magazine (link is for the article). In their remarks, Dr. Ashley Nune, Dr. Bryan Reimer, and Dr. Joseph Coughlin, Age Lab Director and UMass Transportation Center Research (UMTC) Affiliate, focused on two areas – safety and liability – that need urgent attention as policies and regulations are developed for autonomous and semi-autonomous vehicles. They write that, in their view, “some form of human intervention will always be required. Driverless cars should be treated much like aircraft, in which the involvement of people is required despite such systems being highly automated. Current testing of autonomous vehicles abides by this principle. Safety drivers are present, even though developers and regulators talk of full automation.” The researchers’ piece ends with key points for policymakers preparing AV legislation to consider:

  • Driverless does not, and should not, mean without a human operator
  • More information should be shared with operators/drivers about how well different autonomous and driver assist systems are working, including their reliability and limitations
  • Operators should need to demonstrate that they understand the autonomous and driver assist systems in their vehicles and should be tested on their understanding and competence at periodic intervals
  • Remote monitoring networks should be established and shift time guidelines considered for workers monitoring AVs.

In May, a forum held at Harvard University’s T.H. Chan School of Public Health on “Self-Driving Cars: Pros and Cons for the Public’s Health.” (A recording of this session and a transcript are available at this link.) Dr. Jay Winsten, Associate Dean for Health Communication at Harvard, said there is hope right now around the potential for autonomous and highly automated vehicles to reduce traffic deaths.  He also addressed the hype around this: “I think both the media and some of the manufacturers and developers have been going a little too far in setting public expectations for what to expect, especially in the short-term and in the medium-term.” The panelists discussed that initially most vehicles will be highly automated (SAE Level 2), not autonomous (Level 3-5), and the deployment of the autonomous vehicles is likely to occur first for long-distance, highway-based commercial transport and in urban areas for shuttles and other short-distance trips. There are some challenges including the current reliability and drivers’ understanding of AV technologies, including the need for drivers to stay alert while behind the wheel and the safety of vulnerable road users. There are also concerns regarding regulation. The federal government through the National Highway Safety Administration has developed some guidelines regarding autonomous vehicles and automated driving systems. However, there are currently no federal regulations in place regarding autonomous vehicles. Therefore, currently regulations are primarily set at the state level.

As described in an earlier Innovative Outlook article, Governor Baker and Massachusetts state officials have largely taken the approach that it is better not to regulate AVs through legislation, as the technologies are still evolving and legislation can be difficult to modify once passed. Panelist Deborah Hersman of the National Safety Council, shared those concerns, saying “We’ve got to find out how to do this differently” so that any regulations keep up with changing technology. Herman also urged there be more transparency and data sharing regarding specific AV technologies and how well they perform, saying that NTSB investigations after a crash can be challenged by lack of access to such data.

In June 2018, MassDOT entered into a Memorandum of Understanding with several municipalities to help facilitate and expand autonomous vehicle testing on roadways in Massachusetts. As described in a MassDOT blog article, “Following the signing of this MOU, MassDOT and the participating communities will finalize a universal application for companies to use when seeking to test autonomous vehicles and the participating municipalities will identify locations and roadways suitable for autonomous vehicle testing. ‘This agreement will allow companies to responsibly develop and test autonomous vehicle technology in Massachusetts, while ensuring there are uniform safety guidelines in place,’ said Governor Baker [at the MOU signing] . ‘The MOU builds on the existing autonomous vehicle testing framework while simplifying the process for municipalities to work with innovative companies that are seeking to advance transportation, create jobs in our nation leading innovation economy, and improve our quality of life in the Commonwealth.’  …Said Lieutenant Governor Karyn Polito, ‘By creating a standardized process and working collectively with local officials, we can generate economic growth and support our communities as they play a role in the future of innovation and motor vehicle automation.’ Fourteen communities signed the MOU initially, including Boston, Worcester, Arlington, Boston, Braintree, Brookline, Cambridge, Chelse, Medford, Melrose, Newton, Revere, Somerville, Weymouth, Winthrop, and Worcester.  In addition, the Massachusetts Department of Conservation and Recreation also joined the MOU, allowing Commonwealth-owned parkways to be available for autonomous vehicle testing.

 

 

Safety for Older Drivers

by Tracy Zafian, Research Fellow

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AAA has estimated that by 2030, there will be more than 60 million people in the U.S. age 65 & over licensed to drive. (Photo source: IIHS.org, credit istock.com/KLH49)

Most people outlive their ability to drive by seven to ten years. This important statistic from the American Automobile Association (AAA) was cited by Michele Ellicks of the Massachusetts Registry of Motor Vehicles (RMV) at the April 2018 MassDOT Innovation and Mobility Exchange, at a session on Safe Driving for Seniors and People with Disabilities.

There were more than 40 million drivers age 65 years and older in the U.S. in 2015, according to the Federal Highway Administration (FHWA). This population is expected to increase significantly in coming decades. AAA has estimated that by 2030, there will be more than 70 million people in the U.S. in this age group with approximately 85-90% of them licensed to drive. In 2016, 18% of all traffic-related fatalities in the U.S. involved people age 65 and older. In Massachusetts, 16% (133) of all traffic fatalities in the state involved people age 65 and older. Over half (54%) of those fatalities were for those age 65 to 74; the other 46% were for those age 75 and older.

Nationally, the fatality rates per 100,000 people are higher for males than females and generally higher for people age 80 and over than for those 65-79 (see chart below). The death rates increase with age because older people have more physically frail and are more likely to die from injury, as found in this study from John Hopkins School of Medicine. Older drivers are also more likely to be involved in at-fault crashes as a result of physical or cognitive impairments. The fatality rates for females fall slightly from age 80-84 to age 85 and older because females limit or cease their driving in their upper 80s more often than males.

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Source: Insurance Institute for Highway Safety Analysis of National Highway Transportation Safety Administration (NHTSA) FARS (Fatality Analysis Reporting System) 2016 data, released December 2017. Viewed at http://www.iihs.org/iihs/topics/t/older-drivers/fatalityfacts/older-people.

Intersections can be especially difficult for older drivers to navigate. Extensive research conducted at the University of Massachusetts Amherst on driving simulators and on-road has shown that older drivers do not look as often as other drivers towards their turning direction or other vehicles when turning at T-intersections or four-way intersections. As a result, older drivers may be more likely to be involved in traffic crashes.

UMass Amherst researchers working under the supervision of Dr. Michael Knodler are currently investigating older drivers’ crashes during left-turns at signalized intersections; using data gathered from their vehicles and the drivers themselves as part of the SHRP2 (Strategic Highway Research Program 2) project to collect naturalistic driving data on over 2,300 drivers at six cities around the country. The researchers hope this study will help with understanding why and how left turns across path crashes at intersections are more likely for older drivers.

In previous older driver research conducted at UMass Amherst, Dr. Matthew Romoser conducted one study on drivers age 72 to 87 and a comparison group of drivers age 25 to 55 for his dissertation, and then a follow-up study with the older drivers as a post-doctoral researcher. Romoser’s first study, conducted with his advisor, Dr. Donald Fisher, UMass Transportation Center (UMTC) Research Affiliate and UMass Amherst Human Performance Laboratory (HPL) Director, found that the older drivers took fewer roadway glances towards potential hazards than younger drivers while turning. Romoser also found that providing active training and customized feedback regarding their driving to the older participants led to significant improvements in their glances both in a driving simulator and on-road, towards potential hazards as they approached and went through intersections. Romoser’s follow-up study, conducted two years after the first study with the same older drivers, found that those drivers who received active training in the first study still made 50% more glances towards potential hazards than they did before training two years earlier.

The benefits of training programs to help older drivers stay safe at intersections was further examined in a study by past HPL researchers Dr. Siby Samuel and Dr. Yusuke Yamani, with Dr. Fisher. This research found that training programs, such as Dr. Romoser’s, which help improve older drivers’ glance behaviors at intersections, can be effective even though they don’t address underlying declines in cognitive, visual, and motor functions for these drivers as they age. The researchers found some evidence that these training programs are effective because, through the training, drivers learn to decouple their hand, foot, and head movements at intersections, and that doing so may help reduce the impacts of cognitive, motor, and visual declines on their driving.

This research is promising and suggests that some types of training may help older adults safely continue to drive longer than they would be able to otherwise. In Massachusetts, various measures have been taken to promote older driver safety. Under state law, for drivers age 75 and over driver license renewals must be done in person and they include an eye exam. The RMV holds free workshops around the state on issues facing older drivers, including if and when an older person should give up driving.

For adults who do stop driving for safety reasons, MassMobility is a state initiative to improve the transportation options for adults who don’t have a car. The options include both traditional transportation providers such as buses and paratransit and also newer alternatives such as Uber, Lyft, and other Transportation Network Companies (TNCs). A number of sessions at this year’s Innovative and Mobility Exchange discussed alternatives for meeting transportation needs for this population. Options included using TNCs to provide rides outside of regular bus service hours and TNCs partnering with senior centers and other agencies to offer rides to people who otherwise might not be able to access (because they don’t have a smartphone or credit card) services from companies such as Uber and Lyft.

Dr. Nina Silverstein, UMTC Affiliate and Professor of Gerontology at UMass-Boston, recently co-authored a book, Introduction to Senior Transportation: Enhancing Community Mobility and Transportation Services (2018). The book provides an overview of the mobility needs of older adults and the “transportation methods that do and do not currently meet the needs and wants of senior passengers.”

Drunk Driving…Continues to be a Major Concern

by Tracy Zafian, Research Fellow

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from: White & Associates Law, MN

A bold new report leads with that statement and recommends a multi-faceted, comprehensive approach to eliminating drunk-driving related deaths. The report comes from the Committee on Accelerating Progress to Reduce Alcohol-Impaired Driving Fatalities, a committee convened by the National Academy of Sciences, Engineering, and Medicine to address this topic. The committee supports the concept of Vision Zero, stating in their report that “no alcohol-impaired driving deaths are acceptable, and that every stakeholder has a role in preventing these deaths.”

“Alcohol-impaired driving remains the deadliest and costliest danger on U.S. roads today.  Every day in the U.S., 29 people die in an alcohol-impaired driving crash – one death every 49 minutes – making it a persistent public health and safety problem.”

The report documents how, beginning in the 1980s, steps were taken to reduce drunk driving and to educate the public about its dangers. Such steps included new laws making it illegal to drive with a blood alcohol concentration (BAC) level above a certain level. These approaches lead to a decrease in drunk driving-related fatalities for two decades, but now the decline in these fatalities has plateaued. It is clear that a new approach is needed for progress to continue.

The committee created a conceptual framework to show the sequence of behaviors that can lead to an alcohol-impaired driving fatality, potential interventions for this behavior, and important factors that impact outcomes. The interventions would interact with each other at multiple levels, including “individual, interpersonal, institutional, community, and societal.”

The interventions fall into four primary categories:

  • Interventions to reduce drinking to impairment, such as limiting alcohol availability and marketing, especially for under-age drinkers
  • Interventions to reduce driving while impaired, including: creating viable, affordable, safe transportation alternatives for drinkers who may drive; strongly enforcing drunk driving laws; and promoting the use in-vehicle technologies that can restrict drivers with over a threshold BAC level from being able to start their vehicle.
  • Post-arrest and post-crash interventions, such as health care programs for preventing, evaluating, and treating alcohol dependency; and increased support both for first-time driving under the influence (DUI) offenders as well as habitual offenders to modify these behaviors.
  • Data and surveillance systems, including: expanding and standardizing data collection on alcohol-impaired related crashes, arrests, and convictions, long-term outcomes, and why people drive while impaired; and integrating the collected data sets for research, evaluation, and data-sharing purposes.

 Massachusetts has a history of addressing the issue of alcohol-impaired driving using education and enforcement with the coordination of multiple agencies. Each year for example, the state Executive Office of Public Safety and Security leads the Drive Sober or Get Pulled Over enforcement and education effort over the December-New Year holiday season.  This effort includes high visibility police patrols and impaired driving enforcement at high crash locations across the state. One result of Massachusetts’ efforts is that the rate of alcohol-impaired traffic deaths in Massachusetts is consistently among the lowest in the nation. Moreover, the rate of alcohol-related driving deaths in Massachusetts has fallen approximately 20 percent since 2007. However, as with the national trends, the decrease in these deaths in Massachusetts has slowed in recent years, and between 2015 and 2016, there was actually a small increase from 109 to 119 people killed statewide in alcohol-related crashes.

New Federal Committee on Motorcycle Safety Holds First Meeting

by Tracy Zafian, Research Fellow

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Last month, the Motorcycle Advisory Committee (MAC) held its initial meeting in Arlington, VA. This federal committee was created to advise the Federal Highway Administration (FHWA) on motorcycle safety and to identify engineering-related infrastructure solutions for reducing motorcyclist fatalities.

There were 5,286 roadway fatalities nationally involving motorcycles in 2016, an increase of 5% from the previous year. In Massachusetts, 40 motorcyclist fatalities were reported during the same year.

As described on transportation.gov, “the MAC consists of ten members selected by the U.S. Secretary of Transportation Elaine L. Chao. [The members] come from across the country and are experts in a wide range of motorcycle-infrastructure topics. Each is a motorcyclist and, combined, the MAC members have over two centuries of riding experience.”

At the first MAC meeting, there were substantial discussions on many infrastructure issues, including work zones, roundabouts, roadside hardware, roadway maintenance practices, the potential consequences of automated vehicles and crash testing, among others. At upcoming meetings, the MAC will determine how to advise FHWA on these issues. For its part, FHWA has research underway to identify key infrastructure-based safety issues for motorcyclists. The centerpiece of this work is the FHWA’s Motorcycle Crash Causation Study. According to the study web site, “The Motorcycle Crash Causation Study is the most comprehensive data collection effort to study the causes of U.S. motorcycle crashes in more than 30 years. The dataset includes data from at least 351 crash investigations, and 702 control rider interviews.”

A couple of current safety features on motorcycles to prevent future fatalities include: new breaking lights and the required anti-lock brake feature. The break light feature is the first wearable brake light connected to a smart phone app.  The anti-lock brake feature has been an option on motorcycles for years, but it may soon become a requirement based on the safety advantages.

In addition to technology and infrastructure improvements for motorcycle safety, some changes in how motorcyclists are trained may be warranted as well. Researchers at UMass-Amherst, led by now Ph.D. graduate Jeffrey Muttart, have conducted field studies on motorcyclist eye glance and driving behavior, including studies where participants went through the same on-road course as car drivers and as motorcyclists. Key findings in one study were that motorcyclists were less likely to come to a complete stop at a stop sign than car drivers, and that study participants made later final glances toward the direction of the most threatening traffic before they made a turn when they were driving a car than when they were riding a motorcycle.

New Year, New UMass Human Performance Lab Web Site

By Tracy Zafian, UMTC Research Fellow

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Photo Source: Shannon Roberts, Human Performance Lab, UMass Amherst

The Human Performance Lab (HPL) based at the University of Massachusetts-Amherst has a brand new look! The HPL was originally created by Professor Donald Fisher in the 1990s and is world-renowned for its work on teen driver training. In 2016, the University of Massachusetts Transportation Center (UMTC) Affiliate Researcher Professor Shannon Roberts joined the HPL and now serves as the HPL co-director, overseeing research activities of the lab and day-to-day operations. Professor Roberts’ research is focused on driver feedback, in-vehicle interface design, automated vehicles, and teen/novice drivers. Her research group’s web site has information on her team and other interests.

With Dr. Robert’s arrival, the lab underwent significant changes. Upgrades include a new vehicle (2015 Ford Fusion), five new projectors with an expanded field of view of 330 degrees, new channels for displaying the side and rear-view mirrors and a new in-vehicle display.  The HPL has also obtained other new equipment including Virtual Reality (VR) headsets for delivering training and using with simulations, and a new heart-rate monitor to use with participants in lab studies.  Coming soon will be an instrumented vehicle for use with on-road studies.  The upgraded equipment will significantly expand the lab’s research capabilities.  One recent new area of research for the lab involves autonomous vehicles.  This is the transfer of driving control from driver to vehicle, and drivers’ awareness of their surroundings and ability to respond to potential roadway hazards as they switch from autonomous modes that require more attention and input from the driver, to those that require less attention.

As it has since its beginning, the lab, based in the Department of Mechanical and Industrial Engineering, continues to collaborate with other departments at UMass-Amherst including Civil Engineering, the UMTC, Computer Science, Electric and Computer Engineering, and Psychology.

GHSA Announces New Research Partnership with Transportation Research Board

by:  Matt Mann, Research Program Coordinator

The Governors Highway Safety Association (GHSA) is pleased to announce the launch of a new forum for collaborative research through the Behavioral Traffic Safety Cooperative Research Program (BTSCRP).  Speaking with Kara Macek, GHSA, “this partnership between GHSA and TRB brings a Research Panel together that will provide oversight and ownership, while promoting actionable results on each project.”

Using Advanced Science and Technology to Detect Marijuana Use

by Tracy Zafian, Research Fellow

Massachusetts is one of twenty-nine U.S. states, plus the District of Columbia, that now legally allow marijuana for recreational or broad medical uses or both (full list of these states available here). The Massachusetts Executive Office of Public Safety and Security (EOPSS) recently launched a public safety campaign, Drive Sober or Get Pulled Over, to warn and inform the public about the impairments that marijuana causes in drivers and the increased driving danger when alcohol and marijuana are combined. Marijuana is proven to impact the brain’s ability to function properly. Marijuana’s primary psychoactive ingredient, tetrahydrocannabinol (THC), has been shown to slow reaction times, impair coordination, and decrease decision-making ability.

One challenge for enforcement regarding marijuana use and driving is that impairment from marijuana is more difficult to measure than impairment from alcohol. There is currently no proven equivalent to an alcohol type breathalyzer test that measures blood alcohol concentration (BAC) levels to assess drunk driving. Unlike alcohol that dissolves in water, THC dissolves in fat. As toxicologist Marilyn Huestis discussed in an NPR story, this means that that the length of time that THC lingers in the body varies more than with alcohol, and is influenced by factors such as amount of body fat, type of cannabis product consumed, and frequency of use. It also means that a person’s blood THC levels may not directly correlate to when they are most impaired.  Some states such as Colorado, Washington, Montana and Pennsylvania, define marijuana impairment using blood THC levels to legally define when someone is too impaired to drive. The state regulations in Ohio and Nevada determine impairment by blood tests and urine tests.

The San Diego Police department, and other enforcement agencies in New York, Arizona, and Nevada, have been screening drivers for THC using a mouth-swabbing testing device (the Dräger DrugTest 5000), which can test for the presence of seven drugs, including marijuana. The marijuana test is for delta-9 THC, the active THC compound which creates the high from marijuana. Unlike other components of THC, delta-9 THC typically only stays in a person’s system for a few hours and not days or weeks.  Stanford University researchers have been developing a saliva-based test for THC using magnetic nanotechnology.  Recently, police departments have been pilot testing a handheld breathalyzer for marijuana detection from Hound Labs. The device measures delta-9 THC levels and is able to detect marijuana from either inhaling or edibles. Cannabis Technologies is also developing a marijuana breathalyzer.  These THC detection methods are often used in conjunction with other field sobriety and impairment testing.

In Massachusetts, Drug Recognition Experts (DREs) are specially trained to detect impairment from drug use.  A full DRE exam takes about an hour and includes physiological measures (blood pressure, pulse, eye exams), and performance measures (balance, coordination). As described in a 2016 Boston.com article Massachusetts and other states are now offering a less intensive training, Advanced Roadside Impaired Driving Enforcement (ARIDE), which is still a step above typical field sobriety training.

In a September 2017 Massachusetts Supreme Court decision, the Court found that police cannot use standard field sobriety tests to determine definitively that a driver is too high to drive. The court determined that the standard sobriety tests were developed to evaluate alcohol intoxication and there is not yet sufficient evidence that they are indicative of marijuana intoxication.  Under the ruling, police officers can still conduct field sobriety tests and testify about their observations regarding a driver’s demeanor and ability to perform physical coordination and mental tasks.

Dr. Michael Millburn, a Psychology professor at UMass Boston, has been developing a smart device app to assess driver impairment called DRUID.  This app has been designed to measure cognitive and behavior impairment from marijuana, alcohol, prescription drugs and other brain-based contributors to impairment, such as fatigue. It contains a series of four different tests for reaction time, errors in decision making, motor tracking, and time estimation and balance. The app then integrates the results of each of the individual tests into an overall impairment score. The tests are completed in 5 minutes total.  The app was developed to help people assess their own impairment, but could also be adapted for police use.  The app is currently being tested at Brown Medical School.  Research shows that some types of marijuana have non-linear patterns of impairment following consumption. Apps such as this could be useful for supporting driver safety and important complements to other tools and tests for measuring THC, alcohol, and other substances that can impair driver performance.

Cambridge police officer Jason Callinan, a drug recognition expert, or DRE, performs the Horizontal Gaze Nystagmus (HGN) on Jeremy Warnick, the department's spokesman, as part of a demonstration. (Jesse Costa/WBUR)
Cambridge police officer, Jason Callinan, a drug recognition expert, or DRE, performs a demo of a field sobriety test.   (Source: Jesse Costa, WBUR)

Written by Tracy Zafian, UMTC Research Fellow