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November 2, 2021Episode 20. From BAC to THC: How the impaired driving danger is evolving.
FEATURING: Troy Walden
The latest statistics tell us that while driving drunk has become a bit less common, driving high is more prevalent than ever. As Senior Research Scientist Troy Walden explains, what exactly constitutes driving under the influence is not as simple as it once was, especially given the constantly changing landscape of state laws.
About Our Guest
Senior Research Scientist
Troy Walden is director of TTI's Center for Alcohol and Drug Education Studies. Dr. Walden has over 30 years of experience in highway safety as a law enforcement officer, crash re-constructionist, traffic safety advocate and impaired driving researcher. He has written and presented his research findings at state, national and international conferences and served as a member of several statewide impaired driving advisory committees.
Bernie Fette (host) (00:00):
Welcome. This is Thinking Transportation — stories about how we get ourselves and the things we need from point A to point B, and all that can happen in between. I’m Bernie Fette with the Texas A&M Transportation Institute.
Bernie Fette (00:32):
Impaired driving has been a problem for as long as we’ve had automobiles. The first laws against it were passed more than a century ago, but it wasn’t until around 1980 that the laws started to become tougher and public awareness of the problem became more widespread. While alcohol-impaired driving remains a persistent threat to roadway safety, some measures of the problem have actually been improving. At the same time, drug-impaired driving has become more prevalent, as more states have legalized the recreational use of marijuana. Studying those trends helps to keep Troy Walden busy. He’s a senior research scientist at TTI, and he’s a former police officer. Glad you could make time to join us, Troy.
Troy Walden (guest) (01:22):
Well, I’m glad to be here. Thanks for the invitation.
Bernie Fette (01:25):
According to the National Highway Traffic Safety Administration, fewer people are driving drunk, but more people are driving high, specifically impaired by THC. And I’m going to go ahead and invite you to spell that out for us.
Troy Walden (01:39):
Sure. THC is the acronym for tetrahydrocannabinol.
Bernie Fette (01:43):
And again, THC is the active component in marijuana.
Troy Walden (01:48):
Correct. It’s the impairing substance in marijuana. It’s the actual ingredient that causes that euphoric feeling that comes with use of that substance.
Bernie Fette (01:57):
So is there any real distinction between those two types of driving impairment?
Troy Walden (02:02):
That’s a great question. I think when you look at alcohol and you look at marijuana, clearly there are two different substances that can impair a person’s ability to operate a vehicle in a safe way, but they’re completely different animals. You know, when you look at marijuana versus alcohol, in terms of impairment, alcohol is what we call the hydrophilic. Meaning that the substance itself goes to the water-rich areas of the body. Something like cannabis, is a lipophilic, which is more fat-centric. It’s attracted to the fat cells. And so what we’re finding is that there are significant differences between alcohol, which is a simple molecule, as compared to other drugs, which are very complex.
Bernie Fette (02:43):
Okay, if they’re so fundamentally different, than does that mean that we should be treating them differently when it comes to prevention or law enforcement?
Troy Walden (02:50):
No, I don’t think we should treat them differently with regard to the enforcement part. I think what we should recognize is that each of these drugs are different, not only in the way that they affect the body, but in the activities and the behaviors that are exemplified by somebody who’s using them. For instance, when we talk specifically about alcohol, you see a very depressant-like effect on the body. You start to see, especially at higher levels, you see un-coordination, inability to perform basic mental and physical activities and those same types of things are consistent with marijuana, but you have more of a mellow, sedated type of person under the influence of marijuana, where with alcohol, depending on what side of the, the curve that you’re on, either going up in BAC level or coming down on the backside, you start to see differences with behavior — more active, you’re more socially interacting, more excited than on the downside of the alcohol, on the back end of the curve, where you’re coming down, you start to see the lethargy, the really solid depressant-like effects that alcohol has on the central nervous system. So there are two completely different types of impairment. But what we really need to consider is that impairment is impairment, regardless of what that individual is under the influence of.
Bernie Fette (04:09):
So, the appearances and behaviors might differ a bit, but the end result is basically the same.
Troy Walden (04:13):
Bernie Fette (04:13):
I know that the crash statistics that you tend to follow in your research, they lag a bit behind and we need at least a few years worth of numbers before we can call something a trend. But what else do we know so far about marijuana use and car crashes or marijuana use and impaired driving arrests, even if there’s no crash?
Troy Walden (04:37):
Yeah. Unfortunately we really experienced a loss in the number of arrests nationally with regard to impaired driving and across the board arrests are down significantly because of COVID and other issues that are happening within the law enforcement community.
Bernie Fette (04:52):
And that’s regardless of the type of impairment?
Troy Walden (04:53):
Regardless, yeah. So we’re seeing a pretty significant reduction in the number of arrests as a consequence, if there’s no swift and certain action, they’re going to make the choice because there’s no real risk of being arrested, right? So they make the poor choice of getting behind the wheel of a car and driving. But, you know, there are some studies that are showing the data suggests that some of the permissive policies that we’re experiencing from just the social changes that are happening within our country, there are different policies that are coming out associated with drug use.
Bernie Fette (05:24):
And you’re specifically talking there about the trend toward legalization of marijuana?
Troy Walden (05:29):
Correct. Either the legalization through compassionate care act and then there’s the recreational use. And there’s a really significant difference between those, Bernie, and I think it really kind of needs to be explored a little bit more. And the fact that individuals who are using cannabis for pain relief. So those individuals who may have a serious condition such as cancer or a young child that has epilepsy, that they’re using the oils in order to stop those seizures from occurring, are completely different than the user who is taking it from a recreational standpoint. So generally what you would see, you know, is those individuals who are taking medicinal cannabis are generally not going to be the ones that are going to get behind the wheel. They’re going to be at home trying to take care of themselves, whereas those individuals that are taking it recreational are more apt to not only get behind the wheel of a car, but also to mix the cannabis with other drugs such as alcohol and increase the likelihood of the opportunity to crash.
Bernie Fette (06:29):
Okay. Keeping that distinction in mind, let’s talk for just a minute about the trend toward legalization for recreational use. Is marijuana-impaired driving a bigger problem in states where it’s been legalized for recreational use?
Troy Walden (06:46):
You know, right now,
Bernie Fette (06:48):
Or does this get back to the problem you mentioned earlier?
Troy Walden (06:49):
The jury’s still out.
Bernie Fette (06:49):
Yeah. You don’t have all the data that you want.
Troy Walden (06:53):
Right. We’d love to have more data. But right now with, you know, states like Colorado and Oregon and Washington that have had recreational marijuana for quite a time, they’re going back in and they’re looking at their crashes and trying to determine whether or not the legalization of recreational marijuana coincides with crashes. They’ve also looked at the combined effect of legalization, recreational use and retail sales and whether or not it coincided with an increase in crashes, injuries, and deaths. And really what they found is that there’s a pretty significant rise in the number of injury-related crashes and fatal crashes that are happening in those states that have legalized. For instance, there was a 6 percent increase in injury crashes and about a two-and-a-half percent increase in fatal crashes in those states that had legalized recreational marijuana. Another recent study showed the combined effects of legalization and recreational use and retail sales also coincided with about a 6 percent increase in injury-related crashes and about a, about a 4 percent increase in fatal crashes. So when you look at not only the, the legalization from medicinal standpoint, the legalization from a recreational standpoint, and then the legalization of retail sales, each of those are independent variables that can be looked at and it shows increases. But when combined together, we find a much greater increase in the number of injury crashes and fatal crashes that are occurring.
Bernie Fette (08:21):
Okay. I want to make sure I understand. It sounds like you and others who are tracking the relationship here between legalization and crash frequency. It sounds like you don’t quite have as many years of data as you would like to make definitive declarations, but you’ve got some early indicators, some hints that there’s a relationship, right?
Troy Walden (08:43):
Right. And clearly we would love to have more data from before and after periods. Clearly the after periods, we’re looking at four to six years with regard to data, the more data that we get, the more robust the findings are going to be, but there are some indicators that suggest that what we’re seeing with these increases are a result of the permissive attitudes that some of the states are having towards a policy of marijuana use in their states.
Bernie Fette (09:10):
And I’m glad that you mentioned attitudes because I know that some of the research that you’ve done at TTI regards Texans’ attitudes about marijuana use legalization and driving. Can you tell us a little about that research and what you see as being the main two or three takeaways?
Troy Walden (09:28):
Yeah, we did some research back in 2018 here in CADES, or the Center for Alcohol and Drug Education Studies. Then we looked at different folks in different opinions within Texas over 25 different counties to better understand, you know, what perceptions they had towards marijuana use legalization and driving. And what we found was kind of frightening and thought-provoking at the same time. One aspect was more than 60 percent of those individuals that were surveyed agreed that it was unsafe to drive after marijuana use yet 89 percent said it was unsafe to drive after consuming alcohol. So if you kind of look at that one little snippet, most of the folks thought it was safer to drive with somebody that was under the influence of marijuana. There was almost a 30 percent difference between them. So that was really kind of frightening.
Bernie Fette (10:17):
To what would you attribute that misconception?
Troy Walden (10:19):
You know, I think a lot of it has to do with street talk as opposed to getting good factual information about the differences between the impairment levels that you would experience with marijuana versus alcohol. So I think that there’s really a kind of a disconnect. Everybody really kind of focuses on alcohol as their gold standard towards impairment, but impairment is different across the use of multiple types of drugs. And so the differences of effects that different drugs give as compared to alcohol are not really comparable. Impairment is impairment across the board, but everybody seems to measure that against alcohol as that gold standard. And unfortunately, I think they come away with thinking, well, I know what I feel like under the use of alcohol. And I know kind of what I feel under the use of marijuana. And I feel a little bit easier with marijuana than I do with alcohol. So marijuana is safer and they just make this assumption that that level of impairment or that type of impairment is better than another. And it’s just not the case.
Bernie Fette (11:21):
While we’re on the subject of attitudes, I’m reminded that in the history of impaired driving in recent decades, there was a decrease in the severity of the problem in the 1980s. And one of the things that happened during that time is an increased amount of activism and a change in public opinion that said that drunk driving was no longer as socially acceptable as it had been in previous times. I’m wondering if part of what is needed to help shift some of those opinions might require a similar shift in public attitudes towards social acceptance.
Troy Walden (12:03):
Yeah. Ultimately I do think that what we’re going to be looking for is some form of a transformational change. I think in order to change how we think about drugs and driving, we’re going to have to have that changed. That comes from some type of a transformational framework.
Bernie Fette (12:18):
What I’ve heard others in your line of work refer to as traffic safety culture.
Troy Walden (12:23):
Sure. Yeah. And there are competing cultures that we’re, that we’re dealing with here. We’ve got those individuals that are traffic safety advocates that are pushing for it for safety component. And then we have the other side of the coin, which is the marijuana industry and those individuals that are pushing for legalization that are pushing for responsible use policies and to relax the thinking behind use. And I think they’re winning out, at least at this point, it’s changing the thought process of those individuals and I think in order for us to be able to make any kind of movement of the needle with regard to traffic safety, we’re going to have to look at how we can best fit the needs for each of those stakeholders. So I don’t know what the answer is to that, Bernie. I really wish I did. That’s the million dollar question.
Bernie Fette (13:11):
What you’re doing now and through your research is looking for answers, which makes me wonder what’s the most important question that you have right now that research could help to answer with regard to this issue?
Troy Walden (13:24):
Well, I think in order for something to change, we’re going to have to create different ways to reach out to the public to better inform them and educate them with regard to the dangers of impaired driving. But we’re going to have to make a more concerted effort towards educating, especially since those that are advocating for responsible use are really pushing their message hard and heavy. And that message is resonating more right now with the public. And unfortunately we started to see some of the results of use, especially in those states that have recreationalized. So I think from a research standpoint, we have to continue to dig into the issues, look at it objectively and look at the good and the bad. Drugs and alcohol aren’t good or evil. They are what they are. But unfortunately, some of the choices that are made by people to consume the drugs and then get behind the wheel of a car and, and attempt to drive, certainly it’s not a good mix. So, you know, ultimately I really think that as a community of researchers, we really need to acknowledge that motor vehicles and roadway safety engineering has made incredible advances. The only thing that we have left is really to change those behaviors. And through our research.
Bernie Fette (14:33):
Before we wrap up, I’m curious about how your previous career might have influenced the career that you’re in now. Did you see yourself doing traffic safety research way back when you were wearing a police uniform?
Troy Walden (14:48):
I, you know, the research that I’m doing now has direct relationship to what I experienced when I was a younger police officer, but, you know, I think seeing the day-to-day interaction with people who are using the different types of drugs and interacting with them and seeing how those drugs impacted their behavioral choices and that experience of dealing with people while they were impaired really helped me to better understand the substances that they were using, but also the behavioral indicators of how that drug made them behave and in turn how it impacted their lack of ability to control the vehicle. But I think ultimately the main thing that I really experienced as a law enforcement officer was just to see the different types of incidences that we would go to and take calls for. And that’s from domestic violence to traffic crashes and a majority of those had alcohol and or other drugs involved with the mix that created that situation, that really kind of spurred the need for law enforcement to be called to the scene.
Troy Walden (15:49):
One story that I could tell you is that I went to a call once says a young officer and a young gentlemen had agreed to take care of his girlfriend’s dog over the Christmas holidays. And she came back and found, you know, her dog hadn’t been brushed properly and hadn’t been taken care of the way that she had wanted to take care of her. And they had been drinking and smoking marijuana and they were having a great time up until that point. Then they began to fight over the dog and he made the choice to go inside, pull out a pistol and shoot himself in the head. And that really kind of opened my mind up towards how the impairing effects of alcohol and drugs, especially in combination with each other, can create something in somebody to do such a thing as take their own life and had that person had the normal use of his mental capacities, I don’t think that he would have pulled that trigger.
Troy Walden (16:39):
I don’t think that that his loss of life, that, that really needed to happen over the care of a dog. So that really kind of opened my eyes up to see how alcohol and drugs can really transform somebody’s thinking into a desperate act. And then of course, you know, with the traffic crashes that I investigated and reconstructed while on patrol, I’ve waded through a lot of blood and guts on the roadway and seeing that alcohol was involved with the majority of those cases, um, it really kind of opened your eyes as to the dangers that alcohol and other drugs have on the choices that people make and how they do make that choice to get behind the wheel of a car and thinking about themselves and not thinking of others and becoming involved in a crash that could and did take their lives or injured others that.
Bernie Fette (17:27):
Could have been avoided.
Troy Walden (17:28):
It could have been avoided.
Bernie Fette (17:29):
Yeah. Powerful stories. Thank you for sharing those. This is my last question. And I think that you may have already, at least partly answered it just in the last few minutes, but what motivates you to keep showing up every day to do the work that you’re doing?
Troy Walden (17:48):
Well, I think our goal as researchers is to improve traffic safety. And ultimately that’s what I think TTI does not only through the Center for Transportation Safety and the Center for Alcohol and Drug education Studies, but overall throughout our entire agency is safety-centric. And so from my standpoint, what drives me is the opportunity and the challenge to change the human condition, to think of others and to help others better understand that their driving actions do come with consequences, you know, be it speeding or wearing a safety belt or gunning it to beat out the yellow light, or using drugs or alcohol. So we have a chance and we have the challenge to change the culture of the me-first attitude. And in changing that mindset, I think we can move the needle forward towards solving our traffic safety problems. That’s really what drives me is the opportunity to be able to make that contribution to the people of the state, through our research and through our efforts of either education or outreach or through the research that we do that informs the Texas Department of Transportation on policy issues. But ultimately that’s our goal and that’s to change behavior and through the change of that behavior to save lives.
Bernie Fette (19:01):
And the rest of us are better for it. Troy Walden, senior research scientist at TTI. Thank you Troy, for helping us understand this issue more clearly. We appreciate it.
Troy Walden (19:12):
Thank you. I appreciate y’all.
Bernie Fette (19:16):
Of all the drivers involved in serious injury crashes and fatal crashes last year, more than half tested positive for at least one drug — some legal and some not. The latest numbers tell us that while driving drunk has become a bit less common. driving high is more prevalent. What exactly constitutes driving under the influence is not as simple as it once was, especially given the constantly changing landscape of state laws. But while the circumstances of impaired driving may have changed over several decades, its consequences clearly have not.
Bernie Fette (19:55):
Thanks for listening. We hope you’ll be back next time for a conversation with TTI agency director, Greg Winfree, and Zach Doerzaph, executive director of the Virginia Tech Transportation Institute, discussing how university-based entities can help to advance transportation research. Thinking Transportation is a production of the Texas A&M Transportation Institute, a member of the Texas A&M University System. The show is edited and produced by Chris Pourteau. I’m your writer and host, Bernie Fette. Thanks again for listening. We’ll see you next time.