Thank you.
We have in the United States, as I'm sure you're aware, for many years now been altering, on a state level, our legal prohibitions about marijuana. We have quite a few states that have passed measures authorizing what's called medical marijuana use. Some of them contain very few restrictions. We've had some jurisdictions decriminalize the use of marijuana, and as you know, now we have eight jurisdictions that have legalized recreational use of marijuana. We are confronting a sea change, and I think the expectations are this will continue over the next few election cycles.
I work in our Department of Transportation, in our road safety organization. I have focused on impaired driving for over 35 years now, on alcohol and drugs, a specialty of mine. We like to be evidence-based.
What can I say about marijuana and driving? I think there is ample evidence from laboratory research, driving simulators, in-vehicle research on closed courses, and even in traffic that marijuana has the potential to impair driving-related skills. It is a psychotropic drug, that's why many people use it recreationally, so I think there's no question it impairs driving. Certainly it does not make one a safer driver, so it's not a good thing from a road safety point of view.
Our ability to actually talk a bit about the crash risk of driving under the influence of marijuana is quite limited at this point in time because of the complexities in conducting that type of research. I know there's a tremendous desire for someone to come up with an impairment level for marijuana, and that really is just not feasible at this time. It's not clear if it will ever be feasible that you will have an analog to blood alcohol concentration or breath alcohol concentration.
People are all very familiar with the alcohol model. It really does not apply much to many other drugs, whether they're prescription or illegal drugs, and it does not apply to THC, where you do not get a correlation with the psychoactive ingredient, delta-9-tetrahydrocannabinol. You can measure blood levels, you can measure oral fluid levels, but you do not see this nice correlation between blood or oral fluid levels and impairment that you see with alcohol.
It is certainly reasonable and feasible for police officers to detect marijuana-impaired drivers, and arrest them, and prosecute them. As I always try to point out to people in our country, research we've done shows that many people in the U.S. refuse to take a BAC test. In many states they have that right, and it may result in the suspension or revocation of the driver's licence. It's almost approaching 25% of the people arrested for alcohol-impaired driving who don't take a BAC test, and the vast majority of those are prosecuted, and successfully. We've compared cases where there is a BAC available to the prosecution, with cases where there isn't, and it results almost in identical conviction rates between them.
The fact that you don't have an equivalent to BAC is not a bar to the successful prosecution. It's important that police receive training in detecting. They need to know how to recognize signs of marijuana impairment. They have to be trained in careful observations and note-taking.
I will agree with the witness who preceded me, Ms. Kelsall. I do think that when you legalize a substance like marijuana, people get a very positive impression, and they think it's safe. They do not realize—just like with alcohol, which is a legal substance—that it's not safe to drive impaired by alcohol, marijuana, or many other psychoactive drugs. It's critically important as part of legalization that the public be informed that impaired driving is impaired driving, whether it's by a legal or illegal substance. There is a lot of education that needs to be done.
I know there is a lot of interest in these oral fluid drug-screening devices. I do think those would probably be useful for law enforcement. I know that in most of the United States there are tremendous backlogs in conducting drug tests. This is a real disincentive for law enforcement to get a blood sample, send it off to a lab, and wait for months—sometime three, four, five, six months—to get a test result. The available evidence right now seems to show that screening devices are fairly accurate. They're not of the same quality as what we would call evidential tests—qualitative tests done at a laboratory—but they seem to be fairly accurate. I would expect to see their use increase over time. I am hopeful that there will be proper testing of these devices before their use becomes too widespread. There have been some studies done to date, but most of those have been funded by the manufacturers, which, of course, are very interested in marketing their devices.
At that point, I'll just stop and welcome any questions you might have.