Ride share services like Uber and Lyft are now pretty much ubiquitous. It’s so easy to get a ride these days one would think that the incidence of car crashes due to drunk driving should be declining, right?
Well, nobody knows for sure. But the group at Tulane decided to look at their own data for alcohol-related car crashes over a seven year period. They also combed regional traffic databases for more information and compared the data from pre- to post- arrival of ride share services.
Here are the factoids:
- There were 1474 patients involved in alcohol-related crashes (ARC)
- The proportion of alcohol-related ARCs decreased significantly from 39% to 29%
- The overall annual incidence of fatal ARCs seen at Tulane decreased significantly from 11.6 to 5, and also decreased significantly within the region
- However, the incidence of ARCs only decreased within the 21-24 year age group(!)
My comment: This is very interesting work! The statistics appear to be sound and the number sufficiently large. It shows that it might be possible to decrease drunk driving injuries using methods other that the usual prevention efforts. It is puzzling, though, that the effect is only seen in a very narrow age group in the population. Practically everyone can use a ride-hailing app these days. Even I do!
Here are my questions for the authors and presenter:
- How do you explain the very narrow age-range that appears to be affected? Remember, this study shows an association, not cause and effect. Could it be that something else is reducing alcohol-related crashes in this specific age group, and it has nothing to do with ride share availability? What else could it be?
- How can this decrease in 21-24 year olds hold when there was such a significant decrease in overall alcohol-related crashes? Was everyone driving around New Orleans in that age group? Otherwise, how can this be explained?
I am fascinated by this study. But it’s going to be difficult to separate out other confounding variables and causes to be able to point definitively to any benefit from ride share services.
Reference: Do ride sharing services affect the incidence of alcohol-related motor vehicle collisions? EAST Annual Assembly abstract #22, 2020.
The Governors Highway Safety Association released a study that sifted through 350 scientific papers dealing with distracted driving. They summarized their analysis in a nice report that can be downloaded here.
There are 4 types of distraction:
- Visual – looking at something other than the road
- Auditory – listening to something not related to driving
- Manual – manipulating something other than the steering wheel
- Cognitive – thinking about something other than driving
Smart phones provide all four modalities! About two thirds of drivers report using a cell phone while driving, and 7-10% were observed to be using one at any given time. About 12% of drivers admit to texting while driving, and about 1% of drivers are texting at any given time. At least one driver is reported to be distracted in 15-30% of car crashes.
The following items were gleaned from the papers reviewed:
- Cell phone use increases crash risk, but the exact amount is not known
- Hands-free cell phone use has not been shown to be safer
- Texting increases crash risk, but the exact amount is not known
- Hand-held phone bans reduce use somewhat
- Texting bans have not shown any significant effect, although high visibility enforcement campaigns offer some hope
Syracuse NY and Hartford CT enacted high visibility campaigns (“Phone in one hand, ticket in the other”) in late 2010 and spring 2011. They found that cell phone use dropped by half, and texting dropped 72% in Hartford and 32% in Syracuse. These results do not agree with the GHSA findings, most likely because of the intensity of the efforts in these two cities.
Bottom line: We all know that texting while driving is bad and cell phone discussions while on the road are not very good either. There may be some utility to enacting bans on these activities. However, given the other responsibilities of our police departments, enforcement will always be a lower priority. Engineering solutions like roadway rumble strips can help divert attention back to driving, and crash investigations should aggressively examine any contributions to driver distraction. Ultimately, we’re going to have to treat this problem like we do for driving while intoxicated, with stiff penalties and driving restrictions. Unfortunately, I don’t think we’ve got the fortitude to do it anytime soon.
Download: GHSA Report on Distracted Driving
What Happens When An Axle Snaps
The Ford Windstar minivan is being recalled to deal with a design defect in the rear axle. Here is NHTSA analysis video of what happens when the axle separates. The read of the car begins to steer in random, different directions. This makes the steering wheel nearly useless. Note how the professional driver in this video is saved from a rollover by the attached stabilizer bars.
There are generally about 30,000 deaths from car crashes each year. An analysis by the AAA shows that drowsiness is a factor in about 1/6 of them! In the early 1990’s, NHTSA looked at this problem and found only about 4% of fatal crashes were due to sleepiness.
What gives? Is everybody suddenly a lot sleepier these days? It’s actually due to the way it is reported. As you can imagine, it’s difficult to figure out if fatigue was the cause after the fact in a fatal crash. The driver certainly can’t tell you.
AAA looked at crash rates and applied information it obtained from a driver survey it administered. They found that 41% of drivers admitted to falling asleep behind the wheel at some point. And one in ten admitted to it happening in the past year. The AAA believes that their estimates are far more accurate than the lower NHTSA numbers.
Sometimes our patients tell us that they think they may have fallen asleep at the wheel. You should assume it in anyone who is driving home after a long shift, especially early in the morning.
Educate your patients about the warning signs of fatigue while driving. Everyone knows the obvious ones: droopy eyes, frequent daydreams, drifting in and out of lanes. But here are some of the not so obvious:
- Difficulty remembering the last few miles driven
- Frequent yawning
- Restlessness, irritability or aggressiveness
- Frequent scratching and rubbing
Once fatigue becomes a factor, the driver is not only a danger to themselves, but to everyone else on the road as well. The solution: pull off as soon as practical and call for assistance. Caffeinated drinks are overrated and take too long to work!
Sources: American Automotive Association, NHTSA, National Sleep Foundation