Breaking News
Break Points

Driving and Danger

View Comments: Threaded | Newest First | Oldest First
sixscrews
User Rank
Author
Driving habits/skills
sixscrews   8/16/2016 12:53:53 PM
NO RATINGS
Thanks for the comments on driving - my wife and I drive on I90/94/39 from Madison WI to Mauston WI and back every weekend.  There are lots of idiot drivers on that stretch of the Dwight Eisenhower Interstate highway (and therein lies a tail of supplying the Allied armies in Europe 1944-45) - those of us from Wisconsin notice the Illinoise [sic] plates readily but, on balance, I think the Wisconsin/Illinoise/Other States are equally represented in the speeders, tailgaters, brakers, lane switchers and general dumb drivers.   I have recently taken to picking out license plates of speeders and calling 911 with varying results - maybe one in ten get pulled over by Wisconsin's Finest but at least their license numbers are in the 'system' whatever that is.  As I am, too, of course.

There was a recent article in the NYT that cited a Japanese closed track study of 'peristalsic' traffic flow.  Once a highway gets to its carrying capacity a small change in the speed of one vehicle can propagate for miles as a slow-down.  No need for a tire changer, traffic stop, breakdown, accident to gwak at - just a few flashing brake lights and the whole consort of vehicles can slow by 25%-100% - then eventually pickup again.

When I was a graduate student my fluid mechanics prof had us model traffic flow as if it were two phase flow in a pipe (the banging radiator problem we called it) - amazing how close that came to what I see on the Interstate every weekend.  Plugs of liquid separated by areas of vapor - and this was more than 30 years ago.

Will self-driving vehicles avoid this problem and give us back the capacity of the highway system that is blocked by stupid drivers?  I don't know but I'm not an optimist with respect to technologies - each new one seems to bring with it another set of problems to solve.

But, that's what engineers are for, right?

ss/wb

meterman
User Rank
Author
Driving habits/skills
meterman   8/16/2016 3:06:12 PM
NO RATINGS
Indeed, using an automobile is dangerous. According to the National Safety Council, you odds of dying in a car crash are 1 in 113. Not surprisingly, it is not unusual for us to know somone who was killed in a crash.

The average calandar time between collision claims is 17.9 years. So almost everyone who drives eventually will have a collision.

Cars and roads have gotten safer, and the fatality rates have been on a steady decline since their highpoint in the 1970s. But I do worry about distracted driving. I fear we may see an uptick in fatalities. I so often see cars that can't seem to stay in their lane because of texting.

On my commute yesterday, a guy behind me in a pick-up truck was tail-gateing me. I noticed he had two drumsticks in his hands and was twirling them in his fingers, and dumming on his dashboard and steering wheel. I guess he was steering with his knees. Eventually he passed me on the 2 lane highway, going probably 60 mph in the 40 mph zone. I caught up with him several miles later. He had only advanced one car length.

sixscrews
User Rank
Author
Re: Driving habits/skills
sixscrews   8/17/2016 12:07:07 PM
NO RATINGS
With respect to the fatality rate, indeed the drop is incredible - from 54,589 in 1972 to 32,675 last year.  Even more significant is the rate of deaths per billion vehicle miles traveled - this has been declining since the 1920s - from about about 240 deaths per billion miles traveled in 1920 to under 20 deaths per billion vehicle miles traveled in recent years.

I used to drive late '40s and early '50s trucks - no seatbelts, non-collapsabile steering columns, everything in the cab was hard and, of course, no airbags (although these are a mixed blessing in some [few] situations).  But, compared with some of the mid '20s vehicles I saw over the years these were very safe trucks - safety glass, for one thing, and hydraulic brakes for another.  Handling was also significantly better - drove a Ford Model A around a parking lot once and had a hard time missing trees/light standards/other vehicles - the steering was very heavy and it seemed to be on some kind of autopilot that directed it toward stationary objects.  And the brakes were pathetic - had to stand on the pedal to make it stop.  Got out and told the owner 'don't drive this on the highway.'    

Something to consider is that vehicle manufactuers resisted many of the safety improvements - safety glass was not required until sometime in the '30s, as I recall due to resistance from GM, Ford and other manufacturers.  I also remember the whining about airbags from automakers in the '70s as well as complaints about dual circuit brakes, collapasible steering columns and a host of other things.  Then there is the Ford Pinto debacle - $0.50/vehicle, as I recall, to prevent a significant number of fuel tank punctures from bumper bolts.

Moral of this ramble:  As engineers it is our responsibility to make sure what we design is as safe as available technology can make it - and if we don't do it somebody else will MAKE us do it - provided there are enough bodies piled up...

ss/wb

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed