I think that this theory is valid. Based on my knowledge of greater Midwest driving and Chicago driving (I-94,80/90, Eisenhower etc) 75MPH is a normal, average speed.
Of course, there are millions of different scenarios that would invalidate it.
Speed really does not matter. I drive as fast as the situation will allow anywhere from 10 to 100. I learned how to drive in Chicago highway rush hour traffic, at 75 miles an hour. (Driving my mother no less.)
Here are the Top 10 Rules that have helped me drive as fast as I can but stay in control:
The most important thing is to stay ALERT. This is much more than “not driving distracted.” Driving is a full time job, there is never a time to relax, ever.
Give way when needed.
In addition to yourself, pay attention to every other vehicle on the road. You can predict a lot of stupid maneuvers by watching others drive.
4)If you don’t know the road, you have no idea how fast to drive. Error on the cautious.
When it comes to driving, INDECISION killed the cat. Go or don’t go, never hover in between. (Someone behind you is driving 75 on there way to Chicago!)
Weather always wins. Don’t fight it.
On the highway, don’t stare at the car in front of you. By the time they are braking, it’s too late. It’s the 3rd or 5th car ahead of you that is about to ruin your day.
You are driving the car, the car is not driving you. If you don’t feel in control, you are not.
Maintain your lane when turning onto any road. No 2 or 3 lane wide swings.
Never, never, never drive on the East Coast. Those people are nuts!
You think you make sense with “Here are the Top 10 Rules that have helped me drive as fast as I can but stay in control:”
I can only tell you that we were impressed also with this simple idea while taking police academy driving instruction. The faster you go, the bigger the cushion you need around you, front back and to the often neglected sides.
As conditions reduce traction, the same applies. At some point, driving on the salt flats is really the only safe place for some to drive at higher speeds. I’m NOT impressed by people’s admonitions of their “superior” driving abilities at higher speed and how “in control” they say they are.
Like in warfare, when traveling at higher speeds EVERYONE is at greater risk and tragic results can come unexpectedly, chaotically and W/O warning to even the well prepared and “in control” you think you are. You have less and less control over the other guy invading your space as your speed increases;traveling at speed makes you increasingly vulnerable.
First, it’s spelled “theorem” and it’s NOT a theorem. Second, raise the speed to 1,000 mph. That’s called reductio ad absurdum and I’m using it to defeat your counterargument, Mountainbike.
I have to agree with you on one thing, there is NO published data and NO detailed studies. NONE. None whatsoever. None.
[b][i]Mr. Woof, At What Point Does Breaking Distance Become Proportional To The Square Of Braking Distance ? Is Breaking Distance The Distance Beyond The Necessary Braking Distance Needed To Avoid A Collision ?
Braking distance is indeed proportional to the square of the speed. I found braking distances from 60 MPH and 100 MPH in a few exotic car reviews on line. The distances were proportional to the sqare of the speed in those tests. Since they were not trying to prove this hypothesis, the data is objective. And it means that if someone is going 55 MPH they will stop in the distance it takes someone travelling at 78 MPH to reach 55 MPH. Approach that slow driver with caution.
I lived by Indy for the last 9 years and I found that the traffic flowed at about 10-15 mph above the limit normally, a littlr faster at rush hour. It works as long as we all do it. 465 goes around Indy with mostly 3 lanes, and is used by the commuters. We are supposed to keep in the right lane except when passing. We usually move over to let a merging car in. This squeezes most of the traffic into a jam in the right lanes. I find it safer here to go faster in the left (fast) lane, and avoid the jams. There are many places like this where you have to adjust what you are doing to local conditions.
The key word was proportional the formula very well can show relationship between stopping distance and speed squared for example if I were just to squared the speed and divide by 21 I would come close to the real braking distances. Note I just use the breaking distance not the total with reaction time.
15 mph = 10.7 ft real life 11 ft
20 mph = 19.0 ft real life 19 ft
25 mph = 29.8 ft real life 30 ft
30 mph = 42.8 ft real life 43 ft
40 mph = 76.1 real life 76 ft
50 mph = 119 real life 119 ft
55 mph = 144.0 real life 144 ft
60 mph = 171.4 real life 171 ft
There are other charts out there and depending on the deceleration they use might have slightly different numbers, but you can change the number you divide by and remain very close to the braking distance the speed is still squared.
I live in Cleveland - Chicago is about 300 miles away. If I drive to Chicago averaging 60 mph, it will take me 5 hours. If I average 75 mph, it will take 4 hours. Unless the risk of an accident is 20% higher at 75 mph than at 60 mph, then 75 mph is safer, because I will only be exposed to the possibility of an accident for 4 hours, not five. During the 5th hour of driving required at 60 mph, I won?t be on the road; I will already have reached my destination.
I’m willing to bet that you can’t successfully average 75 mph on that trip. In order to do that, you’ll have to be driving 100+ mph for most of the way and not have to stop to refuel or pee.
Jeez, no wonder our jobs are getting offshored. If it’s on the internet, it must be true, so this is now on the internet, just the like the reviews you didn’t cite.
“The braking distance is proportional to the square of the speed.”
At 1 mph, braking distance would be 1 unit, at 2 mph it would be 4 units, at 50 mph, 2500 units, at 75 mph, 5625 units, at 100 mph, 10000 units.
Let’s call the “unit” an inch, just for the sake of reducing the argument to absurdity. You’re telling me braking distance at 50 mph is 208 feet?
Well, let’s see. Full tank of gas, check. Drain unneeded fluids before leaving, check. Prostate on loan from God, check. According to Google Maps, it’s 343 miles, all on the interstate. I don’t think you’re exaggerating, I just think what you say makes no sense whatsoever. Also I would suggest you review your math.
Are you aware that in the 1960’s or 1970’s two writers for Popular Science set a U.S. coast-to-coast record of about 45 hours, in a station wagon, never speeding (of course speed limits were higher then)?
You’re simply wrong. If he can’t average 75 mph then he can’t keep up with traffic.
Are you aware that in the 1960’s or 1970’s two writers for Popular Science set a U.S. coast-to-coast record of about 45 hours, in a station wagon, never speeding (of course speed limits were higher then)?
In other words, they averaged about 61.7 mph. You don’t define coast to coast but it’s about 2777 miles from NYC to LA on I-40.
Freeways were also a lot more free flowing in those days. Every minute of time lost hitting a traffic backup takes a minute of going twice the average speed to make up, or two minutes going 1.5 times the average speed etc. I’ll take a free flowing route over one with high speed limits any day.
Get a trip computer that tracks moving and overall average speed and see for yourself just how hard it is to average 60 mph on your next long road trip.
It’s nice to be able to play with numbers…but just to prove to myself how “fickled” they are w/o considering all the factors, I’ve done the following. I have a 4 hour trip to visit the kids that we frequently make over exclusively highway and can engage the CC more than 75% of the time. I use cruise when ever possible, usually set to 70 mph.
Occasionally, out of boredom, I make the entire trip with the cruise set to no higher than 57 mph. The trip log shows and average speed increase of much less than the 13 mph indicated and a loss of less than 20 minutes on average of overall driving time. There are just so many other factors working, that reduction of speed average subjectively, does not decrease trip time as significantly as one might think.
My conclusion is as usual…obeying the speed limit and driving safely does not cost the the driver the kind of time penalty worth considering as opposed to the increased dangers in driving too fast. I agree that the difference in speed is greater and keeps me reluctantly from doing it more often as cars wiz buy at much greater speeds. This forces me to reevaluate “keeping up with the flow” vs driving slowly. When towing though, I have little choice but to travel much slower.
I can see the validity in both points of view. Everyone’s experience is just too situational to make these arguments valid without an agreed to set of parameters.
“… and the force involved depends on the speed of the object with which you collide.”
Maybe indirectly it does, but only if the other vehicle’s speed causes your car to stop more quickly. If both cars are moving at a constant speed, only negative acceleration occurs as they stop. Very quickly. But it’s not that easy. Mass is very important, too. I think momentum rules in this case.
It’s nice to be able to play with numbers…but just to prove to myself how “fickled” they are w/o considering all the factors, I’ve done the following. I have a 4 hour trip to visit the kids that we frequently make over exclusively highway and can engage the CC more than 75% of the time. I use cruise when ever possible, usually set to 70 mph.
You said 75% of the time, did you mean to say 75% of the distance? There’s a big difference. I agree with your conclusion that high top speed is over-rated when it comes to maintaining a high average speed. It’s the stopping and slowdowns that kill you. Freeways are fast more because they don’t have red lights or a several mile long 30 mph speed zone for every small town you go through more than they have high speed limits.
Here’s an interesting quiz.
Joe drank too much at the bar and so someone gave him a ride home. The next day, he decides to walk to the bar to get his car.
He walks to the bar at 2 mph. How fast does he have to drive home to average a 4 mph round trip?
If you gave 6 mph as an answer, you are probably one of those people who thinks he is averaging 70 mph just by keeping up with the traffic.
The correct answer is that it is impossible to drive fast enough to bring the average speed up to 4 mph, he would already have to be home when he reached the car.
Funny, is it not, that everyone drives like they are on their way to a fire on the freeway but you almost never see anyone run to their cars as fast as they can run. How everyone complains about slow speed limits but nobody complains about how long it take for a gas pump to fill the tank.
The record average speed for the Indy 500 is 185.981 mph set in 1990. Don’t those guys drive 220+ mph for most of the distance? It just goes to show what pit stops and yellow flags do to your average speed.
So which part of my counterargument do you think you’re defeating, the part that says as you go faster limitations to avoid accidents like limited visability, deteriorating ability to control most vehicles at high speeds, and the need to react faster as you go faster make high speed more dangerous?
Or perhaps you think you’re defeating the comment that differences in speed creat turbulance in the flow of traffic and can cause accidents?
Or are you just the self-anointed local spelling cop now? Or did you just want to show us aome of your latin?
Dude, the fact that you found a spelling error and used latin does nothing for your argumment. Whatever your argument is in this case, which is conveniently not included in your reply to my post. The only content I see in your post is a terse criticism of my spelling and a latin phrase.
Occasionally, out of boredom, I make the entire trip with the cruise set to no higher than 57 mph. The trip log shows and average speed increase of much less than the 13 mph indicated and a loss of less than 20 minutes on average of overall driving time. There are just so many other factors working, that reduction of speed average subjectively, does not decrease trip time as significantly as one might think.
I have done my own experiment with fast verses slow driving. I have a 37.1 mile commute from work to home and most of the distance is highway and interstate with only about 1.7 miles of suburban street driving on the final part of the trip. About 15 miles of the trip is a highway with traffic signals and everyone goes 60-70 even though the speed limit is 55. About 13 miles is interstate with 65 and 70 mph speed limit. The rest is interstate style limited access highway that’s not called an interstate highway.
I used a Garmin n?vi navigater GPS unit to keep track of my speed and compute the average speed and trip time.
Driving like a complete jackass and risking a ticket:
Maximum speed: 93.1 mph
Overall average speed: 42.1 mph surprised it’s that low? So was I.
Moving average speed: 50.7 mph
Moving time: 43:58
Stopped time: 9:04
Total time: 53:02
Taking it easy:
Maximum speed: 63.6 mph
Overall average speed: 38.9 mph
Moving average speed: 42.3 mph
Moving time: 52:37
Stopped time: 4:36
Total time: 57:13
53:02 vs 57:13 that’s only a four minute and 11 second difference in a nearly one hour trip. Yet most people who drive like complete jerks think they are getting there twice as fast as the people who take it easy.
Well said. My Garmin was in full agreement. Gee, isn’t that an additional 4 minutes and 11 seconds being exposed to a potential accident ? BTW, that was a very subjective 75% “time” at lower speeds and much less at higher. I’ve found the mental fatigue was significantly different as a result.
BTW, that was a very subjective 75% “time” at lower speeds and much less at higher. I’ve found the mental fatigue was significantly different as a result.