So, are we driving too slow?

[sushidogchip]

I think the premise is flawed. Sknight, you are ignoring a basic principle of logic. One cannot infer from the general to the specific, only from the specific to the general. In other words, one can't say "because I drive a certain speed compared to the stats I am either safer or less safe." As has been stated, there are many complex factors affect safety on the road. It's like the "guns at home" argument that statistically your family is more likely to be shot by a family member than an intruder if you have guns in the home. That may be true for the general population, but not for a disciplined family of trained, sober gun owners who secure their weapons and behave responsibly. Now I'm not trying to change the subject or go off on another tangent, only using this example to point out this flaw in logic. It's like saying that since young black males are statistically involved in a higher percentage of crime relative to their percentage of the population, that we can infer that somehow a certain young black individual is more prone to commit a crime. This is obviously absurd (or should be.) But you would be surprised at the number of folks that get caught in this logic trap on a variety of topics.

My rule of thumb is to drive a little slower than you feel safe, stay alert and when the traffic gets heavy or road conditions deteriorate slow down even more, regardless if others are flying by, irregardless of the legal speed limit. Next month I'll be going on a vacation and have chosen my route carefully avoiding interstates as much as possible. I plan on traveling up the Natchez Trace which has a 50mph speed limit and prohibits commercial traffic (no big trucks, but RVs are cool.) On the opside, I'll save a lot of gas, though I plan on a 12hr day of driving - which some consider an unsafe behavior due to fatigue and inattention. Since I will be excited to go on vacation and will be leaving well rested, and since I am used to driving long hours in my job, I think my risk of fatigue and inattention from this 12hr drive will be less than most. Ah well, you roll the dice and take your chances.

Chip

[Brandonrv]

I could maintain close to 70 in my short 27' winnie class A. In my new 36' though heck no. Even if I wanted to maintain 70 in this big thing it would be tough unless I was driving on perfectly flat road with no incline what so ever.


at 64 though it cruises right along and my knuckles stay a healthy shade. Most places the interstate is 75 in Texas now so people are going to just have to get use to going around me.

[BCooke]

For the studies. Was the Kloden one missed? Summary being "Risk of being involved in an injury crash was lowest for vehicles traveling near or below the median speed and increased exponentially at higher speeds"

[JFXG]

Originally Posted by BCooke

For the studies. Was the Kloden one missed? Summary being "Risk of being involved in an injury crash was lowest for vehicles traveling near or below the median speed and increased exponentially at higher speeds"

I think the Kloeden study would not be held relevant to our discussion. 1) The data is over 15 years old; 2) the study focused on a road segment with a 60 km/hr speed limit. That's 37mph-- neither highway speed nor highway design; and 3) the study was conducted in Australia, not the US. More specifically, the study applies directly to 60 km/h speed zones within the metro area of Adelaide, SA.

Apart from the broadest connections based on general human nature, I see no applicability here. So many particular cultural factors contribute to driving behavior, analysis must be somewhat localized. You could hardly, for example, conduct traffic studies in Riyadh and Rome, and apply the results to Rochester.

[Gadget63]

We are never in a rush to get anywhere and we feel most comfortable between 60 and 65. The sweet spot for our Bounder seems to be 63 mph where we get our best mpg.

[BCooke]

Would you consider: Methods and Practices for Setting Speed Limits, Federal Highway Administration, Report date April 2012. "The safety effectiveness of differential speed limits for trucks is inconclusive." Somewhat relevant?

[Capt Steve]

Whichever side of this argument you are on the simple fact is the law is quite clear. Speed limits are not suggestions and they only apply in good weather (clear, dry, not windy etc.). If you choose to exceed the speed limit your action is criminal and you are negligent, period. Everyone knows this but the "Laws are for everybody else crowd" will always have a self serving rationalization at hand.

If you do not like the existing laws than work within the system to get them changed. I doubt there are too many (if any), folks here that have the level of expertise that the folks who write the traffic laws possess.

[BCooke]

The other question that comes to mind on speed differential, for me is based on my years in EMS.
True story...
Picture a car accident on a major interstate, north bound facing north, at approximately 2:30 pm on a slightly overcast day, state police with all flashing lights and auxiliary raising rear facing warning lights in the left lane, blocking the left lane, for EMS protecting, being struck be a vehicle going, at minimum, the speed limit of 55, in such a fashion that the whole trunk and part of the rear seat was no longer recognizable. The trooper was life flighted.....
...sorry, got it speed differential. Some times the driver needs to realize it is not slot cars.... my opinion of course.
I have been stuck behind, we have a 2 mile hill that a truck doing 45.1 mph tries to pass a truck going 45 mph in a 65 zone. I have also been the one going 10 under.
For those of you that can remember..... what it use to be like. I can remember my father in a converted bread truck doing 10 mph up hills across the UP (Michigan).

[Mike and Cha]

Steve, you are right on point. This topic is very simple yet got overly complicated. Statistics will work for you whichever way you want depending on what side of the issue you stand on. The bottom line is it's not the crash that kills you "it's the sudden stop at the end" that kills you. Add in all those IDIOTS that drive 15-20 mph(or more) over the speed limits while talking/texting on their cell phones then you have a much better chance of the "sudden stop at the end" type crash. You can only control what happens ahead of you to some degree, but never whats behind you.

When we are driving rigs like we have we are usually on vacation, so drive safely, keep your eyes on what is going on ahead of you (not to say checking your mirrors frequently for upcomming vehicles is not a good thing). Remember It's all about the journey, not just the destination. So enjoy it. And by the way I have worked on a few committees where we have written/and or changed some traffic laws in our state....Mike

[BCooke]

Mike and Cha rattled something else loose, sorry.
I also added more lights to the rear of my 5er. When asked why, non RVers, I tell them so people can see my trailer.

[sknight]

Originally Posted by sirpurrcival

Well actually you have.

"We're not talking about speeders. The actual issue is when people drive far below the posted limit thus causing a dangerous situation. Traffic regularly flows 5MPH over the limit I don't care if it's 25 or 75. There will always be the 10 over crowd, and there's always that guy pulling down 20 over. Everybody hates him. But the average is around 5MPH over."

Although 5mph is really nothing to get excited about, it is speeding.

So on balance, do you believe that there is a greater % of people driving significantly under the speed limit so as to be a danger to traffic or a greater percentage of people driving significantly over the posted limit so as to be a danger to other traffic?

Statistics showed in 2009 that approximately 20% of drivers were exceeding posted speed limits by greater that 10 mph. 45% by 5 to 10 mph and a whopping 71 percent were speeding 0-5 mph. If a 15 mph hour differential is critical in affecting traffic safety, I would respectfully suggest that the bigger problem is created by the majority of drivers who are speeding at least part of the time. I say this because in 20% of states (and I put RV's in this category) trucks have a slower posted limit. If a truck is driving the posted limit which is 10 mph slower than for cars. Then that means 71 % of car drivers are close to if not exceeding that 15mph speed difference by virtue of their speeding.

Furthermore "too slow" is very poorly defined. If there is a posted minimum, then of course, drivers need to achieve that mark. If not, in many instances it becomes much more a judgment issue. Judgment based on conditions, type of vehicle, ability to let traffic pass and so on. In many cases, a too slow violation is given because someone is:

A. driving in the overtaking lane for no good reason (turning left would be a good reason)
B. failing to let faster traffic pass by using designated pull outs

To be sure, driving too slow can certainly result in unsafe conditions and accidents but where is the proof that these are more common and dangerous than accidents caused by excessive speed? 55 mph is certainly a reasonable speed for many RV's. 60 if conditions are good and some newer rigs are good at 65 and maybe even higher. A brief survey of threads showed that most RV's admit to going no slower than 55 and most around the 60 mark or a little above. As mentioned earlier, these units are heavier, less maneuverable, harder to stop and much more subject to unseen hazards such as wind gusts. They are different vehicles that require different driving behaviors. If you want to make a case that they shouldn't be on certain roads because they are inherently too slow...well, that isn't going to go too far.

At the end the day, RV's are involved in far fewer traffic fatalities than your standard auto and on balance would put my faith far more in the statistically safer group. I would put most RV drivers in the highly conscientious group. That is doing their best not to inconvenience those trying to go faster and/or driving in such a way as to create hazardous conditions. But as an RV'r, I will draw the line at having someone in a Volkswagon try to dictate how fast I should drive an 11000 kg RV with awesome destruction potential if I do the job badly. If I am going 10-15 mph below the limit, there is probably a good reason for it and it is my own council I will take until someone who is entitled to tell me to do otherwise does.

But where did I suggest we exceed the limit with our rigs? I didn't. I have stated that traveling far below the speed of traffic is dangerous, studies have shown that to be true.

While extreme, a very visual example is auto racing. When running in close quarters and one car starts slowing down you can clearly see the effects of other cars swerving around the slower car.

I repeated what studies have shown. Apparently not clearly and at this point will stop.

[sirpurrcival]

Originally Posted by sknight

But where did I suggest we exceed the limit with our rigs? I didn't. I have stated that traveling far below the speed of traffic is dangerous, studies have shown that to be true.

While extreme, a very visual example is auto racing. When running in close quarters and one car starts slowing down you can clearly see the effects of other cars swerving around the slower car.

I repeated what studies have shown. Apparently not clearly and at this point will stop.

You don't state it outright and not to beat a dead horse, your point is that going too slow can be a dangerous situation. Granted. However if the majority of traffic is setting a speed that is neither practical nor safe to do so for a larger RV then what is the expectation? By far and away, RV'rs are responsible, practical people. They drive at a rate of speed which is commensurate for their particular brand of vehicle. If other vehicles with far different driving characteristics HAVE to go significantly faster, well then it is on them to do so safely. If they are running into slower drivers, they either are going too fast for conditions, failing to pay close enough attention to the traffic and failing to leave themselves sufficient room to maneuver. A bit simplistic perhaps but most RV drivers are not driving that slowly and statistics show that large proportions of drivers are in fact exceeding posted limits by significant amounts. Whose driving behaviours should we be more concerned with? A relatively small proportion of drivers who may in fact be driving too slow or a large group of drivers who drive vehicles in excess of posted limits. In truth both are a hazard but one far outweighs the other in commonality.

[tedgard01]

Originally Posted by sknight

... While extreme, a very visual example is auto racing. When running in close quarters and one car starts slowing down you can clearly see the effects of other cars swerving around the slower car. ...

First, you can go ahead and talk, no problem. Debate is important for resolving any difference in openion. We need to listen to each other and try not to take things to a personal level. I sometimes do pontificate....

I am visualizing your example. I do understand the concept.

Unfortunately, reality does sometimes mimic this "extreme" example, especially when in rush hour in a larger city...

I would hope that most drivers are not driving on the freeway like they are auto racing, but we all know some do. You are correct that if someone is driving like they are in an auto race on the interstate, it is very likely that there will be bad consequences when someone else has to slow down, and they are suddenly confronted with a large unmovable object just in front of them, not participating in the race...

Therefore, I am sure you would agree that it may be good for both the drivers to consider each other. For those that want to drive like they are racing, if they drive a bit more conservatively, and more defensively, by leaving adequate distance to allow them time to react, that is good. Those that need to slow down need to be aware that someone may be driving too closely, therefore they need to drive defensively and leave adequate room to slow down slower, over a greater distance, allowing the person in the back of them time to react.


Ted

[JFXG]

Originally Posted by Gadget63

We are never in a rush to get anywhere and we feel most comfortable between 60 and 65. The sweet spot for our Bounder seems to be 63 mph where we get our best mpg.

Gadget, the fact is I do the same thing-- I set the cruise at 1750 RPM, and that yields about 63-65mph. It's simply the most efficient way to run it.

What most of the posters seem to have overlooked is that neither the video nor any other posters here are insisting that you must go fast. They've simply advanced the point that everything runs smoother (and more safely) when all the vehicles are within a tight speed envelope. The salient points are two:

1) the great preponderance of drivers (approx 80%) will drive on the highway at the speed they're comfortable with, regardless of the posted limit. No one is claiming that they all drive at 80mph all the time. The fact is that most drive near the speed limit most of the time. But there are some stretches of highway- and we all know of some- where everyone seems to go a lot faster, for a variety of reasons that all boil down to the fact that most people are comfortable driving faster on that road.

2) highway traffic is a living, flexible, dynamic thing, and it flows most efficiently when all the pieces stay aligned and run at the same speed. Lane changing and speed differentials contribute only negative factors to the efficiency of the flow. This is borne out not only by highway design principles, traffic research around the world, but also by the basics of fluid dynamics.