Cruising Speed

[C5c5]

Originally Posted by Daveinet

Some antidotal evidence. I used to drive every day back and forth to work in Chicago traffic. You would not believe the number of rearend collisions that resulted from a single car going significantly slower than the rest of the traffic. Most of the time the culprit was never involved. Its the accordion effect, where the first car gets slowed down, the second car is able to get slowed down, but skids, and the 3rd car slams into the rear of the second car. I've come close to being rearended several times on my bike. Fortunately I have been able to squeeze between the lanes to avoid getting hit. I also rarely travel in the center lane, as you have very few options when everyone slams on their brakes.

The solution to avoid the accordian effect is very easy and it works: do not tailgate.

The reasons people give for getting into accidents at high speeds can be avoided by making sure you have lots of space between you and the vehicles ahead.

There was a 4 car pile up on the interstate just ahead of me when I was coming home from work a few years ago. I saw it happen live and was the primary witness. I avoided being the 5th in that pile up because I had lots of space between me and the last one of them. We all were going the same speed. If I was "keeping up with traffic," I would have been the 5th. The accident started between the 1st & 2nd cars, when one slammed into the other trying to switch lanes. Cars 3 and 4 smashed into them because they were too close to make any productive evasive moves.

[Daveinet]

Originally Posted by C5c5

The solution to avoid the accordian effect is very easy and it works: do not tailgate.

The reasons people give for getting into accidents at high speeds can be avoided by making sure you have lots of space between you and the vehicles ahead.

This true, but impractical in many cases. In Chicago, it is impossible to not tailgate. If there is space in front of you, someone will immediately fill it and you will be tailgating the guy who just cut in. Its always a compromise of trying to keep enough distance between you and the guy in front, but making the space small enough to not get filled.



Even with light traffic, you can't do anything about the cars behind you.

[Gordon Dewald]

Originally Posted by Daveinet

You know I always find these things as a little confusing. Up until about 15 years ago, the primary cause for accidents was driver inattentiveness. Then all of a sudden it changed to speed. So what changed? Did our driving habits change? Probably not. So that change sounds suspicious. I read your comment carefully, and you state that many times the speed was listed as exceeding the speed limit. I think that statement gets to the crux of the change. A very high percentage of the traffic exceeds the speed limit. So since nearly all cars are speeding, then virtually every accident that occurs will have a car exceeding the speed limit. This makes it very difficult to show any association with speed as to a cause or even contributing factor as a statistic.

The underlying belief is that the insurance companies are behind this statistical change. They are known for supplying sophisticated monitoring tools for catching speeders. Why would they do this? Well because they have an excuse to raise the rates without incurring any corresponding liability. Its been going on for long enough that everyone just excepts it for gospel without challenging the methodology for collecting data.

There was one common item besides speed in these accidents. These were all fatal accidents. One or more people died.

Some were single vehicle, some multiple, some on straight road and some on curves. The majority were on straight roads.

A caveat is I managed a district where the density of traffic was quite low. I can only imagine what occurs when densities are very high.

Would it have been fatal if the speed was slower? Maybe not chances may have been better.

[C5c5]

Originally Posted by Daveinet

This true, but impractical in many cases. In Chicago, it is impossible to not tailgate. If there is space in front of you, someone will immediately fill it and you will be tailgating the guy who just cut in. Its always a compromise of trying to keep enough distance between you and the guy in front, but making the space small enough to not get filled.



Even with light traffic, you can't do anything about the cars behind you.

Dave,
Believe me, I've driven through rush hour Chicago many times and agree it is much harder! As every car passes me and goes in front, I just slow down enough to get the space back. It also means driving at a more steady speed instead of ebbing and flowing with traffic. I find that when traffic is bumper to bumper, it is much slower and therefore better to slow down in an emergency.

Basically I mimic the semi-truck drivers who generally leave a good amount of space in tight traffic.

Agreed there is very little one can do about those behind you, which is why you concentrate on defensive driving as best you can.

I guarantee though that a good majority of accordian pile up accidents could have been avoided by more space & paying constant attention to it.

[C5c5]

Originally Posted by Daveinet

Its always a compromise of trying to keep enough distance between you and the guy in front, but making the space small enough to not get filled.

I'm genuinely curious, why would a careful driver want to keep enough distance to avoid the space in front of them from getting filled?

Why would I want to control someone else's driving like that? If they want to get in front of me, go ahead! Why would I try to control that?

[Daveinet]

Originally Posted by C5c5

I'm genuinely curious, why would a careful driver want to keep enough distance to avoid the space in front of them from getting filled?

Why would I want to control someone else's driving like that? If they want to get in front of me, go ahead! Why would I try to control that?

Its about maximizing the space in front of you. If there is too much space, the space disappears because another car fills the space, so you end up with less space. Ironically, I usually drive in the right hand lane in heavy traffic, as that lane always seems to move faster due to less traffic density. Everyone thinks they want to be in the left lane, so the left lane has more traffic and thus drives slower.

[Gordon Dewald]

My observation is if you drive about 5 under traffic flow the space in front of you will always be expanding. True people will cut in as the space expands but it will get bigger almost immediately after their lane change.

Worse is when they force their way in to a non expanding or contracting space. I let them in and watch them go.

No surprisingly by staying in one lane with a steady pace I will occasionally catch up with a lane cutting, accelerating and braking vehicle.

[Doug427]

I guess George Carlin was correct when he said:



"Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?"

[Cloud Dancer]

It's about survival. So, just be absent from the location where the accident will occur. It takes a very experienced, and very good driver who knows how to anticipate an accident that's about to happen. I call it "accident" instead of the unspoken appropriate name.
I believe that the ratio of good drivers to substandard drivers will remain the same. Therefore, It's still about survival.
IMO a person who tells me that cruising at 65 mph is more dangerous than cruising at the speed limit (or faster),........is wasting their time. Afterall, I'm the one driving. See what I mean?

[Daveinet]

Originally Posted by Cloud Dancer

...
IMO a person who tells me that cruising at 65 mph is more dangerous than cruising at the speed limit (or faster),........is wasting their time. Afterall, I'm the one driving. See what I mean?

65 is a very reasonable speed when the speed limit is 70 and cars are doing 75. I don't have a problem with that. I do have a problem with someone going 50.

[C5c5]

Originally Posted by Gordon Dewald

My observation is if you drive about 5 under traffic flow the space in front of you will always be expanding. True people will cut in as the space expands but it will get bigger almost immediately after their lane change.

Worse is when they force their way in to a non expanding or contracting space. I let them in and watch them go.

No surprisingly by staying in one lane with a steady pace I will occasionally catch up with a lane cutting, accelerating and braking vehicle.

I have found this out too which is why I do not participate in the constant lane changes just to get ahead.

I've seldom had problems maintaining a good amount of space ahead of me, even with lane cutters.

Studies done on traffic patterns have shown that slowing down to make space ahead of you for lane changers does not significantly extend the time it takes to get to your destination. It evens out in the end.

[lonfu]

Originally Posted by C5c5

I have found this out too which is why I do not participate in the constant lane changes just to get ahead.

I've seldom had problems maintaining a good amount of space ahead of me, even with lane cutters.

Studies done on traffic patterns have shown that slowing down to make space ahead of you for lane changers does not significantly extend the time it takes to get to your destination. It evens out in the end.

At 50mph all I have to do is laugh at the silly decisions that the lane changers make. Always more entertaining around the big cities.... It takes me no longer time to drive the distance because I do no braking.

You can always tell who is the inexperienced driver is, they are the ones that are tailgating and lane changing trying to get an open lane....

3/2/2020..... 11.1 mpg.... 3126B cat 29k lbs FL chassis..... I pass them all the time at the gas station. I get nearly 300 miles per tank farther than the fast drivers....

Watched a 40 ft pusher pulling a jeep rubicon at the AZ border on the I40. Have a couple of seismic heaves in the road there.... Coach went up and came down hard, jeep was airborn.... Had to be stuff coming out of the cabinets to the floor.... good news, the blue ox tow bar held!!!! guess they are tougher than I thought... no big deal for me...

[trispeed]

70 to 75 in my 2005 Airstream Land Yacht 26 with GM 8.1 litre gets 9 mpg

https://www.youtube.com/watch?v=XcgX2DkGHds

[RELHUB]

Originally Posted by Farkey

Being new in the RV world I have numerous questions and here is my latest.

At what speed do you people usually cruise on an interstate highway?

I travel at about 60mph because the previous owner said that was the best speed for fuel economy and he would average 12 MPG on a trip.

On my last trip of just under 500 miles, I tried to cruise at 60mph and at the end I got 8.2 MPG. Now mind you that was through the hills in the Finger Lakes, but still getting almost half of what he did.

Unfortunately, I can't ask him any questions because he passed away just after selling me the rig.

So I will be very appreciative of all what you have to say on this subject.

Thank you

1. Some people will tell you they drive 90 MPH or more and want to go faster if they could. I keep it around 65 mph.

2. You will NEVER see 12 MPG and I would bet the MH on it.
Even if you are driving down hill most of the way still will never get 12 MPG. Most people do not know the correct way to calculate this.

It is very simple make sure you START with FULL a tank of fuel.
Record your STARTING MILES and keep all fuel tickets for your trip.
At the end of your trip just before you park it FILL it up again.
As you started your trip with a FULL TANK so you need to park it FULL.
Record your FINISH MILES and add up all of the GALLONS purchased.
Do not forget the gallons for your last fill up just before you park it.

TOTAL MILES divided by TOTAL GALLONS purchased = MPG

Now I take it to the next level just because that is what I do.
My reports for each trip also include:
1. Location of each fill up Date and Time.
2. Distance traveled between stops.
3. Number of hours the generator is used START to FINISH.
I then calculate the hours used @ 1/2 gallon per hour. I will then deduct the number of gallons the generator used to give me a better indication of the MPG for the MH.