Influencing Busy Four-Lane Highway/Freeway Speeds to Increase FE

[Frank Lee]

I have no faith in the average motorist therefore I think you'd need to block all lanes to keep people back there and "slow". Not a good plan.

[gone-ot]

...can you say "O.J.Simpson-slowspeed rolling blockade?" Sure you can.

[Christ]

Originally Posted by NiHaoMike

If there's a group of hypermilers, how about have at least one in each lane driving at the limit such that it is impossible to pass? I remember reading about a group actually doing that and video recording the results.

I've done a "staggered formation" setup with some friends before, just to see what happened. Guess what? Every driver on the road turned into Tony Freakin' Stewart, weaving around us all like morons, flooring it to get into the other lane, then braking heavily as they approached the rear of the next car in that lane, then flooring it to change lanes again, etc.

Me, on the other hand, when people used to block the highway and go slower than the speed limit, I'd just pass them on the shoulder, usually in third gear, high RPM, as smoothly as though I'd just executed a normal pass under normal circumstances. They normally figure out that I'm passing on the shoulder, and end up swerving toward their "friend" to avoid the perceived accident situation. Often, in the rear view mirror, I see that afterward, they decide that they should fall in line like everyone else, and stop blocking traffic.

I don't feel like it's unsafe to travel in the left lane slower than everyone else, especially after traffic builds up. I do feel that it's completely discourteous, though.

[newhavenpatriot]

Found that video again on Youtube... it was made in 2007 by some students from the Atlanta metro area. This really demonstrates how instead of a traffic jam, you get clear sailing up ahead, and all the cars are going 55, so there is no problem with traffic flow. Unless of course you consider not being able to go faster than the speed limit a problem. I don't.

http://www.youtube.com/watch?v=kuM2A...layer_embedded

[Doofus McFancypants]

I remember the news stories about the traffic thing
Local news had several "irate" people on talking about how this impacted thier day - "Late for work" / "MIssed an oppoitment"
Umm..
1st of all - in ATLANTA traffic - you ASSUME there will be an accident and it will take you twice as long to get where you need to be - so the SPEEDLIMIT should NOT cause to be late - ever.
2nd of all - if you are leaving at a time where you have to speed to get there - you are an idiot.

Was a great event.
I do not recall if the charges of "rolling roadblock" were dropped or not...

I think they could have protected themselves better with a rotating car formation.
have 4 cars passing then pulling over and re-passing . this way no 1 car is "blocking the left lane" and causing a roadblock. you are actually passing the car on your right... he just re-passes you ( with a few blocker cars behind you....

Steve

[dwtaylorpdx]

I worked a project several years ago doing core analysis on LA traffic patterns.

The goal was to determine what the primary cause of traffic stalls were.

After 2 years of analysis and simulation testing despite all the preconceived theories, the major cause of traffic jams and accidents was determined to be cars going 10 miles an hour or more UNDER the speed limit. Cars that were speeding and causing accidents were in excess of 30 miles an hour over the limit and accounted for < 1 in 40 accidents and delays. The split was something like 15% for speeders 55% were slow drivers the rest was mechanical failure or stupidity..

And the 55 magic number is pulled out of thin air. There is nothing magic about 55.
My BMW gets peak mileage at 65 not 55. (34MPG to 36 MPG depending on the terrain.)
Drops to a consistent 30 to 32 mpg at 55. I still get 30 MPG at 75, My state the limit is 65 and I don't save significant time by going to 75 for a < 300 Mile trip so 65 it is...

On the other hand WA lets me go 75 and when its a drive from Portland to Spokane thats 400 Miles and Its all flat, I let the car find its sweet spot and that's usually approaching 75. I tend to exploit the terrain, turnoff the cruise down hill and let it coast up.

Portland to Spokane About 400 miles.
5.3 hours at 75,
6.2 at 65
7.5 at 55

I balance the time against the fuel cost, 45 minutes, not a big deal 2 hours gets my attention, I'm usually working and that travel time is 200 bucks an hour.... vs about 1 gallon of gas. 65 Being the min because I'm not going to lose the time AND the mileage.
I fly when I can but there is a lot of distance between airports in the west and the small towns with no air service.

At the end of the day economics control a lot....

Dave

Side tidbit, the CD of the BMW 318ti is about .34 stock.
The engine is a 1.8 liter with a 5 speed transmission car weighs in at about 2800.

[Frank Lee]

I'd like to know what it is about that car that gives it better fe the faster it goes

[Christ]

Originally Posted by Frank Lee

I'd like to know what it is about that car that gives it better fe the faster it goes

Lots of guys on some of the Minivan forums I'm on are claiming better FE at 62-65 than 55 as well, and it's understandable, because they're geared to hold in the most efficient RPM range at those speeds, since many of the highways have 65 and 70MPH speed limits. Many of those same people are using scan gauges, as well.

This isn't to say that they wouldn't be getting better mileage at 45 than 65, with the transmission locked, but FE curves don't specifically follow speed, either.

Of course, another part of it is that most of the people "trying" to get better mileage by going slower, may just be very squirrely at that speed, since they're used to driving faster, and perceive that they're doing something that could be potentially dangerous.

Of course, I have to add that re: slow people causing traffic jams, that's all well and good, but why did the slow people cause the traffic jam? Because they created a bottle neck when others tried to pass them? Yeah, that's what I thought... therefore, it's not the fault of the slow drivers entirely. Your study, thus, was flawed. From the data gathered, I have to wonder if there wasn't some agenda behind it, as well. Something irks me about it, not sure what.

[rmay635703]

Originally Posted by Frank Lee

I'd like to know what it is about that car that gives it better fe the faster it goes

There are a couple oddballs like that, it may have more to do with how he drives at different speeds or possibly because the slushbox is too slushy at 55 or even because his big motor is choked off too far at 55 who knows.

Or it might even be because of another reason.

[Frank Lee]

side tidbit, the CD of the BMW 318ti is about .34 stock.
The engine is a 1.8 liter with a 5 speed transmission car weighs in at about 2800.

Small engine, no funky slushbox weirdness.

I have my doubts that even if the engine has a better BSFC at 65 vs 55, that that is enough to overcome the added loads.