Establish a fuel CONSUMPTION limit, not a speed limit.

@ Esabre
People in Germany drive very good and that's why they are allowed to go at more than 130 Km/hour in some autobahns.

Double nickel golf cart speeds? Nanny state speed limits? These are the ideas of people who like to go 80+MPH, & don't want tickets for 60 or 65MPH. Even if vehicles weren't as safe as they are keeping the death-rate on our highways down, they would want to keep traveling at 80 MPH unfettered & hang it if some extra people get killed or our country saves some balance-of-payment fuel costs.

My post above clearly tells of the fuel & money savings from taking it easy on the gas pedal. Its hard to change racer boy mentalities. But racer boys sure try to convince us of the 'reasonableness' of their 120 feet per second life-style.

Jorge, how do think that people in Germany ended up driving so well? They didn't learn in a vacuum and were then unleashed on Germany's high speed autobahns.

This is the dumbest idea ever. The government lowers the speed limit and then labels everybody who exceeds it as reckless. There are plenty of cars out there that get better fuel economy at 100mph than our big gas guzzlers get at 55mph. Furthermore, as noted above, the problem is not with our highways. It is that so many people drive to work every day. If we all took the train to work 5 days a week and then drove our cars at 100mph to the beach or the mountains or wherever we want to go on the weekends, we would be using far less fuel than we do now.

I agree with most that the 55MPH speed limit was a bad idea that seldom got enforced. Moreover, I would thought that Warner would know that it didn't work given that he's been in the Senate for so long (Warner became senator in 1979, 4 years after the speed limit law was passed).

Moreover, a better fuel saver is better Mass Transit.

I believe that 55 should once again be considered. They should put RFID readable chips in cars that when a car goes by we can tell what year and model it was at any point on the highway and the older the car the more it should slow down. If its a newer gas guzzler it should slow down. Hybrids or vehicles in general that achieve 80+ miles per gallon should be allowed somewhat higher speeds and all electric vehicles should given as high a speed as the road will allow. If its 100 mph on a nice straight piece of road we should allow the people that can afford it and who spend their money on vehicles that have zero emissions to go as fast as is safe for the stretch of road. If a guy is cruising across the desert in Arizona at 100mph and zooms by me I might be encouraged to upgrade a little sooner if really am bored to death. Lets reward lower consumption with greater speed and not punish everyone just because we are not allowed to drill for oil in this country. The one problem with this thinking though is that the Democrats would be punished for not converting fast enough if they are the poorer group as they claim and the rich Republicans would be able to drive around as fast as they want...so once again...another idea will be squashed by partisanship.

The advantage of an enforced speed limit is that it reduces oil consumption quickly and cheaply. It really can reduce consumption up to 20% on the highway. Assuming 1/2 of all consumption is on the highway then that gives you 10% at no cost (to the govenment). There is some cost but it is minimal in the grand scheme of things. The speed cameras would pay for themselves and may make enough to offset the decline in gas tax revenues.

At 55 - we could also reduce the size of the engines and vehicles a bit easier - with greater public acceptance.

Long term - I personally want to go 80-90. But I'll wait until the fleet converts over to more efficient/alternative fuel vehicles.

Axil, nothing against nuclear but please stop asking for public subsidies. After 60 years of massive funding it's about time for nuclear to walk on its own feet.

Yucca mountain: The repository project's price tag could total in the range of $77 billion http://www.lvrj.com/news/10257277.html

50 billion dollar tax safety net for nuclear industry:
http://www.npr.org/templates/story/story.php?storyId=15545418

Up to 24 billion Dollars for only 2 nuclear reactors. And the consumers are forced by law to foot the bill in advance.
http://www.npr.org/templates/story/story.php?storyId=89169837

China has way more solar hot water capacity than nuclear power, even though nuclear power receives massive subsidies and solar hot water does not.
And nuclear power in China provides only 1.6% of the Chinese electricity demand or less than 0.3% of the Chinese energy demand.

Sorry to put a wet blanket on your nuclear dreams, but these are just simple undeniable facts.

The quickest way to reduce fuel consumption is behavior modification. This is already happening on our interstate highways, where over-the-road trucks are in the process of adopting a defacto 60 mph speed limit. This does not obviate the need to do other things.

When the 55 mph limit was passed, most drivers had grown up during a time of lower travel speeds. My father-in-law's '49 Ford was rarely driven over 50 mph, no matter what the speed limit was. It would be even more difficult to enforce a 55 mph speed limit today than it was in the 70s.

That said, an enforcable limit of 60 mph is doable. Most people cheat on the limit by at least 2 or 3 mph, which would put travel speed at around 100 kilometers per hour, an important point, since that is the speed at which fuel economy really begins its drastic downturn.

A major reason traffic accidents decreased with the 55 mph limit was that all traffic was now moving at the same speed, whereas, previously cars and trucks had different limits. Make a national 60 mph limit uniform, including appropriate rural two-lane roads, and people will get used to that norm.

55 mph is a sorry excuse for corrective measures. Alternative fuels are needed with an urgency of war like attitude. Our congress reps. are too busy with the party line to care for this country and people

@anon Jul 13, 2008 4:09:32 AM

You are absolutely right in everything you say, but hear me with an open mind.

The US nuclear program was wrong from the very beginning. When the light water reactor was chosen as the American nuke (the world nuke), because of the early US navy power plant designs, it was a disastrous decision. It is subject to core melt down with coolant loss, and produces dangerous and long lived waist. All these plants should be shut down.

But

The small gas cooled pebble bed reactor using thorium fuel has these characteristics as follows:

• It is fail safe and cannot melt down (I.E. 100% tested guarantied safe).
• It can not produce bomb material.
• Its waist lasts only 600 years.
• It is 30% more efficient than light water reactors.
• It produces hydrogen at 65% efficiency.
• It can be factory build on an assembly line.
• It can consume waist from the old light water reactors with fuel reprocessing.
• It can produce Biofuel, oil from tar sand, or oil from shale.

Not bearing the burden of the trauma tragically imposed on us by our leadership. China will field thousands of these plants in upcoming years.

They have perfected, tested, and are fielding the first of these plants and the assembly line is being built.

Eventually and without doubt, America will be forced to field these plants to stay competitive in the world. By then, there will be a long and successful operational track record for these nukes from China.

But we will have paid a very high price for the repeated and inexcusable incompetence of our leadership that, I fear, will only be forgotten over many long years and the passing away of our generation.

For me, my dreams will look towards China and wish them well. In China and throughout the world, pebble bed nukes will replace coal. This can do this earth nothing but good.

17% of all fuel is burned in cars moving at 0 mph. The 55 limit saved maybe 2%. If every vehicle had an idle stop hybrid retrofit then 8 times as much fuel would be saved. Providing every car with an mpg gauge or more significantly a miles per dollar gauge would slow down people without any speed limit change.

I'm not a nuclear fan, but I've read that pebble-bed reactors use graphite pebbles (instead of water) to moderate neutron speeds (because slow neutrons are much more likely to be captured and so maintain an adequate rate of fission events).

So, although pebble bed reactors won't melt down like 3 Mile Island, they can burn like Chernobyl...

So is the danger of graphite in pebble-bed reactors negligible ?? Or can you suggest an alternative moderator to graphite ??

Why so much negativity. My impression is that fuel economy deteriorates rapidly at speeds over 60mph. Every little bit helps us buy time.

henry Gib,
I endorse your view that some way be found so that the sale of oil futures and derivatives can't be made to parties who have not the facilities to take delivery. We have to do something to prevent a small group's ability to destabilise a nation. We don't need to be told by those traders, as the recession becomes a depression, " Look, everything we did was legal"
In fact the incentive of futures was to stabilise and guarantee farm incomes, not for the few wealthy oil men who don't need that protection.
I hope that makes sense, else that was yet another magazine article that I read once and thought I could understand....and obviously didn't.

T2

All a lower speed limit will do is cost me more money in speeding tickets and raise sales of radar detectors.

I have things to do. Unlike some people on this board and those making decisions about speed limits, I'm upwardly mobile and have a lot of hustling to do so I can even get to the point where I can even consider being a Sunday driver every day of the week. If I'm late because I get a ticket for a ridiculously low speed limit then it will cost me opportunities. That pisses me off.

I honestly feel that people drive too slow on the highway as it is. You get on the highway to get somewhere faster than city streets in the first place. The reason people drive is because it is faster than walking or riding a bike, period. Forcing people to drive slowly is an unfair tax on the movers and shakers that make America competitive.

As for congestion, I don't see how a 55 limit solves anything. Perhaps there may be fewer wrecks, but the slowdown the wrecks cause is now spread out through the day since the highway is perpetually slower. Wrecks may also increase because more people will weave through a slower traffic flow. There'll still be slowdowns based on congestion, regardless. If you want to avoid congestion then get a GPS that guides you around traffic. I have one and it's great. Saves me on gas too, because I never get lost and drive around in circles looking for something.

If you want to move into a situation where vehicles with poor fuel economy slow down and waste less gas, then perhaps a graduated license system would help. One in which inefficient vehicles are limited to a lower speed or slower lanes than more efficient vehicles. People won't like that because it limits their choices, which is Un-American. Maybe so, but it's pure BS that I have to drive like a grandma because nobody had the foresight to deal with this problem when gas hit $2/gallon.

In short, I don't like it.

55 mph was a death sentence in my neck of the woods, 60 wouldn't be any better. It might work in some areas of the east coast and parts of urban California but not the west. ASU UoA NAU SoCal UoN UoLV UoNM all did studies and all found the same thing. Lower speed limits cost lives in the high sierra.

@JayDee

So is the danger of graphite in pebble-bed reactors negligible ?? Or can you suggest an alternative moderator to graphite ??

Graphite cannot burn in a helium environment. But there is a very low probability (1 in 20,000) that a pebble can be defective. It will deteriorate and leak a small amount of radiation into the helium.

Also, the operating temperature is below the combustion point of graphite.

A flawed pebble has imperfections in the silicon carbide cladding and will be detected and isolated during the constant pebble recycling process. Only if there is a complete coolant failure will the flawed pebble be at risk of rapid decomposition. But the total number of flawed pebbles is small due to very high quality control during manufacture.

Good pebbles are well coated with silicon carbide and cannot burn.

Warner is asking the DOE and GAO to answer the following questions:
1. Given the significant technological improvements since 1974, at what speed is the typical vehicle traveling on US highways today most fuel efficient?

I think Warner and a lot of posters will not be happy with the reply. It's probably in the region of 40 mph.

Anne - right on. I don't know where people got the idea that overdrive negated the laws of physics. Sure it helps but not enough to magically make going faster more efficient.

Whatever the limit is enforcement is the key.

I wonder how people would feel about a temporary speed limit - like 2 years.

If driving slower saves gas, and gas is expensive people will slow down to save money law or not.

On short trips I don't mind taking my time to get better mpg.

On a long trip where I have 100's or 1000's of miles to cover it is just not worth it. The $ savings of driving at 55 vs the speed limit is small compared to the time penalty. If you save $5 in gas but it takes you an hr longer to get there ... isn't your time worth more than that?

@ Anne
The gasoline ICE operates more efficiently at moderate RPMs and significant load.
At 40 MPH -in the highest gear- the load on the engine is very low.
I think most of the gasoline cars provide the highest mileage per gallon between 50 and 62 MPH.

Why can't we just make it harder for people to get a license? Its not a right of this country to drive a car and in my experience most people are just out there aiming the damn thing.

If you were able to get rid of all the people that fail to look down the road and realize traffic is stopped ahead and make a proper lane change, or don't understand how to get on the freeway at freeway speeds so merging without causing a slowdown works, or maybe all the idiots that I have to honk at every day that don't realize that a right turn is typically free, then my guess is the national savings in fuel would also be substantial.

I'm pretty confident a study on that will not come out ever, but I'm sure making old people re-test for their license and increasing the difficulty of the drive test so its not just a mere formality would take a significant number of drivers off road.

@Jorge,

You are right about the efficiency, but the laws of physics are unavoidable.

Aerodynamic drag increases with the square of the speed. The increased efficiency at higher speed does not keep up with the increase in drag.

B.t.w., I made a conversion error (km --> mph) in my post. I think the optimal speed is more in the region of 45-50 mph. Still below the current 55 mph though.