No speed limit, a fuel limit.

Ok, I'll admit this is a crazy idea, not likely to ever see the light of day, but it's worth throwing out as an exercise. It is often said we should keep the speed limit low to encourage good fuel economy.

What if there were no speed limit, but instead a "fuel limit." For example, 2 gallons of gas per hour.

If you are driving a 30mpg Honda Accord, you
could thus go 60 miles an hour, as that would burn 2 gallons in one
hour. If you had a 50mpg Toyata Prius, you could go 100 miles/hour
because that would also burn 2 gallons/hour. ZEV? As fast as you
want, just like Germany.

Bad news in that 20mpg Ford Explorer 4WD. 40 miles/hour maximum speed
for you.

A Hummer? Forget it, you'll be below the minimum speed. No highway
driving for you. Enjoy the side roads.

This is more an academic exercise, as the voters would reject it (they
love their big cars) and we actually don't want anybody going 40mph on
I-280. But in fact, if the limit is set to encourage good fuel economy,
this would be the way to do it. A simpler, but also unpopular way
would be to tax gas to $5/gallon. It's fair, because when you crud up
my air by burning your gas, you owe me something, and the least you could
do is reduce my taxes.

Now of course if you really did something like this it would be more complex. Probably not linear, nobody below 50mph. If 50mph is not enough, an 55mph exception for commercial trucks, busses and other non-passenger or many-passenger vehicles. Being a carpool would also alter your speed. Of course it would be a fair bit harder for cops to enforce, but actually not that hard. Cops are trained to identify cars very quickly, and of course would have a quick database. But frankly, you can tell a guzzler when you see one, most of the time.


There are, of course, more reasons for speed limits than fuel efficiency. Theoretically, they also save lives.

The reason for speed limits is to keep cars from crashing into other cars, people, cows, and stationary objects. Basing speed limits on fuel efficiency not only radically impossible to enforce reliably, and therefore an encouragement for cops to do selective enforcement, it's really a combination environmentalist socialism and anti-SUV greed. If you want to be an environmentalist socialist, it's much more practical to just use artificially high gas taxes and let citizens make their own decisions about whether to deal with gas efficiency by driving at economically optimal speeds or by making fewer trips.
Also, if you want to be a good Progressive, you need to remember that some rich people drive low-fuel-efficiency cars because they like ostentatious consumption, but many poor people drive them because they can only afford older cars which tend to get lower mileage, or they drive vans because they're Workers, and taxing those people heavily is Evil Regressive Taxation.

Why 2 gallons per hour? how about 1 gallon? that way many cars could drive faster. But this idea is irelevant from beginnig - how to mesure fuel consumtion on the road? Imagine 3 carsgoing on the highway: Explorer going 60 mph, Accord going 120 mph and Prius going at 90 mph. How could police know wich one burns proper amout of fuel for it's acctual speed? This is realy a ecological bulshit, Brad.

Instead just drop all speed limits on freeways and highways with seperated lanes for both directions. That way a new tandency would occur: with time drivers would prefer more economical vehicles thus greater range and lower total cost. Give driver what was taken form them!

Generally it's good that someone thinks of such solutions like yours. But the same way you could propose to "one man in a car" drivers to go by motorcycle. Very fast, economical and safe when you know how to ride them. But this road goes nowhere. It's hudrogen time, Brad!

Good Luck!


one problem "Apnea", a fuel cell car, which runs on hydrogen uses fossil fuels and oil. To make hydrogen, you need both of these. Therefore, you're still eventually going to run out of oil and much needed fossil fuels. Thank you and have a good day.

You can actually use electricity to free hydrogen from h2o (aka water), which you can then use to produce electricity to drive your car. Ergo, find clean, renewable electricity sources to power your hydrogen production, and you have no worries about fossil fuels. And you have a tank of drinking water when you run out of hydrogen in your car. There's an experimental hydrogen pumping station in Iceland where you can fill up such a car, so don't go saying it can't be done.

Problem is our clean renewable energy production is fully utilized already, in fact we still burn fuel to make most of our electricity except in a few areas, so the only way to make this hydrogen a clean fuel is to build more renewable energy production. Right now you put more demand on the grid, you cause more fuel to be burned. That can still be more efficient, but for hydrogen there are better approaches cracking oil, I have been led to understand.

Since you brought up Germany already; they do it right. Create speed limits only in areas with a bonified reason (noise reduction near towns or special facilities, road damage, construction, known high accident areas). Everywhere else, let natural factors influence the well-trained operator in reaching a sound decision as to the safe operating speed. At the same time, though, set a recommended speed limit of 80 mph. In the case of an accident, anyone driving over that speed can be held at least partially liable for damages caused; but, if there is no accident, no problem. Everyone goes on about their lives.

I prefer to limit drivers to Kinetic Energy limits to save lives.

For instance, a regular van (6000 pound "conversion" van) rear ending at Pontiac Sunfire (3000 pound) at 60 mph on a Fox TV program obliterated the hatcback area, crushed the right rear passenger seat, and dropped the roof down on the drivers side so far the driver would have to be contortionist to survive. The car was literally tossed forwards, spun around, and tossed off the roadway. This can cause secondary impact with vehicles and pedestrians, who would be crushed by a 3000 pound Sunfire.

On the other hand, a 450 pound sport bike, aka crotch rocket, at 60 mph will only dent in the rear panel, and pop the trunk lid open, and the car wouldn't move forwards at all. Nobody gets hurt but the motorcyclist, and there's no punishment for suicide, is there?

Therefore, why give a speeding ticket to the crotch rocket? What's the crime? It certainly isn't multiple homicide, like the van would be liable for.

Curt Tricarico

Trust me crotch rocket wont be going at 60 mph but 160, what would be that outcome?

the outcome of the crotch rocket going at 160mph still would not injure the passengers of the car. it is almost certain death for the motorcyclist but no injury for the passengers of the car.

So going by what the last two guys said, how about a speed limit based on the weight of the car. Say seimtrucks and buses can go max 60mph, trucks 75mph, compact cars or sport cars 90mph, and bikes 115 mph. And this will also benifit the envioment because every one will try to use a smaller vehicle and smaller uses less fuel!

A direct rear end collision of a sport bike into a small car may very likley kill the occupants of the car as well as the bike.
A side impact of a bike on car accident at that speed often tears the car down the middle
Plus traveling at excessive/dangerous speeds would be considered endangerment to others as well as ones self.
Endagering ones self can get you arrested under mental hygene codes if the speed limits dont get you lol.

I like my sport bike and I like excess of 100mph. But its not reasonable to say a sport bike traveling at high speeds isnt dangerous to anyone other than the Driver.

And how this thread started. gallon per mile? why not tax by mile traveled! if you have a fuel effiecient vehicle you might drive more and you should owe everyone because you are getting more use of the road.just thought I should throw in another idea that makes no sense.

Are you all from CAli or somthing:)

The 2 gallon/hour limit is a novel post in USA context, however impossible to enforce, other than by categorisation per vehicle manufacturers technical data release. But here is the question: why is enforcement, and consequent civil fines such a desired property in US? ** On the same note, my proposal: it is allowed to "roll a STOP sign", if you vehicle mass is less than 3000 pounds. All SUV's, busses, large vans, lorries, trucks make COMPLETE stops - the small car owners only need to YIELD to other traffic -- saving both gas & time.

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