Will the 55 mph speed limit be reintroduced?

[K1052]

Originally posted by: Tab

Originally posted by: CycloWizard
As I have been saying in this forum for almost 4 years now, the key to beating high gas prices is an investment in improvements in our dilapidated rail system. Trains are much more cost-effective than are cars. However, we have become myopic and won't make a substantial capital investment for very significant long-term savings.

I've always been curious as to why we don't have a high-speed rail system. Of course we've got to deal with Earthquakes but I don't think that'd be impossible to deal with.

Expense and until relatively recently the low price of oil.

A national high speed rail network (180-200mph) styled on the TGV/Eurostar type equipment would cost hundreds of billions to construct and operate. Though regionally it is starting to make a lot more sense to use rail and Amtrak's ridership is reflecting that.

 

[Throckmorton]

Originally posted by: K1052

Originally posted by: Tab

Originally posted by: CycloWizard
As I have been saying in this forum for almost 4 years now, the key to beating high gas prices is an investment in improvements in our dilapidated rail system. Trains are much more cost-effective than are cars. However, we have become myopic and won't make a substantial capital investment for very significant long-term savings.

I've always been curious as to why we don't have a high-speed rail system. Of course we've got to deal with Earthquakes but I don't think that'd be impossible to deal with.

Expense and until relatively recently the low price of oil.

A national high speed rail network (180-200mph) styled on the TGV/Eurostar type equipment would cost hundreds of billions to construct and operate. Though regionally it is starting to make a lot more sense to use rail and Amtrak's ridership is reflecting that.

We don't need 200mph interstate lines, although they'd be a good thing. What we need is intracity rail networks, including suburbs. Compare the cost of rail with highways, and then on top of that factor in the costs associated with automobile commuting.

 

[Uhtrinity]

Originally posted by: CycloWizard
As I have been saying in this forum for almost 4 years now, the key to beating high gas prices is an investment in improvements in our dilapidated rail system. Trains are much more cost-effective than are cars. However, we have become myopic and won't make a substantial capital investment for very significant long-term savings. I like driving as much as anyone, but the current American lifestyle isn't sustainable. The oil companies have found out how inflexible we are in our demand and have raised prices accordingly. Demand hasn't changed much at all since I started driving 11 years ago, despite a quadrupling in the price of a gallon of gas.

I did a fairly extensive economic analysis on all cars costing less than $25k after my car died. At current gas prices, the Yaris, Fit, and Elantra were close to the bottom of annual costs. The Prius and Civic Hybrid, which are the only two cars that get anywhere close to decent gas mileage in this price range, are marginally more expensive. If gas goes up to $5, which my projections indicate is the equilibrium cost when oil is around $110/bbl, then the cost of owning a Prius becomes almost equal to the cost of owning even the subcompacts because their mileage is still pretty bad (32 tops for the Yaris IIRC). As the cost of gas increases, the Prius becomes the only viable option with the Civic Hybrid lagging behind due to higher cost, worse mileage, and higher insurance premiums. So I put down a deposit on a Prius this weekend.

Sadly, the mileage of the Prius (estimated at 45 mpg combined) is still pretty poor compared to a lot of cars in the 60's and early 70's. The addition of catalytic converters and other downstream processes to eliminate NOx and COx from exhaust has compromised the efficiency of engines and added dramatically to the complexity and maintenance costs of these cars. If we lightened up on these requirements, gas mileage would soar with minor environmental impact. If we release 100 pounds of exhaust at 1% pollutant concentration to go 100 miles or 50 pounds of exhaust at 5% pollutant concentration to go the same distance, which is really worse? The latter releases less CO2 but more NOx and COx, while the former burns more gas and releases more CO2. *shrug*

With some modifications of your driving habits the Prius can easily do 10mpg or more better than the epa numbers. My parents just bought one over a month ago on my recommendation and easily beat epa numbers.

 

[K1052]

Originally posted by: Throckmorton

Originally posted by: K1052

Originally posted by: Tab

Originally posted by: CycloWizard
As I have been saying in this forum for almost 4 years now, the key to beating high gas prices is an investment in improvements in our dilapidated rail system. Trains are much more cost-effective than are cars. However, we have become myopic and won't make a substantial capital investment for very significant long-term savings.

I've always been curious as to why we don't have a high-speed rail system. Of course we've got to deal with Earthquakes but I don't think that'd be impossible to deal with.

Expense and until relatively recently the low price of oil.

A national high speed rail network (180-200mph) styled on the TGV/Eurostar type equipment would cost hundreds of billions to construct and operate. Though regionally it is starting to make a lot more sense to use rail and Amtrak's ridership is reflecting that.

We don't need 200mph interstate lines, although they'd be a good thing. What we need is intracity rail networks, including suburbs. Compare the cost of rail with highways, and then on top of that factor in the costs associated with automobile commuting.

Many major (top 10 or so) cities already have commuter rail and a number of smaller ones are building services.

 

[Robor]

Originally posted by: IGBT
..I expect rationing to return. even/odd. Raising the driving age to 21 is also on the horizon.

Put a cap on driving age while they're at it.



Hey, I live in FL.

 

[Fern]

Not too long ago there was a ststistic published about how a 55 mph limit would save enough oil to offset that imported from the middle east.

While I can understand that cars today may have a different *sweet spot* than 55 mph, I have no objection to finding the right limit and making it law if it will help substantially.

But at some point you get diminishing returns with this type of program alone; China and India will be stepping to pick up the slack in demand. If the engineers can find the right speed limit, that's good start, but only a start. We need more.

Fern

 

[miketheidiot]

Originally posted by: IGBT
..I expect rationing to return. even/odd. Raising the driving age to 21 is also on the horizon.

no and no

 

[miketheidiot]

Originally posted by: Throckmorton
We don't need 200mph interstate lines, although they'd be a good thing. What we need is intracity rail networks, including suburbs. Compare the cost of rail with highways, and then on top of that factor in the costs associated with automobile commuting.

actually 200 mph interstate lines are what we need first, they cities that need short distance mass transportation generally already have the systems.

they main reason why we don't have a large highspeed rail network is that the initial start up cost is enormous, and without a full rollout to a large portion of the top 50-100 msa's, its not really worth much since the airlines can already get just about anywhere in comparable time frames.

That said, a full rollout would probably cost less than the it would to rollout the current aviation system or interstate highway system.

 

[EagleKeeper]

Originally posted by: K1052

Originally posted by: Throckmorton

Originally posted by: K1052

Originally posted by: Tab


I've always been curious as to why we don't have a high-speed rail system. Of course we've got to deal with Earthquakes but I don't think that'd be impossible to deal with.

Expense and until relatively recently the low price of oil.

A national high speed rail network (180-200mph) styled on the TGV/Eurostar type equipment would cost hundreds of billions to construct and operate. Though regionally it is starting to make a lot more sense to use rail and Amtrak's ridership is reflecting that.

We don't need 200mph interstate lines, although they'd be a good thing. What we need is intracity rail networks, including suburbs. Compare the cost of rail with highways, and then on top of that factor in the costs associated with automobile commuting.

Many major (top 10 or so) cities already have commuter rail and a number of smaller ones are building services.

Commuter rail will work when there are core targets/corridors for the users to get to.
Many cities have highways that fall within that critera. Right of ways exist that light rail can be run on. Put bus stations and/or train stations at key intersections/destinations.

 

[Throckmorton]

Originally posted by: Common Courtesy


Commuter rail will work when there are core targets/corridors for the users to get to.
Many cities have highways that fall within that critera. Right of ways exist that light rail can be run on. Put bus stations and/or train stations at key intersections/destinations.

Makes me want to play Simcity 4... Everything I know about urban planning I learned from one hardass Welsh professor, and remember by implementation in Simcity 4.

 

[OutHouse]

Originally posted by: IGBT
..I expect rationing to return. even/odd. Raising the driving age to 21 is also on the horizon.

What the hell for? there is no gas or oil shortage and no reason to ration.

wow some people in here are just plain stupid :roll:

 

[K1052]

Originally posted by: miketheidiot

Originally posted by: Throckmorton
We don't need 200mph interstate lines, although they'd be a good thing. What we need is intracity rail networks, including suburbs. Compare the cost of rail with highways, and then on top of that factor in the costs associated with automobile commuting.

actually 200 mph interstate lines are what we need first, they cities that need short distance mass transportation generally already have the systems.

they main reason why we don't have a large highspeed rail network is that the initial start up cost is enormous, and without a full rollout to a large portion of the top 50-100 msa's, its not really worth much since the airlines can already get just about anywhere in comparable time frames.

That said, a full rollout would probably cost less than the it would to rollout the current aviation system or interstate highway system.

The total price tag always makes people crap bricks.

California is going to have their $10B high speed rail bond for a LA to SF route on the ballot this year, we'll see if the fuel prices loosen up the voter's purse strings with respect to rail investment.

 

[IGBT]

Originally posted by: Citrix

Originally posted by: IGBT
..I expect rationing to return. even/odd. Raising the driving age to 21 is also on the horizon.

What the hell for? there is no gas or oil shortage and no reason to ration.

wow some people in here are just plain stupid :roll:

..in the liberal paradigm it's principal over people.

 

[fornax]

Originally posted by: b0mbrman
Yeah. Doesn't resistance increase exponentially relative to speed?

No, as the square of the speed.

 

[charrison]

Originally posted by: CycloWizard

Originally posted by: charrison
I highly doubt this is the case. Above around 50mph, wide resistance because a huge factor. The rule of thumb is for every 10mph faster you go, it costs you 4mpg.

And where did you learn that, some wonderfully insightful CNN article? Give me a break. "Rules of thumb" which are linear (as is the one you suggest) are useless in the case of turbulent boundary layers because they obviously neglect every factor that was used by an engineer somewhere upstream to arrive at the 4 mpg figure. If your rule of thumb was true, then some cars would actually get negative gas mileage above 90 mph. So please, keep your rules of thumb to yourself and go take a class on boundary layer theory rather than getting all of your information from some BS online news article.

Well actually it was not a CNN article, but it was from a similar news source. But since I know a little more about physics of moving a car at that speed, it seems to be quite the reasonable rule. This of course is no replacement for actual real world test or doing a specific calculation for your car(most people would not even know the required data to do the calculations).

From wikipedia

The power to overcome air resistance increases roughly with the cube of the speed, and thus the energy required per unit distance is roughly proportional to the square of speed. Because air resistance increases so rapidly with speed, above about 30 mph (48 km/h), it becomes a dominant limiting factor. Driving at 45 rather than 65 mph (72 rather than 105 km/h), results in about one-third the power to overcome wind resistance, or about one half the energy per unit distance, and much greater fuel economy can be achieved. Increasing speed to 90 mph (145 km/h) from 65 mph (105 km/h) increases the power requirement by 2.6 times, the energy by 1.9 times, and drastically decreases fuel economy. In practice, rather than doubling or halving the fuel economy, the difference is actually closer to 40-50%, because engine efficiency varies greatly with the torque/speed operating point. Rolling resistance, which is broadly proportional to speed, is also a factor particularly at lower speeds.

So if you think there are cars that get the best fuel economy 70 or even more incredibly at 90, I sure want to know about them. I am sure the auto industry wants to know as well.

But here is what speed typically does to fuel economy
linkage

At 90mph, most of these cars are close to 50% of their mpg at 50mpg.

 

[CycloWizard]

Originally posted by: charrison
Well actually it was not a CNN article, but it was from a similar news source. But since I know a little more about physics of moving a car at that speed, it seems to be quite the reasonable rule. This of course is no replacement for actual real world test or doing a specific calculation for your car(most people would not even know the required data to do the calculations).

So if you think there are cars that get the best fuel economy 70 or even more incredibly at 90, I sure want to know about them. I am sure the auto industry wants to know as well.

But here is what speed typically does to fuel economy
linkage

At 90mph, most of these cars are close to 50% of their mpg at 50mpg.

Rayleigh's formula is great for enabling simple calculations, but it is hardly representative of any real car's aerodynamics. The formula assumes inviscid flow (i.e. air has zero viscosity) and implicitly assumes certain things about the geometry of the car which are not satisfied by any commercially available car that I am aware of. Further, it assumes that the particle is traveling through a medium which is infinite in all dimensions, which is obviously incorrect since a car is fairly close to the road.* I'm not arguing that it's a bad rule of thumb, but it has to be used in the proper context, as with all such expressions. Computational fluid dynamics and wind tunnels are really the only way to get at the real values. So, if you think you have developed an analytical model that predicts drag better than Rayleigh's formula, you could get a job working for an automotive company in about three seconds. And you can keep your graph which looks like it was made by a third grader. I have 11 years of fuel economy data for my old car that I can plot just as easiliy, but what's the point? Each car is different, and these differences depend on a lot of factors that simply aren't included in Rayleigh's analysis. If they were, aerospace engineers would largely be out of a job.

edit: *This can be corrected for analytically, but only in the case of a sphere by using Faxen's law.

 

[SigArms08]

Reducing speed limits to 55mph is hardly a solution, though, and it would be ill-received. How about giving GM some credit for their approach to solving the issue at hand? http://www.businessweek.com/au...5/trash-to-fuel_g.html

 

[marincounty]

How about no speed limit in the fast lane? That's what I'm proposing.
And the 55mph limit was signed by Nixon, hardly a liberal. The California motorcycle helmet law, signed by Pete Wilson, also not a liberal.

 

[OFFascist]

I wouldnt support such a law but I do voluntarily choose to drive 60mph to save gas.

 

[piasabird]

The argument for larger cars for safety is self defeating. The larger they build cars for safety, the more even larger cars you need to build for even more safety. This borders on insanity. It is like when you buy a fishing boat and then decide you need a bigger and bigger and bigger one. You dont really need a bigger boat, but you have to have it.

 

[teckmaster]

Even if the Federal Government enacted some sort of 55MPH law, there is a lot more to it than just saying the maximum speed can be 55mph at the most. The reason why most states are above 55mph is because this is one issue where currently, state law superseeds Federal law. I know you get down into Texas and the speedlimit on the highways is 80MPH.

 

[EagleKeeper]

Originally posted by: teckmaster
Even if the Federal Government enacted some sort of 55MPH law, there is a lot more to it than just saying the maximum speed can be 55mph at the most. The reason why most states are above 55mph is because this is one issue where currently, state law superseeds Federal law. I know you get down into Texas and the speedlimit on the highways is 80MPH.

The Feds have a big stick w/ respect tothe speed limits.
If the limits are not lowered (if the Feds "request" it), Fed funds to the states related to the transportation infrastructure can be reduced.

Way back when in the original oil crisis, the Feds had the speed limits reduced to 55.
States that did not comply initially, had DOT funds reduced.

 

[seemingly random]

Bunch of old women here advocating low speed limits. Life must be over.

 

[umbrella39]

Increase the speed limits. I could sleep in an extra 10 minutes if they were 80.

 

[glugglug]

Something else to think about:
The new R-134 freon that they use nowadays, since R-12 was made illegal by the enviro-nazis, is 2.5x less efficient, so 2.5x more gas is needed to run the A/C (how is this environmentally friendly?) On a typical vehicle today, over 30HP is eaten by the A/C. For a small car, that's more than is being used to keep the car moving at 75mph. The slower you go, the longer you end up with the A/C running, and the more fuel you will use.