Comments on: Germany Considers Slowing its Autobahn to Curb Emissions

By: tapra1

tapra1 — Thu, 15 Mar 2012 11:38:22 +0000

while the Social Democrats have proposed a 130 kph number. German carmakers are fiercely opposed to any further taming of Autobahn's thrillingly.Best UK Hosting

By: Dom

Dom — Mon, 11 Apr 2011 14:10:41 +0000

I’m not arguing the fact that slowing down improves fuel economy… I know that is true… though how much depends on the vehicle being driven. Seeing as most Europeans already drive fairly fuel efficient cars (especially their diesels which still get pretty decent fuel economy while cruising at high-speed), slowing down from 80 to 55 isn’t going to see the same savings as say slowing down a full-sized SUV from 80 to 55 here in the US. Besides, they’re talking about emissions not fuel economy, which though related are sometimes at odds with each other with regard to regulations.

But all that said, sometimes it is worth it to the individual to get worse fuel economy to get to a destination quicker… time is money. Besides, as long as you’re not going under the minimum speed limit (if the Autobahn has one), one is perfectly free to drive slower, if one wishes to get better fuel economy or to save the planet.

By: Evan

Evan — Fri, 08 Apr 2011 17:09:03 +0000

The only thing did 55mph speed limit was allow police to ticket drivers more. No one slowed down.

By: Pablo

Pablo — Thu, 07 Apr 2011 21:48:28 +0000

http://www.grc.nasa.gov/WWW/K-12/airplane/momntm.html

The velocity used in the aerodynamic equation is the relative velocity between an object and the flow. The aerodynamic force depends on the square of the velocity. Doubling the velocity quadruples the force. The dependence of lift and drag on the square of the velocity has been known for more than a hundred years. The Wright brothers used this information in the design of their first aircraft.

http://en.wikipedia.org/wiki/Drag_coefficient
The cross-section of the car “A” is also important.
The density of the air is also important, so the speed limit in the mountain states could be higher.

When optimizing the speed limit we need to put weight factors on the time spent for traveling and on the traffic accident statistics.

I would say 75mph is good limit for Prius.
The pick-up trucks and the SUVs have terrible shape and they need lover speed limit.

By: Dave S

Dave S — Thu, 07 Apr 2011 15:46:17 +0000

this is incorrect… Reducing the vehicles speed from let’s say 70 to 55 DOES improve fuel mileage. It doesn’t matter what you drive.

By: Dom

Dom — Thu, 07 Apr 2011 14:12:46 +0000

Oh good grief. They already tax the wazoo out of fuel in Europe… I don’t think the Autobahn is killing the planet considering Europe has a great selection of really fuel-efficient cars.

By: Henry Stowe

Henry Stowe — Thu, 07 Apr 2011 12:09:34 +0000

This is the most idiotic idea proposed yet. I am sympathetic to the idea of saving energy, but posting lower speed limits did NOT improve the fleet fuel mileage in 1974-76. According to Energy Information Agency figures, fleet fuel mileage in 1973 was 11.9 mpg. In 1974 it was 12.0 mpg, which was still below the 1968-72 levels. Fleet gas mileage did not start going up until the new CAFE requirements took effect in 1976-1980.

To save energy people need to ditch their cars for one day a week, combine trips, cancel their road trips, and junk their gas guzzlers (if they can afford to do so). This will have way more of an effect than posting slow speed limits on freeways.