Texas says: "Step on the gas pedal"

[Nekota]

Driving a LEAF in Texas fast lane is going to be hard with speed limits going to 85 and typically drivers go over speed limit by 10 so 95 mph in the fast lane! As car safety has greatly improved over the years, this will increase the energy available in collisions and increase fuel consumption. Increasing by 10 mph over 55 results in 40% (65) 86% (75) and 139% (85) more kinetic energy in percent increase for the mph in (mph). I'm convinced that slowing down has many benefits but as usual I'm in the wrong again group. I gave a talk about owning and driving a LEAF at my workplace for Earth Day events and my closing point was :: "Being green is not about buying a special vehicle but about changing your energy consumption habits. Slowing down saves energy and is being green -- and you may get to live longer as well."


http://blog.gasbuddy.com/posts/Texas-says-Step-on-the-gas-pedal/1715-493150-971.aspx" onclick="window.open(this.href);return false;

 

[EdmondLeaf]

If you travel on IH35 north of Dallas be careful, Denton and other small towns have speed limit 60 mph and lot of cops waiting for you.

Exactly being green is about saving energy and you can do this by many ways.

 

[EricBayArea]

Sounds like a good talk you gave for Earth Day.

80mph is quite a pace. We have a long stretch of highway in California that connects Northern California to Southern California along Highway 5 (which runs all the way from Mexico up to Canada). This particular stretch is in the center of California and is a 230 mile stretch of vast nothingness. 2 lanes each direction separated by a large median. The speed is 75mph but people are constantly going faster.

In normal commuting and driving to events/friends/etc. I typically drive green, as you have described it. However, when I drive to Southern California along this long stretch, I really want it to be over as soon as possible. I completely see the impact of going 75mph over 65mph in fuel economy. However, I would support a move to raise the speed limit on this stretch of highway.

However, I don't support high speeds on highways that are going through populated areas, have many/complicated on/off ramps, highway merges, or basically anything other than bland flat-road driving.

 

[DaveEV]

We have a long stretch of highway in California that connects Northern California to Southern California along Highway 5 (which runs all the way from Mexico up to Canada). This particular stretch is in the center of California and is a 230 mile stretch of vast nothingness. 2 lanes each direction separated by a large median. The speed is 75mph but people are constantly going faster.

Speed limit on I5 is 70 mph, not 75. Speeds up to 80 mph are tolerated by the CHP.

They impound a good number of cars who excessively speed faster than that.

I really dislike that stretch of road. Too many impatient drivers tailgating way too close at speeds that are too high when you inevitably have to pass slower truck traffic (who have a posted maximum speed of 55 mph though most do ~65 mph.

I've seen many bad accidents and haven't even driven the route that often. STAY AWAY if there is fog. There's been 100 car fatal pileups due to people driving too fast for conditions.

 

[adric22]

Driving a LEAF in Texas fast lane is going to be hard with speed limits going to 85 and typically drivers go over speed limit by 10 so 95 mph in the fast lane!

I wouldn't expect to see those higher speed limits in town anywhere, or much of anywhere that you'd expect to be driving with a Leaf.

While I do tend to drive at or above the speed limit myself, one thing that irritates me about some folks is how they will get really ticked off if somebody drives below the speed limit. After all, the term "speed limit" means by definition that you can drive at any speed UP TO that limit. It doesn't require you to drive that speed, unless there is a sign with a minimum speed limit posted.

I was in Germany a few years ago and I liked how they had different speed limits for different lanes of the highway.

 

[Pipcecil]

Working in transportation those 85 mph will be very rare (think IH 10 in west texas were there is absolutely nothing). Some places are increasing to 75, most notibly sections of IH 35 south of temple to Austin, IH 10 going to Houston from San Antonio, IH 45 between Houston and Dallas...basically all your travel in more small/rural towns long the interstate. In the cities the speed limits won't change. Most are still 60 or 65.

As for people always going 10 mph over the speed limit is a myth. When done correctly (I must add that in there because many roads don't) on all TxDOT owned and toll roads in texas us a 85 percentile speed which is redone every 5 years (txdot is notorious for not doing it every 5). They set the speed limit on any road by doing a week long survey and setting limit that at least 85% of the vehicles are traveling or slower. This is then modified by the desgin speed of the roady (can't exceed), top speed limit in the state (can't exceed), and any environmental speed limits imposed on that section of the roadway (can't exceed).

Once a speed limit is set, the reality speed is quite a shocker. Helping with some traffic studies and test in my day, only 25% of all vehicles actually travel the speed limit on any given section of a roadway. 25% base their speed off the speed limit but modified (i.e. travel 10 miles faster or 5 miles faster or 5 miles slower, etc.) The majority, 50%, travel at speeds at "whatever they feel most comfortable" and ignore any speed limits. Thats a really large chunk of traffic, which is why nailing the 85 percentile is so important to make sure the 25% that obeys the speed limit meshes with the 50% going at whatever speed they feel.

 

[Nubo]

...
In normal commuting and driving to events/friends/etc. I typically drive green, as you have described it. However, when I drive to Southern California along this long stretch, I really want it to be over as soon as possible. ...

Having driven that stretch a number of times I can sympathize with that desire. But the math doesn't really bear out. At the speed limit of 70mph, 230 miles takes 3:17. At 75mph, that distance still takes 3:04. That 13 minute savings isn't much. You've also increased fuel consumption meaning a fuel stop sooner than otherwise. Also increases workload dramatically as one has to constantly pass trucks and then get back in the right lane to let the even faster people by. Very hectic and the drivers are among the worst tailgaters I've ever experienced. The miserable behavior is a primary reason why that drive sucks. So I take it out of the equation.

When I travel that route I set my speed at 69 This puts me in the right lane only slightly faster than truck traffic so passes are far between. When it's coming time to pass a truck I get up to whatever the prevailing speed seems to be, make the pass and get back into "calm water". The reduction in tension is well worth far more than a few extra minutes.

 

[camasleaf]

...get back into "calm water". The reduction in tension is well worth far more than a few extra minutes.

Yes, I noticed that too: driving just slightly bellow speed of the trafic makes the trafic seem a lot lighter . Totally worth the extra minutes.

 

[Drivesolo]

Speed limit is going up to 85 mph in parts of Texas? Nice. Seems like the popularity of the Texas Mile is making an impact on the state.

 

[TomT]

A popular method to game that system in California is to do heavy radar and motor-cop speed enforcement during the week that they are doing the survey. That then ultimately results in an artificially low speed limit.

They set the speed limit on any road by doing a week long survey and setting limit that at least 85% of the vehicles are traveling or slower.

 

[gasmiser1]

Probably a good time to reexamine bringing back speed limit max of 55 mph to save fuel. People are in too much of a rush and aren't that great drivers at high speeds.

 

[derkraut]

Probably a good time to reexamine bringing back speed limit max of 55 mph to save fuel. People are in too much of a rush and aren't that great drivers at high speeds.

Amen to the above! :idea:

 

[TomT]

No thank you. That policy was a disaster on many fronts. Plus, many states found an easy way to circumvent it anyway.

Probably a good time to reexamine bringing back speed limit max of 55 mph to save fuel. People are in too much of a rush and aren't that great drivers at high speeds.

 

[Bassman]

Nobody does 75 mph on that stretch of I-5 from Patterson to the base of the grapevine. If you do, you'll get run over or seriously tailgated. 80 mph barely keeps up with the flow.

 

[dgpcolorado]

Driving a LEAF in Texas fast lane is going to be hard with speed limits going to 85 and typically drivers go over speed limit by 10 so 95 mph in the fast lane! As car safety has greatly improved over the years, this will increase the energy available in collisions and increase fuel consumption. Increasing by 10 mph over 55 results in 40% (65) 86% (75) and 139% (85) more kinetic energy in percent increase for the mph in (mph). I'm convinced that slowing down has many benefits but as usual I'm in the wrong again group. I gave a talk about owning and driving a LEAF at my workplace for Earth Day events and my closing point was :: "Being green is not about buying a special vehicle but about changing your energy consumption habits. Slowing down saves energy and is being green -- and you may get to live longer as well."


http://blog.gasbuddy.com/posts/Texas-says-Step-on-the-gas-pedal/1715-493150-971.aspx" onclick="window.open(this.href);return false;

I've long been cognizant of the kinetic energy impact of high speeds and am none too comfortable at 70-75 mph. But 85 is just ridiculous. My theory: Since Texas is a famous oil-producing state and headquarters for numerous oil companies, the 85 mph speed limit policy is intended to encourage increased oil use.

Freeway speed limits in Colorado, Utah, and Idaho are all 75 and it isn't until I get to Oregon that they drop down to 65. I just set the cruise to 65-67 for gas mileage reasons, stick to the right lane, and enjoy my audiobooks. But traffic is so light that impeding traffic isn't a concern in the Great Basin area.

 

[GoingGreener]

REDUCING the speed limit from 65mph to 55mph is being considered for the SF Bay Area. Seems worthwhile to slow down for better air quality. Here's an article from the SF Examiner last week:

http://www.sfexaminer.com/local/transportation/2012/04/55-mph-limit-pitched-pollution-fighter?utm_source=feedburner+sfexaminer%2FLocal&utm_medium=feed+Local+News&utm_campaign=Feed%3A+sfexaminer%2FLocal+%28Local+News%29feed&utm_content=feed&utm_term=feed" onclick="window.open(this.href);return false;


"...Dropping the maximum limit by 10 mph could reduce emissions 6 percent by 2035 — the equivalent of taking 300,000 cars off the road, said Amir Fanai of the Bay Area Air Quality Management District.

Research shows vehicles are most environmentally efficient when they travel between 40 and 55 mph, Fanai said. Accelerating by just 10 mph — from 55 to 65 — can double emissions, he said... "

 

[Nubo]

Nobody does 75 mph on that stretch of I-5 from Patterson to the base of the grapevine. If you do, you'll get run over or seriously tailgated. 80 mph barely keeps up with the flow.

No, not really. See my previous post. The fast drivers leave you alone as long as you're in the right lane. They prefer to thunder along in the left lane anyway due to truck traffic. The only caveat is that when I do venture left to pass a slow truck, it's best if I just giddyup to whatever speed is dominant in that lane and get the pass over with quickly. The end result is a very much reduced workload. The people who are obsessed with traveling 80 and above, are CONSTANTLY having to adjust speed, brake, change lanes, accelerate... and then they tailgate which keeps them even busier -- but they are mostly tailgating other left-lane drivers.

 

[DaveEV]

Having driven that stretch a number of times I can sympathize with that desire. But the math doesn't really bear out. At the speed limit of 70mph, 230 miles takes 3:17. At 75mph, that distance still takes 3:04. That 13 minute savings isn't much. You've also increased fuel consumption meaning a fuel stop sooner than otherwise.

Yep. Even if you could average 85 mph still takes 2:42. (Never mind that an 85 mph average is impossible unless you actually drive 90mph+ to make up for having to slow down for traffic).

Also increases workload dramatically as one has to constantly pass trucks and then get back in the right lane to let the even faster people by. Very hectic and the drivers are among the worst tailgaters I've ever experienced. The miserable behavior is a primary reason why that drive sucks. So I take it out of the equation.

When I travel that route I set my speed at 69 This puts me in the right lane only slightly faster than truck traffic so passes are far between. When it's coming time to pass a truck I get up to whatever the prevailing speed seems to be, make the pass and get back into "calm water". The reduction in tension is well worth far more than a few extra minutes.

Yep, exactly. Whenever I drive that route I typically stick to low 70s and avoid the crazy people hell-bent on going as fast as possible and tailgating at 1-2 car lengths at 80 mph. Much less stressful.

Nobody does 75 mph on that stretch of I-5 from Patterson to the base of the grapevine. If you do, you'll get run over or seriously tailgated. 80 mph barely keeps up with the flow.

I've never had a problem with 70 mph as long as you keep right to let faster traffic through.

 

[Pipcecil]

REDUCING the speed limit from 65mph to 55mph is being considered for the SF Bay Area. Seems worthwhile to slow down for better air quality. Here's an article from the SF Examiner last week:

http://www.sfexaminer.com/local/transportation/2012/04/55-mph-limit-pitched-pollution-fighter?utm_source=feedburner+sfexaminer%2FLocal&utm_medium=feed+Local+News&utm_campaign=Feed%3A+sfexaminer%2FLocal+%28Local+News%29feed&utm_content=feed&utm_term=feed" onclick="window.open(this.href);return false;


"...Dropping the maximum limit by 10 mph could reduce emissions 6 percent by 2035 — the equivalent of taking 300,000 cars off the road, said Amir Fanai of the Bay Area Air Quality Management District.

Research shows vehicles are most environmentally efficient when they travel between 40 and 55 mph, Fanai said. Accelerating by just 10 mph — from 55 to 65 — can double emissions, he said... "

Texas starting in 2002 or 2003 (can't remember exactly) did a whole environmental speed limit to 55 mph to reduce emissions for air quality attainment. It failed miserably with no results but causing more traffic congestion so it was removed. Despite the removal some roads still cling to an environmental speed limit (usually 60) here in Texas.

For air traffic pollution caused from cars, the main culprit is carbon monoxide. CO is easily modeled too and is a direct result of acceleration of a vehicle. So, moving traffic creates little to no polution while braking/accelerating constantly (congestion) as well as stopping and accelerating again is the bulk of all emissions a standard ICE vehicle produces. So even with increased average daily traffic (ADT) as long as the traffic moves its contributing little to pollution as a smaller ADT on a roadway but stuck in congestion. This is why stop signs, signals, and toll booths are directly modeled as they cause more poullution at those sources than a free moving area (even if significantly faster). The problem with the 55 mph speed or ANY speed that is set too low (from a failed or inaccurate speed test) results in more cars going faster than the speed limit and having to break and accelerate constantly, thereby causing more pollution. You could argue that if everyone obeyed the speed limit this wouldn't happen, but even cop presents is only a temp fix, you would need a constant cop monitoring and/or speed cameras to solve the issue permanently, or, the cheaper solution, just raise the limit to what most traffic goes. Now this is only for the air quality portion, speed & accidents I don't have any info on.

 

[ksnogas2112]

The old double nickel would definitely be good to see back in suburban/urban areas. As much as I am for saving gas/oil etc, driving west across Kansas makes me want a 90mph speed limit.