75 mph up north, the world didn't end (design, car)

[Craziaskowboi]

Originally Posted by beltrams

I've also noticed, having driven the 75mph section quite a bit now (too much actually), that it is indeed true people don't automatically go 10 mph over any speed limit. That is, I don't see people going over the 75 limit nearly as much as people go over the 55 and 65 limits in those other areas. So, all those that predicted carnage can relax.

I've been saying this since I got my driver's license, and finally there's some proof. People have their own preferred speeds for Interstate driving, and they're not going to exceed those speeds just for the sake of driving 10 miles per hour over the speed limit.

Let's assume that there's a certain person who would drive 75 miles per hour on the Interstate if left to his own devices. When the speed limit was 55, he desired to drive much faster, but he also didn't want to attract the attention of the highway patrol, so he compromised and drove 65. Then, when the speed limit was raised to 65, he increased his speed to 75, which was the speed that he wanted to drive all along. Even though he was still 10 over the speed limit, at least he could drive his preferred speed without the cops on his ass. Unfortunately, the fact that he sped up led others to believe, falsely, that he just wanted to push the envelope regardless of the speed. When the speed limit was increased to 75, however, a funny thing happened: he didn't suddenly start driving 85, because 75 is the rate he felt most comfortable driving in the first place. He felt no need to speed up anymore.

Plain and simple, the speed that people feel most comfortable driving varies. It could be as low as 60 or as high as 90, but 99% of all drivers on the Interstates prefer to drive within that range. My personal zone is somewhere between 85 and 90. Interstate driving feels cumbersome under 85 miles per hour, but reckless over 90 miles per hour, so I keep it steady, typically around 87 or 88. The speedometer needle tickles the top of the '9,' but never reaches 90. If the speed limit where I am was raised to 75, then I'd drive 85, but if it was raised to 80 then I'd barely speed up, and if it was raised to 85, then I'd be within the margin of speedometer error. I wouldn't feel the need to drive 95, because I don't want to drive faster than 85 to 90.

If you prefer to drive slower than me, or even below the speed limit, then that's fine; just keep right except to pass. Even at higher speeds, I move back into the right lane myself when there's nobody to pass, because there could be somebody behind me who wants to drive faster than 90. I wouldn't drive as fast as that person, but I'd allow him by nonetheless. If you prefer to drive under 60 miles per hour, though, then do us all a favor and stick to the secondary roads. The Interstates are meant for speeds faster than that which you want to drive, and the less bogged down they are with slow cars, the more efficiently the entire system works. Everybody wins this way: the faster drivers and I can drive at our preferred speeds with minimal interference, and you and the slower drivers can relax and not worry about us "crazy" fast drivers.

The fact that people kept driving 10 miles per hour over the speed limit when it was raised twice doesn't mean that they would continue to drive 10 over if it was increased 10 times. It just means that the speed limits were set so low that you had to increase them by 20 to 25 miles per hour in order for most people to be at or below them while driving at their preferred speeds.

[Coaster]

Originally Posted by ram2

Incorrect. People could not buy gas - therefore they could not drive. Even the Daytona 500 was only run for 450 miles in 1974.

Look, it's obvious you don't want to accept the reality of what was happening in that era and the incontrovertible evidence that dropping the speed limit saved lives, so arguing with you about it is hopeless. The numbers are there. If you choose not to accept them because they don't agree with your fantasy, I suppose there's not much I can do about it.

[beltrams]

Actually, there was a drop in vehicle miles traveled both after the first oil shock and then after the 1979 one. As a matter of fact, vehicle miles traveled has dropped a bit again since 2006:




That graph is adjusted for population growth, so it's easier to see the short term dips in 1974-5, 79-81, and 2006ish to now.

Now here is a raw mileage traveled graph, unadjusted for population growth:



The miles traveled drops in 1974 and 79 are still there, but harder to see. Notice also the truly historic downturn just in the past few years. Recently the Maine Turnpike Authority said that they have to raise toll rates because lower traffic counts have impacted their budget and looking at that last graph, I can see why.

Edited to add one more graph I just found of raw total mileage data since 1971, which makes the oil shock-induced traffic drops easier to see:

[Zymer]

If you prefer to drive under 60 miles per hour, though, then do us all a favor and stick to the secondary roads. The Interstates are meant for speeds faster than that which you want to drive, and the less bogged down they are with slow cars, the more efficiently the entire system works. Everybody wins this way: the faster drivers and I can drive at our preferred speeds with minimal interference, and you and the slower drivers can relax and not worry about us "crazy" fast drivers.

Just because the maximum speed limit is a certain number doesn't mean that *everyone* is required to drive at or near that speed. The minimum speed limit on an Interstate highway is 45, you must maintain at least that speed and vehicles not capable of that speed are banned from using the Interstate. A vehicle being driven at 45mph is being operated within the legal parameters, if you don't like it...too bad, deal with it. Not everyone is comfortable driving at higher speeds.

[todd00]

Personally, I see no need for going nearly 90 mph, unless of course there is some emergency. How much time are you really saving, not much. Most people aren't trained at high speed driving or even realize how little time they have to react or stop if danger quickly presents itself. If you want to race go to track, its safer for everyone.

[ram2]

[quote=Gnutella;24801368]I've been saying this since I got my driver's license, and finally there's some proof. People have their own preferred speeds for Interstate driving, and they're not going to exceed those speeds just for the sake of driving 10 miles per hour over the speed limit.

quote]


When posted speed limits are based on measured 85th percentile vehicle speeds, you will have what you describe above.

[mensaguy]

Originally Posted by Zymer

Just because the maximum speed limit is a certain number doesn't mean that *everyone* is required to drive at or near that speed. The minimum speed limit on an Interstate highway is 45, you must maintain at least that speed and vehicles not capable of that speed are banned from using the Interstate. A vehicle being driven at 45mph is being operated within the legal parameters, if you don't like it...too bad, deal with it. Not everyone is comfortable driving at higher speeds.

Absolutely right! If you don't like the minimum speed limit, go lobby your legislator to have the rule changed. Just like anything else (law, regulation or Constitutional provision), if you don't like it, there is a process to make it change.

[mensaguy]

Originally Posted by ram2

When posted speed limits are based on measured 85th percentile vehicle speeds, you will have what you describe above.

I don't expect to see speed limits set higher than the speeds for which the highways were designed, no matter what the so-called measured 85th percentile might indicate.

[Coaster]

Originally Posted by beltrams

Actually, there was a drop in vehicle miles traveled both after the first oil shock and then after the 1979 one. As a matter of fact, vehicle miles traveled has dropped a bit again since 2006:




That graph is adjusted for population growth, so it's easier to see the short term dips in 1974-5, 79-81, and 2006ish to now.

Now here is a raw mileage traveled graph, unadjusted for population growth:



The miles traveled drops in 1974 and 79 are still there, but harder to see. Notice also the truly historic downturn just in the past few years. Recently the Maine Turnpike Authority said that they have to raise toll rates because lower traffic counts have impacted their budget and looking at that last graph, I can see why.

Edited to add one more graph I just found of raw total mileage data since 1971, which makes the oil shock-induced traffic drops easier to see:

I used the information in the chart at: List of motor vehicle deaths in U.S. by year - Wikipedia, the free encyclopedia in particular the deaths per 100 million miles to show the effect of the drop in the speed limit between 1973 and 1975.

Regarding the most recent drop in miles driven, there's a chart at Mish Shedlock's site showing that the last 14 years of growth in petroleum use in the United States has been wiped out, while gasoline consumption has dropped to levels not seen since 2002. The chart can be found at: Mish's Global Economic Trend Analysis: 3-Month Petroleum Usage Chart for March, April, May Shows 14 Years of Supply Demand Growth has Vanished

I know here in Maine traffic on the Maine Turnpike is down, as you note, and I've been looking for stats on gasoline usage in Maine. The Maine DOT used to release figures on total miles driven per year, but those numbers seem to be eluding me at the moment. I would bet they reflect the national trends, perhaps even more sharply. Given what I'm seeing personally and hearing from others, heating oil use is down in Maine as well.

Maybe the new 75 mph speed limit is actually a ploy by the oil companies to increase gasoline consumption!

[Submariner]

Originally Posted by Zymer

Just because the maximum speed limit is a certain number doesn't mean that *everyone* is required to drive at or near that speed. The minimum speed limit on an Interstate highway is 45, you must maintain at least that speed and vehicles not capable of that speed are banned from using the Interstate. A vehicle being driven at 45mph is being operated within the legal parameters, if you don't like it...too bad, deal with it. Not everyone is comfortable driving at higher speeds.

On occasion I see vehicles from the 60s tooling along doing 45 - 50 mph. Often they are driven by white-haired drivers. I assume that it was their first vehicle and they have managed to keep that one vehicle going all these years.

I do not see the minimum speed being a problem, or any need to change it.

I have a Willy that can not get up that fast, so I do not take it on the interstate.

My pickup sometimes has difficulty holding 50mph on the hills, but that only happens when loaded with a tonne of manure and towing my trailer hauling a tractor. I only did that a few times. Once I realized that it does not have the wheaties to climb those hills, I have changed to only using secondary roads when I am hauling manure.