NA Highway speed limits NA

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
Joined
Feb 23, 2005
Messages
20,940
Location
west Texas
Display Name
Display name:
Dave Taylor
So, what exactly are the new speed limits? Seems like they have changed but for which vehicles, where, and what are the new limits? Does it matter if none of the signs have changed?
 
?????

My 5 yr old Big Truck likes to cruise about 10mph above whatever is posted, but that is by no means it's limit. :wink2:
 
I am reading it changed, it didn't change, as of today. Depends on source.
I guess I will stick to my policy of ''safest is keeping them in my rear view mirror and no chance of catching me'!
 
The national speed limit of 55 mph has been repealed.

Like 30 years ago.
 
If a trip is long enough to make the speed limit an issue, I fly.

Texas is just too damned big to drive around.
 
KS just bumped up to 75, but only once you get out into the rural areas, which doesn't take much. Until you get there, it could be anywhere from 70 to 65 to 55. I didn't notice any signs limiting trucks to a different speed limit.
 
About 5 years ago driving through west Texas, I was surprised to see 80 mph speed limit signs on I-80. Did they change?

I really, really hate speed limits. "Safe and prudent" should be the law. What that is varies heavily dependent on the conditions and what you're driving. I've had days when going half the speed limit was unsafe, and other days when going twice the limit was safe.

The yellow signs should exist to give recommended speeds for the average vehicle as we currently have set as limits. Those with better vehicles and better skills can drive faster. Those who can't, drive slower. You wreck because you were going too fast? Expect to get nailed for reckless driving.
 
Ted DuPuis said:
About 5 years ago driving through west Texas, I was surprised to see 80 mph speed limit signs on I-80. Did they change?
Click to expand...

Dude, I'd be surprised to see an I-80 sign in TX, unlessin I'd been eatin some of them mushrooms that turn blue when you scratch them...;)
 
Matthew said:
KS just bumped up to 75, but only once you get out into the rural areas, which doesn't take much. Until you get there, it could be anywhere from 70 to 65 to 55. I didn't notice any signs limiting trucks to a different speed limit.
Click to expand...
Was that pretty recent? The last time I drove on I-70 in KS it was still 70. That was in May. I always think it's funny that CO is 75 and KS is 70. CO actually goes to 75 on the interstates just as you reach the outskirts of metro areas.
 
I like the way the Germans handle speed limits. They have electronic signs, linked to traffic density sensors.

Traffic heavy? The speed limit goes down. Traffic light? The speed limit goes up.

This makes way too much sense to ever work here...
 
PHP:
Henning said:
Dude, I'd be surprised to see an I-80 sign in TX, unlessin I'd been eatin some of them mushrooms that turn blue when you scratch them...;)
Click to expand...

Your observation is correct. I-10 it was. :)
 
Everskyward said:
Was that pretty recent? The last time I drove on I-70 in KS it was still 70. That was in May. I always think it's funny that CO is 75 and KS is 70. CO actually goes to 75 on the interstates just as you reach the outskirts of metro areas.
Click to expand...

Yeah - it was just within the last couple of months. We drove down I-35 from Olathe to Emporia in August. It's 75 now, once you get out of town.

There used to be a disconnect at the KS/CO border because the speed limits were different. There were always State Troopers waiting right there to catch you as soon as you crossed the border.
 
Talked to a trooper today, only local change is no more special night time limits, and truckers can drive same speed as everyone else.
 
Jay Honeck said:
I like the way the Germans handle speed limits. They have electronic signs, linked to traffic density sensors.

Traffic heavy? The speed limit goes down. Traffic light? The speed limit goes up.

This makes way too much sense to ever work here...
Click to expand...

Never driven I-4 through Orlando, I take it. They've got exactly what you describe.
 
Let'sgoflying! said:
I am reading it changed, it didn't change, as of today. Depends on source.
I guess I will stick to my policy of ''safest is keeping them in my rear view mirror and no chance of catching me'!
Click to expand...

In Texas the different night time speed limits went away (the black signs, white numbers). The posted daytime speed limits are good 24hrs a day now (white signs, black numbers). We were one of (I think the only) state that different speeds for different times of day until Sept 1.
 
We've got bits of 80MPH freeways here in Utah. Been that way for a few years.
Of course, we NEED that to speedily get through the vast nothingness that is central Utah.
:D
 
we used to have "Reasonable & Prudent" in MT.

resonableprudent.jpg
 
KSCessnaDriver said:
Never driven I-4 through Orlando, I take it. They've got exactly what you describe.
Click to expand...

So when there's no traffic on the I-4, you can go as fast as you want? And drivers keep right, except to pass, ALWAYS? :rolleyes:

It's pretty effortless to drive 100mph in my car and it can cruise at about 150 at which point, the water and oil temperatures start noticeably coming off their "normal" marks. Top speed is gear limited somewhere around 170mph I'd say.

If I could drive that fast, legally, I'd have less reason to buzz around in a Cessna 152...
 

Attachments

  • 139mph.jpg
    139mph.jpg
    48.8 KB · Views: 28
KSCessnaDriver said:
Never driven I-4 through Orlando, I take it. They've got exactly what you describe.
Click to expand...

The difference is that Germany also has these signs:

nospeedlimit.jpg


Which mean "No Speed Limit." There are a lot of areas where that should be the case, and it's not. I-4 around Orlando is not one of those places, but in Germany it wouldn't be, either.

MSPAviator said:
It's pretty effortless to drive 100mph in my car and it can cruise at about 150 at which point, the water and oil temperatures start noticeably coming off their "normal" marks. Top speed is gear limited somewhere around 170mph I'd say.
Click to expand...

Although I don't have pictures purgering myself like that in the Mitsubishi, I do have the following on the Autobahn:

220kmh.jpg


Of course, note that's in Kilometers in an Alfa Romeo 156 with the V6. Oh, what a sweet, sweet engine. ;)

My 3000GT VR-4 could do similar to your car quite happily, probably hit about 200, and I doubt it would overheat with the cooling upgrades I've made, and the turbos wouldn't even be working too hard with the intercooler. But...

If I could drive that fast, legally, I'd have less reason to buzz around in a Cessna 152...
Click to expand...

Sure you would. Your car at those speeds will be running at a significantly richer air/fuel ratio. My Aztec gets about 9 MPG @ 180 mph running LOP. My Mitsubishi would probably get about 5 MPG @ 180 mph, and have to stop for fuel much, much more frequently. Now, at the speed of a 152, correct, you'd have no reason to fly that instead of driving your car. However, something like a Bonanza is going to be hard to beat, even the Aztec, as much of a pig as it is. Good luck getting 14-15 mpg at 200 mph with any ground-based vehicle.

This is one of those bits about car engines not being optimized for continuous high-power operation. The Cadillac Northstar, for instance (and many others) have programming in them to run pretty lean at high power for about 10 seconds. This is to meet the emissions requirements. After those 10 seconds, however, the plugs are about ready to melt and it goes to an incredible 10 or 11:1 AFR (very rich) to keep things happy.
 
Ted DuPuis said:
This is one of those bits about car engines not being optimized for continuous high-power operation. The Cadillac Northstar, for instance (and many others) have programming in them to run pretty lean at high power for about 10 seconds. This is to meet the emissions requirements. After those 10 seconds, however, the plugs are about ready to melt and it goes to an incredible 10 or 11:1 AFR (very rich) to keep things happy.
Click to expand...

Yeah, I dunno about that. I've run my car basically at full throttle for 20 minutes at a time, 90 minutes a day, for two days, yielding about 180mi. on a 21.5 gallon tank of fuel on a couple race tracks around the country, then turn around and drive me home, a several hours or halfway across the country away. (Brainerd International Raceway, Road America, Mid-America Motorsports Park, Summit Point)

I have seen new Cadillac CTS-V's try to do the same thing and overheat because they're just not designed to be driven the same way as German cars are... and the Caddy was basically brand new, my car will be turning 17 years old in about three months. :D
 

Attachments

  • Cadillac.jpg
    Cadillac.jpg
    40.9 KB · Views: 26
MSPAviator said:
Yeah, I dunno about that. I've run my car basically at full throttle for 20 minutes at a time, 90 minutes a day, for two days, yielding about 180mi. on a 21.5 gallon tank of fuel on a couple race tracks around the country, then turn around and drive me home, a several hours or halfway across the country away. (Brainerd International Raceway, Road America, Mid-America Motorsports Park, Summit Point)
Click to expand...

Well, that 180 mi and 21.5 gallons gives you 8.4 mpg, so still worse than my Aztec, while going slower. That was my point. :)

I have seen new Cadillac CTS-V's try to do the same thing and overheat because they're just not designed to be driven the same way as German cars are... and the Caddy was basically brand new, my car will be turning 17 years old in about three months. :D
Click to expand...

The CTS-V isn't, that's correct. However I've seen German cars overheat, blow head gaskets, etc., and my Dodge has run at about full throttle up a hill in 100+F degree temps with a trailer for an extended period of time, and didn't overheat. So it's not American vs. German, it's just the specifics of each. :)
 
I've operated multiple terrestrially limited vehicles, some of the best of them, and anything that is going over 150mph is like operating a jet up in the coffin corner. You have a very limited envelope of what you can do before you lose control. I have lost control at speeds in excess of 150 mph a few times in my life and I can tell you this, you will not regain control, and if you're on a motorcycle, it's likely gonna hurt. 220mph in even the best of best cars is not an experience to be taken lightly. You are on the very edge of being able to control your inertia. Any upset will likely be catastrophic.

Aircraft raise the speed stakes by an order of magnitude. 150 is easy to control in an airplane, heck it's barely into the bottom of "performance", you can even "fail" and recover sometimes.
 
Last edited:
MSPAviator said:
Yeah, I dunno about that. I've run my car basically at full throttle for 20 minutes at a time, 90 minutes a day, for two days, yielding about 180mi. on a 21.5 gallon tank of fuel on a couple race tracks around the country, then turn around and drive me home, a several hours or halfway across the country away. (Brainerd International Raceway, Road America, Mid-America Motorsports Park, Summit Point)

I have seen new Cadillac CTS-V's try to do the same thing and overheat because they're just not designed to be driven the same way as German cars are... and the Caddy was basically brand new, my car will be turning 17 years old in about three months. :D
Click to expand...


I can sell you a machine faster and way more fun than your German motorcar....;) Traveling low is nice when you have two engines, there are some great views to be had and with 2 engines and a bunch of excess energy, it wouldn't be any great shakes to lose an engine. I waved across at the truckers in Cajon pass before.:D
 
What dynamics are happening at these speeds; I am imagining the Cf drops, the airloads multiply, and the car might do some uncommanded yawing.
 
Let'sgoflying! said:
What dynamics are happening at these speeds; I am imagining the Cf drops, the airloads multiply, and the car might do some uncommanded yawing.
Click to expand...


Multiple factors, but mostly just your inertia is the problem. The key issue is that with a land controlled vehicle your entire control basis is governed by the coefficient of friction of you wheels. Every control change you make requires an accelerational force to overcome your inertia to correct your vector. If you apply to much correctional force you overcome the coefficient of friction of your surface contact so you lose control of your vector as gyroscopic forces in your wheel start to overpower your arms and then with sudden different accelerational vectors happening at once start to oscillate into a shake and things get ugly really fast from there as you just pull yourself into the tightest package you can and go for an E-ticket ride.

With airplanes you the entire surface of the aircraft to use to maintain inertial stability, gives a huge advantage.
 
Henning said:
I've operated multiple terrestrially limited vehicles, some of the best of them, and anything that is going over 150mph is like operating a jet up in the coffin corner. You have a very limited envelope of what you can do before you lose control. I have lost control at speeds in excess of 150 mph a few times in my life and I can tell you this, you will not regain control, and if you're on a motorcycle, it's likely gonna hurt. 220mph in even the best of best cars is not an experience to be taken lightly. You are on the very edge of being able to control your inertia. Any upset will likely be catastrophic.

Aircraft raise the speed stakes by an order of magnitude. 150 is easy to control in an airplane, heck it's barely into the bottom of "performance", you can even "fail" and recover sometimes.
Click to expand...

You referring to Ted's speedo/tach picture? 220 km/h = 136.7 mph. Your 150+ experience has his example beat. A few people might think you are both nuts. :rolleyes:
 
Gmaper said:
You referring to Ted's speedo/tach picture? 220 km/h = 136.7 mph. Your 150+ experience has his example beat. A few people might think you are both nuts. :rolleyes:
Click to expand...


220kph is just starting to get "fast". You'd be amazed at how many cars in the days before computer limiters would do 140. I've made a couple tries at the "Thee Club" but wasn't successful. Next time if I try it I'll have a real budget.
 
Haha, I prefer flying to driving anyday, although the fastest TAS I have seen while acting as PIC is only about 140kt. :(

The biggest obstacle to being able to drive faster in the US is the low standard of driver training and the complete lack of lane discipline.
 
MSPAviator said:
I have seen new Cadillac CTS-V's try to do the same thing and overheat because they're just not designed to be driven the same way as German cars are... and the Caddy was basically brand new, my car will be turning 17 years old in about three months. :D
Click to expand...

I note you reference the Caddies in the plural - how many?
 
Gmaper said:
You referring to Ted's speedo/tach picture? 220 km/h = 136.7 mph. Your 150+ experience has his example beat. A few people might think you are both nuts. :rolleyes:
Click to expand...

I've had more than a few people call me nuts, but they're usually people who aren't worth paying attention to. ;)

The fastest I've gone in any road-based vehicle is 160 mph in my '82 XJ-S, and I'm sure Henning has beaten that by a significant margin. I really don't have any desire to go that fast in a ground-based vehicle anymore (that was back when my luck bucket was full). Even lacking speed limits 120 is probably about as fast as I'd go in my VR-4. 100-120 mph is very comfortable still in that car, as it was in my XJ-S (goes back to "safe and prudent"). North of that, things do happen exponentially faster, and you really won't be able to recover from a problem.
 
I went stupidly fast in a 1969 Chevrolet Caprice sedan, gold with a brown vinyl top and bias ply tires. Had a high-compression 350, smoothest-running car I ever owned.

It was up to something well over 120 (that's as high as the speedo went), not breathing hard - but the suspension was bottoming on most any highway irregularity, enough that it scared me. As it should have.

My Deville clearly had the juice to go fast, but it also had a cutoff at 113 MPH. Dull.
 
SCCutler said:
It was up to something well over 120 (that's as high as the speedo went), not breathing hard - but the suspension was bottoming on most any highway irregularity, enough that it scared me. As it should have.
Click to expand...

In the cars of those days, that's about right. My '69 Fleetwood did just fine about 85, but I wouldn't have wanted to push it faster (even though it could've done it).

My Deville clearly had the juice to go fast, but it also had a cutoff at 113 MPH. Dull.
Click to expand...

There are various programmers that you can buy to remove that limiter for most cars (I'd suspect your Deville included). The tires then become an issue (and are usually one of the reasons for the limiters).
 
Yep, Ted; the principal difference between the deville and the DTS, was the tires. The DTS had (IIRC) a 155 mph limiter.
 
Had my V6 Dodge Magnum up to 130+ at Mid Ohio before running outta track and having to turn. Smooth and still pulling with one of the smaller engines available. I have a feeling when I get my Saturn there I will hit the 144mph limiter.
 
I had the Fireblade faster than that by accident on a milk run. My brother's 86 Ninja beat and held 150 when I had to go out looking for my poor Alzheimer's-ridden father after he found a set of car keys I hadn't commandeered. Why they kept so many sets of keys I'll never know.

At that speed, the cars going by in the other lane turn to flashes of color. Had it not been the bright green Styrofoam ball on his aerial (a early adaptive response to the Alzheimer's) I wouldn't have known it was him. Want to know the one thing more dangerous that going 150 mph on a motorcycle? Slowing to a dead stop quickly. Henning is right. A get off would hurt good at those speeds.
 
You must log in or register to reply here.
Back
Top