Blinding, teeth clenching highway speeds and safety.

How fast is still “safe”? As you have probably experienced as well, when I have the opprotunity to drive at or over 100-mph, at first I feel as though I’ll lose control at the slightest provocation. In less than a minute I feel very comfortable with the speed (as long as I don’t have to deal with slower traffic). Inevitably, after I slow down to the posted highway speed, I feel as if this slower speed is much too sluggish. I’m left feeling as though speeds much higher than those currently posted on interstates could be raised greatly in the future as safely and economy issues are resolved.

My brother-in-law lives in Europe and has told me that when driving on the Autobahn, speeds far in excess of 100 mph feel perfectly comfortable. I’m sure that understanding traffic and the condition of the highway have a lot to do with his comfort level, but speed is speed, reaction time is reaction time and sphincter-tightening fear is sphincter-tightening fear.

If a car was designed and built to be driven at the highest possible speed and a road was designed and built to support vehicles traveling at that speed, how fast could a car be driven on this modern highway before the human body could not keep up with the mass of stimuli? Indy car drivers do it at very high speeds (no joke intended :D).

This is a serious question :rolleyes: that examines the potential for raw speed and adrenaline. Please do not turn this question into a morality play regarding the wasting of natural recourses and road safety ;).

Heck, humans safely operate aircraft at speeds far above any car, even F1. The vehicle itself is irrelevant; what matters more is:
[ul][li]Can you operate it safely without overcorrecting or undercorrecting?[/li][li]How well do you react to sudden obstacles?[/li][/ul]

On a perfectly straight smooth empty highway, I can’t see any problem with driving a conventional sedan as fast the engine will allow (a Toyota Camry, in my experience, has a speed governor that kicks in at 115mph). This is barely one-sixth as fast as the land speed record holder, though he was driving a rocket car across a desert.

Fact is, if high speed makes you nervous, you’re a hazard to yourself and everyone else on the road because if something unexpected does happen, you’re far more likely to screw up and you have less time to react. Slow down, bub.

One issue with driving at 100+ mph in the U.S. is the fear of being pulled over at this speed. This is generally considered to be reckless driving, and will likely result in one’s arrest. That’s one factor that may be increasing the adrenaline.

My experience with driving on the Autobahn in Germany was that you do generally get used to fairly quickly. I drove much more alertly, however, and generally had both hands on the wheel. Typical Autobahn speeds range from 100-120 mph, assuming no traffic (a BIG assumption). I have, however, driven as fast as 230 km/h (143 mph) in a Porsche 911. (I was also passed by a Mercedes E 500.)

What really increases the alertness level, however, is speed differentials. Vehicles (usually trucks) may legally travel as slowly as 60 km/h (37 mph). What helps is that there is absolutely no passing on the right, which is illegal and strictly enforced.

All in all, it was exhausting driving, though. I drove from Munich to Berlin several times, and found that I needed frequent breaks.

When slowing down to typical U.S. highway speeds, I also felt that I was barely moving. I’ve heard this term referred to as “velocitation.” Once, immediately upon returning to the U.S., I got onto the highway, and couldn’t figure why nobody seemed to be moving. One look at the speedometer showed that I was going 95 mph. :eek: (I slowed down, then.)

Just like slowing down to 35mph on a freeway exit ramp - you feel you could get out and walk. Driving 35 around town, however, feels like 35. The first few minutes of low speed after having driven at freeway speeds should always be taken carefully, with an eye on the speedometer.

Sometimes I get behind a person doing 55 in a 65 zone on the freeway and wonder if they are even awake. Feels like crawling.

Safe just depends on the driver,car, road design and conditions. On the highway, 75 feels perfectly safe to me( I’ve never driven over 80, I don’t like speeding tickets), while 55 feels retarded. Yet 55 would feel insanely fast driving on the road my house is on. Also some people have faster reaction times than others.

A separate point about safe speeds, is that other highway users have a “right” to expect other users to be travelling at sane speeds. Thus if I was overtaking someone, I would expect to need look in my mirror once before the manouver, and seeing a car far behind be sure they won’t interfere with the manouver. I check again just before changing lanes, if the distant vehicle was going anything up to 100 mph then everything will be fine and I’ll overtake succesfully with plenty of space to spare. If the distant vehicle was pushing 130 mph, I see they are now too close for my overtake, and I have to cancell my overtaking acceleration, reposition myself in the lane, and fall in behind the car I was going to overtake. Simply when cars go too fast you don’t get to observe them for long enough to accurately determine their speed, and this makes them dangerous.

The average person sucks at driving. So, the answer is that in the future, cars will be able to break harder. But i think at this point that we are at now is pretty close to the limit of safety, no doubt. Cars can only stop so quickly, because the limitations is in the tires, which will not get any softer.

The speed limit will not increase very much more, for sure. We are at the end, almost. Of course, there could always be stretches of road that are safe to drive in the day at 120mph. There is a stretch of road in my town that is safe to drive 150 in the right vehicle (Firebird for instance). No turn-offs, good pavement, good visibility, no cows around to break out of a fence.

I think that the speed limits should be raised only on interstates and on four lanes, not on two lane roads 55MPH is certainly fast enough on a two lane road. With the increase in vehicle safety and all around better performance such as handling, a big factor, cars are capable of faster speeds while maintaing the same safety standards.

I have a 2002 Corvette ZO6 (Red) and i find it nearly impossible to drive 55mph when on the highway. I normally cruise around 80mph until i realize that i could have my license revoked then i slow down to what seems like a snails pace.

55mph takes the fun out of driving.

I don’t think that the tires are currently the limiting factor in braking distances. In high-performance vehicles, yes, but in most cars, no. Think about it: a Civic has (IIRC) 2-piston disc brakes in front and drums in back…that is by no means the best possible brake setup.
Also, when driving on the freeway, you should not be braking at all, until you are on the off-ramp. Most people (who do suck at driving, you are dead on there) don’t realize that if you do some things, which may seem unnatural to some, you can avoid most freeway braking.[ul]
[li]Don’t do stuff other than drive. This means hang up the phone, don’t be eating, don’t be making out with your SO, don’t be rummaging around for CDs, etc, etc[/li][li]With this newly freed attention, look down the road. Look past the car directly in front of you[/li][li]When you notice that you are going at a different speed than the people in your lane, try to match their speed (assuming they are at a reasonable speed…don’t match the racer behind you or the broken down Winnebago ahead)[/li][/ul] There’s a bunch more junk, but I’m already nearly crossing (if not already crossed) the line to a rant.
If everyone was a good driver, and the roads and cars were designed with high speeds in mind, well over 100 MPH would be perfectly safe, as is evidenced by F1, IRL, CART, NASCAR or most any other racing circuit.

Another factor to consider is the handling of your car. If you do have to perform an emergency lane change at 120 mph, will your car continue to hold the road or not? Most high end sports cars that have an upgraded suspension and tires will be able to handle it, but your average econobox is probably going to lose its grip and slide and cause an accident.

Most cars can lock up their tires at high speeds (50mph).

What if you need to brake? I was driving at night at 90 in my little toyota a couple years ago. There was a huge truck in the fast lane doing 55-60mph. It had NO lights on it, so i came flying at it and had to brake really quickly. If i had been going any faster, i would not be typing right now, because i came within 10 feet of that thing.

The speed limits are almost too high right now, because of two reasons: stupid people and inferior performing cars (SUV’s & trucks). If all drivers were good and all cars were corvettes, we wouldn’t have any problems. The lady that ran me off the road on my gsx-r does not need to be driving any faster than 5mph… let alone 80mph.


phaforlifeBy the way, cars are not becoming better at handling. SUV’s and big huge sedans like lincolns and caddys are a danger to everyone on the road. Too much effort is put into making cars have soft drives for a nicer feeling. THe civic has a much softer suspension than 10 years ago, for instance. So, you are wrong, trust me. After driving a formula firebird with racing suspension a lot, you realize how dangerous cars like my other car is (caprice classic wagon).

Putting more of the same people on the road going faster puts all us bikers in much more danger.

I think that robby has hit on part of the limitation inherent in very high automobile speeds. The relative velocity is very demanding and very tiring.

As robby mentions (and I have experienced), driving on the auotobahn at very high speeds is exhilarating but also very fatiguing - the constant threat of a car going 60 mph slower than you appearing in your lane, plus the fact that the stationary trees, signs and various detritus are right next to you makes for an extremely focused, easily tired driver.

Yes, professional racers drive cars at extremely high speeds and very close to one another, but these are professional athletes who finish a race exhausted. Put an everyday driver into Row 3 on the start of a NASCAR race and you’re looking at a huge crash.

As for the OP, I think that even the most experienced, well-prepared driver could not sustain extremely high speeds for longer than an hour or two. Reaction time at extremely high speeds in enhanced by adrenaline, but that can only last for so long.

Instead of talking about tires and braking (nitpick: NOT “breaking”) ability, the real question is a physiological one: how long can a person maintain an alertness level reached only by the use of adrenaline?

I’m guessing an hour or two, but that’s just a WAG. Anyone know for sure?

pilot, you are right on. But you just had to point out the “break” thing didn’t you? Why did you mention it, I am just curious?

Sorry Fuel but that is one of my pet peeves. That and when people type “How did I loose my keys?” I see these typos in otherwise perfect letters and can only conclude that a large portion of the population is confused about the use of these words. Just my little crusade to fight ignorance on ALL fronts!:wink:

But, Dude. Didn’t you see that i spelled it right the next 2-3 times in my next post? Give it up man. I don’t want people pointing out every time i make a mistake, especially since i am not ignorant about spelling, just made a mistake. Leave it alone.

pilot, you are partially correct…

but its not just mentally exhausting, its physically exhausting.

race cars have very very stiff clutches and most of them do not have any type of power steering.

i read somewhere a nascar driver was quoted to say that driving the daytona 500 was like holding on to two 10lb weights with your arms completely outstretched for ~3 hours. not to mention the fact the fireproof (nomex) suits make you uncomfortably hot…

i know its mentally exhausting, but thats not the only factor. most race car drivers are very fit because you have to be up to the physical challenges as well…

All cars should be able to lock their tires in any speed. If you can’t, you need new brakes.

I normally travel in the 120-130 kph range (75-80 mph) whenever traffic permits. Of course I drive a new sport-type car (Matrix XRS) with sport suspension.

Soft suspension, on a highway, isn’t going to matter as much as the driver. As long as the highway is flat and straight, your suspension just needs to work (this doesn’t include highspeed braking).

The real issue (IMO) is that a lot of people out there think slow = safe. So you’ll catch old people in their towncars doing 90 in a 100 kph zone while everyone else is going 120. There are police projects trying to slow people down. This just pisses me off. We don’t need slower highways, we need slow people off the highways. If you can’t follow the speed of traffic, take a secondary road.

Fuel I never intended to point out YOUR mistake. I never mentioned who had made the mistake, I said it was a “Nitpick”. Only when you brought up the subject did I explain why I said it, and even when typing my response I didn’t remember that it was YOU who used the wrong word. I just remembered it being used somewhere in the thread and “Nitpicked” it. That’s all.

Now, of course, I DO remember that Fuel used the wrong word once, and so does everyone else reading this thread. Who cares? I made what I thought was an innocent “nitpick” and I get lectured on not pointing out people’s mistakes.

Before I get lectured by the mods about taking this thing to the Pit I’ll say “Lighten up” and then forget about it.

…OK, it’s forgotten.

To agree with everyone who has already stated:

At comfortable speeds, it’s speed differential rather than actual speed that causes problems. Those in the US who drive the fastest have the most collisions/mile while those who drive the slowest are a close second.

Any vehicle with a high center of gravity, trucks, SUV’s and even tall wagons and minivans, is going to have handling problems, especially at high speeds. Single lane changes can be managed but the abrupt lane change quickly followed by another abrupt attempted lane change back to the original lane too often results in a rollover with a high of gravity vehicle.

Rapid braking at speeds in excess of 80 mph in a typical vehicle sold in the US market can be panic inducing, indeed. My guess is the cost of producing braking systems capable of handling such high speeds on basic transportation is prohibitive given the general needs of the US market. In situations where ABS brakes are optional, not many are willing to pay the extra cost. I suppose even fewer would pay extra for a special high speed braking system for anything that wasn’t a high performance car, whereas making such a feature standard equipment on a typical vehicle would be difficult to justify if not mandated.

Anecdotally, I can attest that averaging in excess of 100 mph for 2-3 hour stretches on non-western Interstates is significantly more exhausting than averaging 75 mph.