Why are cars allowed to go really fast?

I am wondering why street legal cars are allowed to be made that can go anything faster than, say, 90 mph.

While it is nice to see a Porsche that can do 150+ I know of no place on the roads it is legal to do so. If there is no place in the US that allows speeds of over 75 (or whatever the top legal allowed speed is) why do they not mandate limiters that keep a car’s speed to that?

I suppose you could take the limiters off of police cars and of course if you want to race your car on a private track then they could be removed but otherwise. Perhaps set the limiter on the top speed 10 mph over for some wiggle room to pass and such.

Add to the law extreme penalties fro removing or modifying the limiter if on a public street to discourage it. Why isn’t this sort of thing mandated?

I gather that there has been a recent proposal for regulations mandating speed limiters in all automobiles in Australia, but it doesn’t sound as though it was warmly welcomed. I doubt it would be in the US, either.

I don’t have any definitive explanation for why there aren’t any such regulations, but I could guess the following:

  • Speed limiters are a relatively new technology and people aren’t used to thinking of them as a standard, much less mandatory, feature on a car;

  • Many drivers and automotive groups express concern about the safety of speed limiters in situations where, say, you need sudden acceleration to overtake another car;

  • They would probably detract from the perceived excitement and appeal of owning certain types of cars, and this prospect is not attractive to the drivers who like those cars or to the car companies that produce and sell them.

Because we’re Americans, and the first thing that we would do is to rip that sucker out. Anyone else remember mandatory seat-belt interlocks? They didn’t last long.

No doubt people would want to do that hence the idea of making the laws much more harsh for doing just that. Would some people still do it? Probably but you do what you can. You could make it harder to do such a thing as well such as integrating the limiter into the engine’s computer controls so it can’t just be ripped out. Allow places like race tracks that allow people to bring their street cars to race have a temporary override (but one that would require opening the hood and plugging in a computer to a terminal there so it cannot be easily done from inside the car).

To expand the OP a bit it seems there are a number of ideas like this that could be put into new cars to make roads safer. For instance perhaps cars could be fitted with an RFID. If the police are chasing someone in a car with this they could query the ID, ask headquarters for a special code based on the ID and then transmit that to the car which would cause the engine to idle (I put all those steps in there to make it a bit harder for just anyone to beam a shut down code at a car).

Again I know there might be savvy car thieves out there who could foil this but many highspeed chases seem to be people who are not terribly savvy (e.g. a joyrider).

Previous thread on the question

I agree that Americans would not like the thought that their near 175+ mph Posche Carrera would never get above 85 but tough. I know my car can break 120 mph without much problem. It feels nice to know I could go that fast but in reality I have never gotten it much above 90 and even then it is rare. I could live with a limiter in there.

I thought limiters have been around for awhile? I seem to recall a simple limiter on the go-carts I drove at a go-cart track once. Because business was slow the staff was out racing too and they would reach around with one arm to the engine and lift up some lever which would open the cart up to full speed (a speed paying customers were not allowed to go). Granted this seemed a decidedly simple device and obviously easily overcome but still a limiter. One would think such a thing could be managed that was more capable (especially with computer controlled engines).

Is this really an issue? At highway speeds (say 55+) I cannot think of a time where my safety depended upon speeding up quickly. Not all cars are created equally anyway so managing a burst of speed in a given situation might work well for one car but not another that might already be stretched. It seems to me slowing down is the way to go most times.

No doubt this is true and I am sure car companies would fight it but then car companies have fought many regulations that later proved not to hurt sales. No doubt buyers of such cars would be upset too but their desire for a 150+mph car should have no basis on policy where there is never a circumstance where you should be driving over 100 much less 150+.

There are a large number of practical problems with this that I can imagine. I have no factual basis for any of these, just my opinion.

  1. Old cars. Who is going to pay to put a limiter on all the old cars on the road? If you limit all 2008-model cars to 80 mph, the 2007 models will be blowing by them at 90. And that’s a far more dangerous situation than if everyone goes 90.

  2. Speeding on highways isn’t really a big problem in the US. The only justification for this would be to protect other motorists from the nutcases who speed and crash into other cars - who cares if the nutcases kill themselves? If we’re going to stoop to that level of nanny-stateism, let’s ban cigarettes and junk food too.

While I don’t have any statistics handy, I have a feeling that the number of people killed by speeding drivers on the highway is very low.

If the government did want to go for something like this, they’d save far more lives installing breathalyzer interlocks to stop drunk drivers.

  1. It would do nothing about speeding on local roads, which is a lot more deadly than speeding on highways. Local roads have stop signs, sharp curves, blind intersections, kids walking their dog and chasing balls into the street, etc. Highways just go straight.

Hell, it would do nothing about speeding on every road but those with speed limits close the maximum.

  1. Public opinion. A large portion of the population likes to drive, and likes to drive fast. Myself included. It’s the same reason we haven’t outlawed guns. Furthermore, at least here in the northeast, the speed limits are all set 15 mph too low. It’s just understood. I’ve actually been told by cops that, in a 65 mph zone, “anything under 80” is fine with them. And traffic routinely moves at 90 mph on major highways. How would you decide where to set the limiter? On these highways, 75 is a joke.

  2. States rights. The federal government could not mandate this, it would have to be up to the states themselves (because the states set the speed limits on the road within them). And if not all states implemented this, what’s to stop you from buying and registering your car in a state that doesn’t? Plus, you’ll have the same problem as in 1) - cars on the highway will be traveling at different speeds.

  3. Safety. Aside from the safety issues mentioned in 1) and 5) The first time someone driving a speed-limited car tries to pass someone on a two-lane road, and slams into oncoming traffic because the limiter kicked in, the media will go berserk.

There are ways around some of these - you could use GPS to auto-adjust the limiter depending on what road you’re on, you could allow a ten-second overshoot for passing situations, etc. But I think the most important point is that speeding isn’t really a big problem here.

Drunk driving, and stupid ditzy soccer moms putting on makeup while talking on a cellphone, and not checking their blindspot when changing lanes, on the other hand…

You’re assuming that a speed limiter is a good thing. I, and many others, would disagree. Just because you can pass a law, doesn’t mean that you should.

Oh yes, and let’s not forget about the octogenarians who are legally blind in both eyes, have a reaction time measured in seconds, can’t feel the pedals because their feet are numb, and can barely see over the steering wheel.

If you want to something about road safety in this country, stricter driver training and licensing is where to start.

For something that drastic, I think you’d need to make it more than a bit harder. I don’t have enough confidence in auto engineers to add a secure remote shutdown to a car, and causing a car to idle at the push of a button could be very dangerous. It’s also pretty trivial to work around this problem if you want to. RFID can be blocked with aluminum foil.

To the OP, I think that the car manufacturers would be strongly opposed to such a measure, and would lobby against it. It puts them at a competitive disadvantage against their own older products.

There’s a much cheaper and easier way to end all high speed chases. Give a strict “Do not pursue over a given speed” order to all police departments. No high speed chases. You can always catch the guy later withou endangering me walking my dog y’know. Yeah it’s harder, but that’s what they’re paid to do!

It has been awhile sense I have worked on cars, but IIRC most “normal” cars have limiters on them. I know mid 90s mustangs had a 95MPH govenor on them. Manufacturers were doing it for safty. The car is equiped at the factory with tires that are only safe up to 120MPH (My 2001 Dodge 3500) the manufacturer put a limit of 112MPH so that I could not exceed the safty limit of the stock tires. I can go into a Dodge dealer, and have the limit raised/removed, but alot refuse to do it. Mine is still there, and will probably stay till my truck hits 112 before the end of the 1/4 mile. Then it will be time to remove it. I know other manufacturers did the same thing.


I’d say that if police start enforcing speed limits more (like if the limit is 65, you’ll know you can get pulled over for 66) people wouldn’t speed as much. IMO, people speed so much now because they know they can get away with it up to a certain point. I’ve taken my 97 Eclipse up to 100 on the highway once (oops). I regularly go 82 on a highway that has a 70mph speed limit because I won’t get pulled over. Start enforcing the speed limits rigidly with no room for questions, and we wouldn’t need limiters. Only people jonseing for tickets would speed significantly.

And aren’t some really fast European sports cars not street legal in the US?

Limiters are mandated in Japan for trucks over a certain size (8 tons gross weight, I believe). It kicks in at 90 km/h (56 mph). (The legal speed limit is 80km/h = 50mph). Existing trucks were given a few years to get the limiter installed at the truck owner’s expense, on the grounds that the truck owner is the one who benefits most from it (by improved safety). I haven’t driven there since this was implemented, but I’ve heard people say the expressways became much more pleasent to drive on.

Yes, but not because of their speed, only because their manufacturers don’t think it makes economic sense to get them certified here - it’s an extremely expensive process.

The US doesn’t set any limits on maximum horsepower or speed for street-legal cars. The DOT/NTSB only care about emissions, occupant safety, gas mileage, taillight color, and stuff like that.

Most cars really DO have speed limiters.
Actually, the last-generation Chevy Impala police package had a speed limiter that kicked in a few MPH under 130.
Chevy claimed that if allowed to run at its mechanical top speed of 134 it would have overheated, although I’ll note that keeping it under 130 lets them substitute H-rated radials for pricier V-rated rubber.
A recent model of Crown Vic Police Interceptor was governed to 137, but… the car can’t actually go much over 130.
The domestic full-sized vans my company’s service engineers drive are governed to 94 (automaker’s choice, not ours).
The bulk of cars on the road ride on S-rated rubber, and as a result they will be limited to some speed under 112 for liability reasons (106 or 108 are typical cut-offs),

People complain about the NRA and the ACLU. Ha! They are pikers compared to the AARP, and I can all but guarantee you that the moment Congress makes a serious attempt to take mobility and freedom from old people is the day they get voted out en masse. You can be sure that the AARP lets them know it, too.

You can forget all about that one, buddy.

Not because of speed. They’re illegal because they can’t (or won’t) meet safety or emissions standards.

I’m not sure if it is true anymore, but at one time in Japan, cars had to have a speed limiter set at 180 km/h. They also had an irritating alarm that went off if you broke the speed limit.
Somehow, I doubt that the public in the U.S. is clamoring for such a device. I don’t think even Ralph Nader ever called for something like that.

Automation purists view automation as a philosophy. Do you automate for efficiency or for stupidity?

We have had many of arguments on automating control philosophys in the manufacturing enviroment. The ideal appears to be maximum control for the operator not the machine.

In other words, let’s take my BMW. some day it may save my life to take my bimmer well over 130 mph, who knows? I have the power if I need it but I have to be smart about using it [speed], if I ever use it.

It’s like the analogy that guns don’t kill people, but people kill people. Do we hold the gun accountable becuase there are stupid people or do we hold the people accountable. Personally I like my concealed weapons permit and am smart about packing a weapon.

Automobiles have electronic control governors for speed already, it’s just not slowed down to the level you described.

If BMW slowed my bimmer down to 90 MPH I would not buy it. The auto manufactures know this and don’t do it unless forced by government. Having the government tell us how fast we should drive our cars is fixing the symptom not the problem. The problem is we need to drive smart.

Great topic!