Speed Limit Hypothesis

[Tonytone]

Hello everyone, I noticed something while driving & it has to do with speed limits.


So I believe the reason speed limits are set so low is to keep all traffic at a certain maintainable speed on roads. (Yes I know a rookie roadgeek would know that, but we aren't quite finished yet).

The reason for this being for example would be that cars traveling on a highway will go atleast 70MPH if the highway is signed for 55MPH. Many people will still go above 70MPH. Now in a car when you are going at speeds 65+ it will feel pretty comfortable depending on the car and road, you wouldn't notice a difference in your speed if all cars are going as fast as you.

Now lets think of speed limits of 25-45 MPH.

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area. Now I can understand why the speed limit is so low, lots of people, cross streets & alot going on especially in city & neighborhoods . But this stops alot of people from pushing 50 in a unsafe space. But what I've noticed, or atleast in theory is that the speed that we go is actually the speed on the sign more or less. I say this because look at how slow you go when its 25MPH almost feels like your jogging. But then go 35-40 & it feels like 25. Same with highways. When going 80MPH it feels like a cool 65MPH.


Well thats my take on this. Id like to hear what yall think or also have noticed.


iPhone

[SoCal Kid]

I can relate. 65 feels like 40, 70-75 feels like 65, and so on. 

[hotdogPi]

Usually, it's one of two things:

1. They never bothered to update it after NMSL was repealed.

2. It's for "random taxing", as SP Cook calls it.

[Tonytone]

Usually, it's one of two things:

1. They never bothered to update it after NMSL was repealed.

2. It's for "random taxing", as SP Cook calls it.

Yes I also meant to add that, the speed limits are set to where they can give you a ticket if they feel the need to.


iPhone

[X99]

I once got pulled over for coasting from 42 to 45... in a 35. A friend of mine got pulled over for doing 39 in a 35. Top speed limits on the Interstates in my state are 80, and they said they would pull people over for doing even 81, but I've seen people do 90 or 100 for short periods of time on there, and none of them get pulled over.

[webny99]

I'm not sure I understand exactly what your hypothesis is.
Speed limits are set lower than they should be to prevent us from driving at unsafe speeds?
We always feel as if we are going slower than we are?
Our speedometers show us the wrong speed?

I also believe that these two statements conflict:

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area.

But what I've noticed, or at least in theory is that the speed that we go is actually the speed on the sign more or less.

[Tonytone]

I'm not sure I understand exactly what your hypothesis is.
Speed limits are set lower than they should be to prevent us from driving at unsafe speeds?
We always feel as if we are going slower than we are?
Our speedometers show us the wrong speed?

I also believe that these two statements conflict:

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area.

But what I've noticed, or at least in theory is that the speed that we go is actually the speed on the sign more or less.

Sorry for the confusion web. What im saying is, if people are going 80 MPH it is actually 65. But they dont sign the road as 80 so people won't go 100+. 

The speed limits are set low, but in reality the actual speed that everyone goes is the speed they set for the road & expect everyone to go. If that makes sense.


iPhone

[tradephoric]

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area. Now I can understand why the speed limit is so low, lots of people, cross streets & alot going on especially in city & neighborhoods . But this stops alot of people from pushing 50 in a unsafe space. But what I've noticed, or atleast in theory is that the speed that we go is actually the speed on the sign more or less. I say this because look at how slow you go when its 25MPH almost feels like your jogging. But then go 35-40 & it feels like 25. Same with highways. When going 80MPH it feels like a cool 65MPH.


Well thats my take on this. Id like to hear what yall think or also have noticed.


iPhone

Looking at the other extreme, if the speed limit was set to 50 mph through downtown, very few people would feel comfortable driving that fast.  In a downtown area there are pedestrians, bicyclists, people pulling out of on-street parking.  There does reach a point where people will only drive as fast as they feel comfortable, regardless to what the speed limit is.  This is seen along rough sections of road that are in bad need of an overlay.  Even if it is signed for 50 mph, i might go 5 under if it means i can avoid the biggest of the potholes and save my suspension or prevent a blowout. 

[Tonytone]

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area. Now I can understand why the speed limit is so low, lots of people, cross streets & alot going on especially in city & neighborhoods . But this stops alot of people from pushing 50 in a unsafe space. But what I've noticed, or atleast in theory is that the speed that we go is actually the speed on the sign more or less. I say this because look at how slow you go when its 25MPH almost feels like your jogging. But then go 35-40 & it feels like 25. Same with highways. When going 80MPH it feels like a cool 65MPH.


Well thats my take on this. Id like to hear what yall think or also have noticed.


iPhone

Looking at the other extreme, if the speed limit was set to 50 mph through downtown, very few people would feel comfortable driving that fast.  In a downtown area there are pedestrians, bicyclists, people pulling out of on-street parking.  There does reach a point where people will only drive as fast as they feel comfortable, regardless to what the speed limit is.  This is seen along rough sections of road that are in bad need of an overlay.  Even if it is signed for 50 mph, i might go 5 under if it means i can avoid the biggest of the potholes and save my suspension or prevent a blowout.

Yes this is true, Ive noticed it on highways that are signed @70MPH. Most people wont go above that or it feels uncomfortable if you go faster. Or if you know the road or dont know the road you may speed or go less then the MPH posted.

But I've witnessed traffic going 50MPH in a city its very possible. Ask the people here that know the Philly Tri-State area. Chestnut street in Philly is treated like I-95.


I just feel as if the speed limits & our car speedometers are offset.


iPhone

[hotdogPi]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

[Tonytone]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

Could you explain that in regular English please, I still have to complete college.


iPhone

[hotdogPi]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

Could you explain that in regular English please, I still have to complete college.


iPhone

For example, if the speed limit is 65 and the average is 79, increasing the speed limit by 10 (to 75) will increase the average speed by 3 (to 82). At 85, the average speed and the speed limit would be the same.

This is true for freeways; I don't know if it also applies to arterials.

[NoGoodNamesAvailable]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

What's the source on this? I don't necessarily doubt you but that sounds counter-intuitive to me.

[wxfree]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

What's the source on this? I don't necessarily doubt you but that sounds counter-intuitive to me.

I don't know if this is a general finding, but I've seen a study or two that said this is what happened on certain roads where the speed limit increased.  To use an extreme, imagine if the speed limit were increased to 700 mph.  The average driver would not go 710.  You always have idiots who want to go 150 on the freeway and go 80 in a 40, but "speed limit plus X," where X is the margin you believe law enforcement will tolerate, doesn't continue unendingly.  Once you get to the highest speed you're comfortable with, a higher speed limit won't change anything.

Another point is that when the average speed increases, that may be substantially accounted for by people like me who obey the speed limit driving faster since it's now allowed.  It isn't all because of people still going 5 over or 10 over whatever the speed limit is.

Before the statewide speed limit in Texas went up to 75, on the rural Interstates where the limit was 70 most traffic moved at 70 to 75.  After the increase, most of the traffic moves at about the same speed.  At times I pass quite a bit going 75.  That suggests to me that the speed limit is where it should be.  On freeways devoid of traffic, speeds are a little higher, generally 75 to 80.  On those roads I get passed more than pass others at 75.  Where traffic is thicker most people aren't quite comfortable at those speeds.

[michravera]

Increasing the speed limit by 10 mph increases actual average driver speed by 3 mph, unless the speed limit is already set high (such as TX 130). It's not an infinite cycle of increase limit → increase driver speed → increase limit; the two will eventually be the same with enough of an increase.

What's the source on this? I don't necessarily doubt you but that sounds counter-intuitive to me.

I don't know if this is a general finding, but I've seen a study or two that said this is what happened on certain roads where the speed limit increased.  To use an extreme, imagine if the speed limit were increased to 700 mph.  The average driver would not go 710.  You always have idiots who want to go 150 on the freeway and go 80 in a 40, but "speed limit plus X," where X is the margin you believe law enforcement will tolerate, doesn't continue unendingly.  Once you get to the highest speed you're comfortable with, a higher speed limit won't change anything.

Another point is that when the average speed increases, that may be substantially accounted for by people like me who obey the speed limit driving faster since it's now allowed.  It isn't all because of people still going 5 over or 10 over whatever the speed limit is.

Before the statewide speed limit in Texas went up to 75, on the rural Interstates where the limit was 70 most traffic moved at 70 to 75.  After the increase, most of the traffic moves at about the same speed.  At times I pass quite a bit going 75.  That suggests to me that the speed limit is where it should be.  On freeways devoid of traffic, speeds are a little higher, generally 75 to 80.  On those roads I get passed more than pass others at 75.  Where traffic is thicker most people aren't quite comfortable at those speeds.

From what I have seen, Texas posts reasonable speed limits and therefore seldom has to enforce them. California posts some quite unreasonable speed limits and seldom tries to enforce them. I-5 between I-580 and the I-5/CASR-99 split could easily stand an auto speed limit of 85 MPH or certainly 130 km/h with a 10% tolerance (5% for you and 5% for the cop). What I understand is that between CASR-41 and CASR-46 (especially from Utica Ave to Twissleman Rd) CHP mostly writes $1000+ tickets for CVC 22348 (over 100 MPH). They may still bust you for 95, but, if they get you for 100+, they have both enhanced safety and revenue. It costs more in OT pay to get the officer to court than you will be fined, if you change your plea to guilty, if the officer shows up, for a typical 85/70 ticket.
I'm not telling you that its OK to break the law, but a ticket for 99/70 is a ticket in California. 100/70 in California is treated more like a crime.

[roadman65]

It depends on your vehicle. My 2000 Blazer felt that over 60 mph I was traveling 85 mph, but now I got my Kia Forte, when I go 85 mph it feels like 65 mph.

If you have a small car it feels like you are standing still at low speed limits, hence I have to really watch it in school zones as in Florida the speed limit during school hours of going or coming is 15 mph or 20 mph, so I really have to be careful.  The SUV's or mini vans are the other way around due to their big mass and high point of gravity of the vehicle.

Then on the NJ Turnpike with its long and fat pavement striping it really does seem like you are going 40 mph when doing 55 mph due to the illusion created by the longer broken lines.  So my car now would feel like I am in a school zone in FL if I do 55 on the NJ Turnpike.

[vdeane]

Definitely.  Driving the speed limit on the freeways and some surface streets here (especially school zones) feels PAINFUL on my Civic but perfectly fine on the Dodge Caravan we use for some functions at work.  And even 80 feels slow on the NJ Turnpike.

[RobbieL2415]

Just go to "reasonable and prudent" outside urban centers.  Then there's no issue.

[NoGoodNamesAvailable]

Just go to "reasonable and prudent" outside urban centers.  Then there's no issue.

Montana's short-lived experience with this would indicate that there are actually a lot of issues with this approach.

Edit: looking at your post again I can't tell if you're suggesting we get rid of rural speed limits or just offering driving advice.

[Tonytone]

Just go to "reasonable and prudent" outside urban centers.  Then there's no issue.

Funny you say this, New Jersey I feel like does this. They seem to put "65 MPH Zone, fines & something else doubled"  but then you won't see these signs for a while. So its like you can go "reasonable & prudent"  within the safe zones.


iPhone

[Flint1979]

At least around where I live people generally ignore the speed limit and go with the flow. This is common on highways like I-75, I-69, US-10, US-23, US-127, I-96, I-94 and so on. When I'm driving 80 mph it's crazy how much traffic is still passing me doing over 80.

[Tonytone]

According to research All roads have a "Natural speed"  it wont matter if you raise it or lower it.

https://priceonomics.com/is-every-speed-limit-too-low/?utm_source=share&utm_medium=ios_app


iPhone

[michravera]

Hello everyone, I noticed something while driving & it has to do with speed limits.


So I believe the reason speed limits are set so low is to keep all traffic at a certain maintainable speed on roads. (Yes I know a rookie roadgeek would know that, but we aren't quite finished yet).

The reason for this being for example would be that cars traveling on a highway will go atleast 70MPH if the highway is signed for 55MPH. Many people will still go above 70MPH. Now in a car when you are going at speeds 65+ it will feel pretty comfortable depending on the car and road, you wouldn't notice a difference in your speed if all cars are going as fast as you.

Now lets think of speed limits of 25-45 MPH.

When the speed limit is 25 MPH people tend to go 35-40 unless cop presence is heavy in the area. Now I can understand why the speed limit is so low, lots of people, cross streets & alot going on especially in city & neighborhoods . But this stops alot of people from pushing 50 in a unsafe space. But what I've noticed, or atleast in theory is that the speed that we go is actually the speed on the sign more or less. I say this because look at how slow you go when its 25MPH almost feels like your jogging. But then go 35-40 & it feels like 25. Same with highways. When going 80MPH it feels like a cool 65MPH.


Well thats my take on this. Id like to hear what yall think or also have noticed.


iPhone

In the US, the National Maximum Speed Law gave everyone who could drive or who was conscious of others' driving disrespect for speed limits. Roads with design speeds of 80+MPH (and probably many of those were safe close to 100MPH) were, by law, set down to 55MPH. Since 55MPH was the limit on the best, safest, and fastest roads, speed limits on narrower, twistier, less equipped roads had to be lowered to show the difference. The law enacted in 1975 and was only modified so as to permit 65MPH on the best roads in 1985. Finally, the law was repealed in 1995. Now, that's nearly 25 years ago, but the legacy of speed limits that were set too low and the contempt for speed limits won't die for years.

Both California and Texas effectively revived their pre-1974 laws rather quickly. California was a little slow to enact its 70MPH limit everywhere that it could go, but has mostly done so (some areas got much more populated since 1974 and were left at 65MPH). Should most of those 70MPH areas be raised? Sure! Should many of the 65MPH areas be raised. Some should some shouldn't. But, since 65MPH is as high as non-freeways can go under state law, unless the law is changed (and that's tough with as many city people {with "D"s next to their names} in the legislature now who don't see what the rural folks do).

Texas, on the other hand, has given broad authority to its highway department to post reasonable speed limits. 70MPH though downtown Austin on I-35? Sure, except when exits are too close together, etc. 85MPH on intercity tollways? Why not? 60MPH on a flat section of county road in suburban Austin between two hills? What's wrong with that? It's 35MPH on one side and 45MPH on the other side, but 60MPH in the middle. Guess what? Texas State Police have better things to do than pull over drivers just trying to get someplace who aren't a hazard to others. California Highway Patrol has a similar mission. They basically try to do what Texas State Police do, but they look like they are giving you a break.

[vdeane]

Meanwhile, for many parts of the northeast, NMSL may as well have never been repealed.  PA's getting better, but there are many areas where the speed limit drops to 55 for no reason other than the road passed into an area classified by the census bureau as an "urban area", regardless of conditions.  NY didn't even bother to raise even so much as a single mile of interstate above 55 until after NMSL was already repealed and Mario Cuomo was replaced by a Republican.

Meanwhile in Canada, Ontario and Québec have kept their NMSL equivalents to this day, though Ontario will be beginning a small pilot project to raise the limit to 110 on a couple roads.

[hotdogPi]

NY didn't even bother to raise even so much as a single mile of interstate above 55 until after NMSL was already repealed and Mario Cuomo was replaced by a Republican.

On the other hand, they post 55 for roads that would be 35 to 40 in most other states.