Every Road has Three Speed Limits! (Maybe?)
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- เผยแพร่เมื่อ 29 มิ.ย. 2024
- What do you think? Am I on to something? And yeah, #2 "natural speed" is probably the same thing as design speed.
Also, the graph should maybe say "travel time SAVED," not "travel time." (maybe? IDK.)
After publishing the video, I found this document! Time for a follow-up video maybe? highways.dot.gov/media/13901
Some cities do post the 3rd “speed limit.” Signs say “lights times for 18mph” for example.
As long as I'm in front of the guy driving at undulating, variable speeds who keeps braking for no reason (probably on his phone), i have no issue ending up at the same red light as he does. I'd rather be in front of you catching lights than behind you having to constantly adjust to your random stupid nonsense.
fuck yeah man
Truth!
Nothing gets your heart racing faster than going 25 over with cars packed around you going the exact same speed
Sounds the 405 in LA from Irvine to I-5 on a Weekend morning, and they are all insane...
@@argentum530 Close. 880 between Oakland and San Jose mid afternoon
My home town's lights are set up to catch you at every light.... if you are going the speed limit. But if you drive fast you'll get to the next stop light before it turns red.
Stoplight races!
Yep and that increases the speed in which people will drive.
@@MichaelRabbitBass3agreed
Seeing a green light while sitting at a red one right behind it is so tempting to floor it right on green to beat the other light before it changes.
Cities that do this probably have worse speeding problems.
oh wow, good stuff!
i thought one of the "speed limits" was going to be "the speed at which you can expect to not get pulled over", which is typically higher than the posted limit
Thanks!
Where I live, street design intentionally influences the natural speed limit, placing it below the posted speed limit...
This is true, I lived in Fresno, and had a moped, top speed 30, I could drive across town, catching every light green, while sports cars race off at the green, only to wait for me at the light. to get a light ahead, they have to go at least about 70.. since I'm making the light at 30.
This blew my mind bro. Bought to revolutionize humanity!!
I think a challenge you will encounter is how delicate traffic patterns are. My drive takes longer when there is minimal traffic, all it takes is one or two cars on side roads to turn the light red adding minutes to the journey. In moderate traffic my journey is shorter because I maintain right of way and the lights wait for a natural break in traffic.
I'm one of the few people consistently driving below the posted speed limit and am constantly laughing the A*holes blowing past me at waaay above the speed limit, only to catch up to them at a stoplight or traffic.
It is extra bizarre when I am doing 50 in a 75 for a 6 hour long haul stretch and the same person passes me 3+ times.
The effective speed limit in Lancaster, CA is somewhere between 25 to 30 miles per hour
This was interesting and I would like to see more on the subject.
I feel like natural speed is often higher than design speed for rural roads. I have also come across roads where natural speed is way below posted; as in "you need to be a bit crazy to hit the limit" (yay Finnish gravel roads!).
BTW, not all roads are designed. Finland has a lot of rural roads that basically follow old cow paths.
Everything you just said is comparable for rural Arkansas as well!
I visited Finland last year and fell in love. I was able to get from Helsinki to Liesjärvi National Park in the middle of nowhere without a car, and back. Then the next day I was able to get from Helsinki to Tampere (which I fell in love with) without a car.
The Finnish military will be training some of its F35 pilots here in Fort Smith, so I just went on a lark. And now I am just waiting for another opportunity to go back; next time I would like to go further north. Now I am nuts about Finland.
What about an emergency speed limit? The speed limit that a firefighter truck would drive at. A speed that assumes that everyone gives you priority, including traffic lights. Then the speed limit would be the physical max speed of the road+vehicle variables, like just the speed to not grip the car, or rollover in the corners.
True 🤔
Roads here in the u.s be like
Posted speed limit: 40km,25mi
Natural speed limit: 80km,50mi
The data on the graph at the beginning doesn't track, time rises logarithmically (not exponentially as displayed) due to the nature of slow speed travel (doubling e.g. required number of stops below certain threshold speeds). In addition, the effective speed is unfortunately on the other side of the posted speed; In most situations in-city it will be extremely close to the posted speed (Higher effective road speed + equalizers + intentional red light timing cancel to a large degree). In country/unblocked highway situations It can be 20-30 mph faster than posted. Worth noting as well the fourth type: quasi-legal speed. This would be the speed at which officers and other traffic enforcement personnel use as a floor to avoid their tickets getting thrown out; in most states this is 5 over, and is usually set in writing somewhere (ordinances, police training, etc.)
Thanks, this was a really thoughtful reply! There are certainly situations where everything you just typed is true; certainly it's very true for a grand majority of most American-style roadways. Indeed, in practice, many "posted" speed limits are based on a factor (85th percentile) of the "Natural speed limit" of a road.
But in the world of hypotheticals, there are equally plausible situations where the graph can be correct. Have you ever tried to drive a car on Canal street in Manhattan? Additionally keep in mind that that the "effective speed" for bicycles is very high n states with the "Idaho Stop" rule, where cyclists can treat stop lights as stop signs, and treat stop signs as yield signs.
@@MovingintheFort In my state stop signs and stop lights are generally treated as hard and fast. IE: trucks, cars, motorcycles, bicycles all have to come to a hard stop. Bicycles may then proceed, depending on vehicular traffic, but that hard stop is required. It's to ensure that all vehicles' operators stay aware of the traffic around them. Example: a bicyclist ran a stopping and struck a friend's car. The car didn't have a stopping thus having the right-of-way. The bicyclist was transported to the ER. When the police contacted her she was going to get a stopping ticket, but managed to talk herself into a careless driving ticket by claiming she didn't yield to the car because "bicycles always have the right-of-way." Bzzzt, wrong answer! The officer later said she probably should have gotten a reckless ticket as it appeared she was riding faster than the speed limit (easy to do in a residential area/school zone). She stopped just short of trying to claim that bicycles didn't have to obey school zones either.
@@markschneider8815 If you are in the USA, the National Highway and Traffic Safety Administration recommends that your state pass laws allowing bicycles to treat stop signs as yield signs. And here is a source for that: www.nhtsa.gov/sites/nhtsa.gov/files/2023-03/Bicyclist-Yield-As-Stop-Fact-Sheet_032123_v5_tag.pdf
Bicycles have three important safety advantages over cars: (1) we have better visibility, (2) we have better stopping power, (3) we have better agility.
And one disadvantage cyclists have is our acceleration from a dead-stop is horrible compared to cars.
In practice, the chances of a cyclist approaching an intersection, not seeing a car, then not yielding in time, and then not maneuvering out of the way has a much smaller chance of happening than a car approaching the intersection, not seeing the smaller cyclist stopped at the stop-sign (maybe he's behind an A-frame), and crunching him from behind. The inferior acceleration of the cyclist coupled with the weaker stopping power of the car results in death.
There will always be outliers and anecdotes like your friend, but with any statistics involving large numbers, the weight of averages and proven successes in places like Delaware should compel legislatures to at least discuss the so-called "Idaho Stop." The cyclist in your story was speeding and breaking the law, and should be punished for that, but this type of behavior should not restrict the freedom of other law-abiding citizens.
Yup on the country back roads of SC it's 55 but usually go 70 instead
Thanks for your confession. I will be sure to be sending a speeding ticket to your mailbox in the next 5-10 business days.
is that Main Street in Preston!?
It's Fort Smith, Arkansas!
@@MovingintheFort you said Idaho and gave me confirmation bias. You should do a street view of PReston :o
@@gamersroost Haha, sorry. Idaho revolutionized bicycle traffic laws. The "Idaho Stop" allows cyclists to treat stop lights as stop signs, and to treat stop signs as yield signs. It's what makes it possible for bicycles to, depending on road conditions, reach their destination more quickly than cars. Mathematically identifying areas where it is possible to ride a bike faster than drive a car is what draws my interest to this project.
There are 4 types, there is also the speed minimum limit, like in Alabama on the interstate the minimum speed is 50 MPH.
Regardless I tend to go 55 MPH on the interstate, only exception is on I-10 in Texas where the limit is 80 MPH when it's busy, then I go 60 MPH in the right lane.
1:37 wait so the fastest way to get to your destination is to go 0 mph?
The graph is a hypothetical scenario, which I believe *may* exist, to show that some travel routes (not necessarily roadways, but also roadways) have a point at which traveling any faster produces diminishing return. I.e., you can go to 20mph faster than usual, but because of the timing on the light ahead of you, you're just going to have to put on your brakes and wait a minute for the red light to turn green, when you could have spent that minute driving at a slower speed instead. I'm not necessarily advocating for anything here, I'm just trying to find out if the math to calculate this is possible.
@@MovingintheFort still, the graph should go up instead of down the slower you go than your effective speed, basically approaching infinity at 0mph as you’re not moving. Not to mention that you‘ll have different scenarios, I don’t know how it is in the US but here in Germany we have a lot of roads where you‘ll basically always get a green light if you drive the speed limit, the traffic lights are timed so they keep the flow going. But even if thats not the case you could get lucky and benefit from going faster by slipping through before it goes red… the optimal speed probably constantly fluctuates depending on what the current situation is.
Also this really only works in dense city centers where you absolutely have to use traffic lights, further outside there’s space for roundabouts which are way more efficient at not making people stop and anywhere there’s a stretch of open road long enough you‘d get a benefit.
@@Simoxs7 Oh, yes, you're absolutely right about that! thanks for catching.
You have it backwards.
Let's say the red light up ahead gives you a green light every minute.
If you can speed up so that you catch the tail end of a green light, you will have shaved 1 minute off your travel time.
If you were to travel at ludicrous speeds you could possibly catch the tail end of the light even before that one and shave 2 minutes off your time.
Doesnt sound like much but 1-2 minutes saved over the course of 10 lights is 10-20 minutes saved.
Even better is if the city's red lights have a green wave type feature that guarantees green lights for a particular stretch of road as long as you maintain a certain speed!
Derek, this video is about a hypothetical mathematical algorithm. I'm not sure what you think I have backwards. Can you expand on what you mean?
Even if you drive a spaceship at the speed of light, I can design a traffic-light system that gets you to your destination at basically the same time as someone who is walking. Heck, I could even give your spaceship an hour head-start and still have the walker tie you at the finish line.
@MovingintheFort You said that there is a maximum speed in which going faster won't save any time.
I was simply saying that if going faster let's you get to the next stop light before it turns red there isn't a maximum speed in which going faster doesn't save time short of being able to make every light when it is green.
Having said that, these speeds may not be legal and could be a trip straight to jail if caught if it required you to go 130 mph to make the next light.
@@Derekzparty Seems like Derek is describing a situation where the effective speed limit ranges between low and high and Fort is describing engineering the situation so the effective speed limit is safe. If the next stop light is already red when than the one you speed out of turns green, there is no speed at which you can beat the next light
@Billionth_Kevin This is true but in that case the goal would be to slow down and arrive at the red light a few seconds after it turns green so that you can maintain your speed through the intersection and hope future lights are synced better.
The reason people drive over the speed limit is because they know that most cops don't calibrate their radar, so they can argue in court they weren't speeding.
Bike infrastructure? Who cares.
Hello, this channel is primarily focused on long-term revenue and expense modeling for municipal finances in Fort Smith, Arkansas, with a specific focus on transportation of all modalities. If it's mathematically proven that bicycles can move people faster for less money, then the principle of fiscal conservatism compels us to explore that alternative.
Forward this over to @RoadGuyRob This is an interesting subject for sure!