I mean theoretically adding a lane or two should allow more cars to flow through, or would bad drivers still cause bottlenecks/gridlock despite the added capacity?
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When freeway traffic is four lanes going 80 mph, the freeway isn’t the bottleneck. The exits are the bottlenecks. There is a benefit to expanding two lanes to maybe three or four. But expanding four lanes into six or seven just means that one guy who’s about to miss his exit will slow down and cross six lanes at the last second. There’s a real benefit to improving exits, adding lanes or device scanners to toll booths, anywhere people have to NOT “drive 80mph in a straight line”. Those are your bottlenecks.
When freeway traffic is four lanes going 80 mph, the freeway isn’t the bottleneck. The exits are the bottlenecks. There is a benefit to expanding two lanes to maybe three or four. But expanding four lanes into six or seven just means that one guy who’s about to miss his exit will slow down and cross six lanes at the last second. There’s a real benefit to improving exits, adding lanes or device scanners to toll booths, anywhere people have to NOT “drive 80mph in a straight line”. Those are your bottlenecks.
More lanes don’t ease congestion. There’s two main reasons, and one of them is indeed bottle necks. Even if you do widen a road, unless you widen each and every road, or at least most of the roads that connect to it, you will create bottlenecks that will back up into the widened road. The second reason is the fact that if you widen a road, people will assume it will be less congested, but then that just means more people will elect to use that road, and the extra capacity quickly fills up.
Lastly, bad drivers can indeed create congestions and you’d be surprised just easy it is. 5-6 cars with dumb drivers can easily block an entire boulevard or highway, if they stagger themselves just right across the lanes, which for some reason people unwittingly do very often.
The only way to truly solve traffic is to enhance public transportation infrastructure and maximise its efficiency along with roads, but that’s a utopian scenario because that’s often not possible to retroactively do on existing cities that were not built with it in mind and often costs or transit times ultimately push people away. What cities do instead is try to penalise car usage without offering a better alternative which ends up with everything just being a huge mess and transit costs rising across the board.
More lanes don’t ease congestion. There’s two main reasons, and one of them is indeed bottle necks. Even if you do widen a road, unless you widen each and every road, or at least most of the roads that connect to it, you will create bottlenecks that will back up into the widened road. The second reason is the fact that if you widen a road, people will assume it will be less congested, but then that just means more people will elect to use that road, and the extra capacity quickly fills up.
Lastly, bad drivers can indeed create congestions and you’d be surprised just easy it is. 5-6 cars with dumb drivers can easily block an entire boulevard or highway, if they stagger themselves just right across the lanes, which for some reason people unwittingly do very often.
The only way to truly solve traffic is to enhance public transportation infrastructure and maximise its efficiency along with roads, but that’s a utopian scenario because that’s often not possible to retroactively do on existing cities that were not built with it in mind and often costs or transit times ultimately push people away. What cities do instead is try to penalise car usage without offering a better alternative which ends up with everything just being a huge mess and transit costs rising across the board.
Neither:
Drivers are individuals who each have a comfort level with the amount of traffic they are willing to drive in, and they also have requirements for when they need to arrive. As a whole they balance these two factors and totaled together across a metropolitan area you get the amount of traffic you see at rush hour.
If you widen a road (taking up space that is currently business or homes) the equation updates and more drivers leave earlier and you still have the same amount of congestion at rush hour in addition to more pavement to maintain using more tax money and longer trips because you had to move homes and businesses out of the way.
You run out of reasonably taxable income to maintain the widened roads before you can widen roads enough to have no congestion.
Neither:
Drivers are individuals who each have a comfort level with the amount of traffic they are willing to drive in, and they also have requirements for when they need to arrive. As a whole they balance these two factors and totaled together across a metropolitan area you get the amount of traffic you see at rush hour.
If you widen a road (taking up space that is currently business or homes) the equation updates and more drivers leave earlier and you still have the same amount of congestion at rush hour in addition to more pavement to maintain using more tax money and longer trips because you had to move homes and businesses out of the way.
You run out of reasonably taxable income to maintain the widened roads before you can widen roads enough to have no congestion.
I think looking at the reason why traffic jams are created will explain a lot why adding more lanes would not fix it.
Traffic jams, or slow traffic, are caused by multiple reasons, the obvious one is a car crash, but beside that traffic can be slow for reasons like lanes are reducing from 4 to 2, exit lanes, poor engineering of lane adding or deduction, poor engineering because engineer had no other option because of environmental issue or sometimes political issues, some people are not the greatest drivers and drive like 60mph where 80 is allowed, they do that for multiple reasons (let’s not get into those reasons). Bad weather conditions, poor road quality, …..
The list goes on and on.
Imagine people would drive similar like soldiers walk in group when they are marching, everyone at the same speed and same pace, driving would be a walk in the park.
Self driving cars could do that, marching like soldiers.
I think looking at the reason why traffic jams are created will explain a lot why adding more lanes would not fix it.
Traffic jams, or slow traffic, are caused by multiple reasons, the obvious one is a car crash, but beside that traffic can be slow for reasons like lanes are reducing from 4 to 2, exit lanes, poor engineering of lane adding or deduction, poor engineering because engineer had no other option because of environmental issue or sometimes political issues, some people are not the greatest drivers and drive like 60mph where 80 is allowed, they do that for multiple reasons (let’s not get into those reasons). Bad weather conditions, poor road quality, …..
The list goes on and on.
Imagine people would drive similar like soldiers walk in group when they are marching, everyone at the same speed and same pace, driving would be a walk in the park.
Self driving cars could do that, marching like soldiers.
Traffic can be modeled as a compressible fluid, which is one where the particles(cars) have a slight attractive force from a distance(you slowly catch up to the car in front of you), and a strong repulsive force up close(you slam on the brakes when the car in front is too close).
You can model a highway using compressed air and pipes(or have a computer pretend to do so and get the same results) of particular sizes to model as lanes on a freeway.
What’s counterintuitive about modeling traffic is that we wish it could be modeled as incompressible flow, because that would mean when a bottleneck happens, the particles/cars should *speed up*, and there would be no shockwave slowing down everyone. But that doesn’t happen because people drive how they drive.
Adding lanes will allow for more cars to travel through the same section of roadway per second/minute/hour, and this should help increase the space between cars, which means fewer people using their brakes and causing shockwaves(you can model exactly where these will happen based on the configuration of the lanes). But this isn’t considering the fact that more people will drive on the road if more cars can drive on it, and fewer people will use surface streets.
Some ways you can increase the throughput of traffic:
-add lanes, so there is more space between each car
-design your lanes such that there isn’t a massive amount of cars all trying to get off the same exit while cars entering the freeway are trying to get into the fast lanes, opposing the drivers trying to exit. This causes lots of shockwaves that otherwise wouldn’t exist if traffic designers were more intentional about their designs.
-occupy as much lane area as possible, which means staying in the disappearing lane until the merge with the adjacent lane happens(this one is counterintuitive because most drivers want to merge as soon as possible, which reduces the effective lane area that can be occupied by cars. Iirc Norway advises their new drivers to stay in the merging lane until the last second, something an American might road rage at another driver for doing)
And lastly, changing how the particles(cars) interact with each other. This means reducing following distance and reducing your reaction time. If everyone drove like the start of an f1 race, not braking until they are right on the driver in front’s ass, and accelerating as soon as the car in front begins to move, shockwaves that cause slow downs would get sucked *through* the bottleneck and would cease to exist.
Obviously the last part is super unsafe and not advisable, but it would make traffic go faster, at least until the wreck happens.
Traffic can be modeled as a compressible fluid, which is one where the particles(cars) have a slight attractive force from a distance(you slowly catch up to the car in front of you), and a strong repulsive force up close(you slam on the brakes when the car in front is too close).
You can model a highway using compressed air and pipes(or have a computer pretend to do so and get the same results) of particular sizes to model as lanes on a freeway.
What’s counterintuitive about modeling traffic is that we wish it could be modeled as incompressible flow, because that would mean when a bottleneck happens, the particles/cars should *speed up*, and there would be no shockwave slowing down everyone. But that doesn’t happen because people drive how they drive.
Adding lanes will allow for more cars to travel through the same section of roadway per second/minute/hour, and this should help increase the space between cars, which means fewer people using their brakes and causing shockwaves(you can model exactly where these will happen based on the configuration of the lanes). But this isn’t considering the fact that more people will drive on the road if more cars can drive on it, and fewer people will use surface streets.
Some ways you can increase the throughput of traffic:
-add lanes, so there is more space between each car
-design your lanes such that there isn’t a massive amount of cars all trying to get off the same exit while cars entering the freeway are trying to get into the fast lanes, opposing the drivers trying to exit. This causes lots of shockwaves that otherwise wouldn’t exist if traffic designers were more intentional about their designs.
-occupy as much lane area as possible, which means staying in the disappearing lane until the merge with the adjacent lane happens(this one is counterintuitive because most drivers want to merge as soon as possible, which reduces the effective lane area that can be occupied by cars. Iirc Norway advises their new drivers to stay in the merging lane until the last second, something an American might road rage at another driver for doing)
And lastly, changing how the particles(cars) interact with each other. This means reducing following distance and reducing your reaction time. If everyone drove like the start of an f1 race, not braking until they are right on the driver in front’s ass, and accelerating as soon as the car in front begins to move, shockwaves that cause slow downs would get sucked *through* the bottleneck and would cease to exist.
Obviously the last part is super unsafe and not advisable, but it would make traffic go faster, at least until the wreck happens.
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