Why widening a road (or building more roads) almost never reduces traffic congestion (major, compared)

[Wilton2ParkAve]

Originally Posted by Phyxius

People migrated to suburbs because cities were terrible places to live in. They were crowded, polluted, limited housing. Suburbs exist well before highways. There always been traffic congestion. The only problem is that highways did not reduce traffic congestion overall. No one bother to find out how will this affect the adjacent streets that intersect with the highways.

Everyone thinks transit is the ultimate solution. Everyone does not live near a transit station. Transit does not stop at every building or neighborhood. Everyone can't live close to their jobs. Some people still have to drive to the nearest station and they don't have unlimited parking. Transit takes a small percentage of drivers off the road. Relying on transit alone will not make a different. Someone else on the highway will simply take their place and the cycle repeats itself. Everyone don't find transit to be any use to them no matter what. Everyone has different preferences and they need to be acknowledge.

The problem with widening roads is that the construction take too long. Traffic is growing while they are wasting 5-7 years to study, fund and build the road. The traffic is already there. The data collected initially is outdated by the time construction is completed. No one bothers to update the data or anticipate growth when it comes to roads. As for transit, planners tend to underestimate the cost Then they come up with some baseless claim to convince others that this is a good idea when it's doomed from the start.

Sheer brilliance. Thank you for saying it so eloquently.

[darkeconomist]

Originally Posted by Patricius Maximus

Rerouting happens anyway and the urbanists' solution is nearly always to punish drivers via "traffic calming" devices, never to improve the clogged artery so it isn't clogged. As for "no double standard", a double standard is being applied when you just decree that "there are enough lane-miles" when the plain fact of current demand far exceeding the supply of lane-miles suggests there is not enough to accommodate what the public wants to do on these roads. That assessment represents a bias against drivers in favor of riders, pedestrians, and bicyclists; and given how transportation is currently managed in this economy it also represents a political choice based upon a subjective judgment of value. I have no problem with such choices and indeed I consciously do just that myself, but I do have a problem with people pontificating for it as if it's something other than that.



Indeed, and then that is used as an argument that "more roads won't work" when the proximate cause of congestion getting worse is the very opposition to new roads environmentalists, penny-pinchers, and NIMBYs hold to on the premise of "more roads won't work" . What really annoys me is how no major city in modern times has even tried to eliminate congestion in even the smallest area, which means that any theory remains less tested than we'd all like; the closest any American city has come to testing the "yes we can eliminate congestion" theory is (via dumb luck) Kansas City, which has the most freeway lane-miles per capita of any city in North America, which also happen to rank among the least-congested urban freeways ..

This is all false.

The problem we face is pricing of a finite ("scarce") resource. If we under-price it, in this case providing free access to freeways, then we are incentivized to consume as much of that resource as we are able and we are forced to use other, less efficient, metrics to value that resource.

Traffic calming measures are put in place where vehicles and other users--pedestrians and cyclists, namely--are in conflict to the point that those other users are being maimed or killed. This isn't to harm or punish drivers, but to, more often than not, bring streets to safe driving speeds.

We have spent hundreds and hundreds of billions of dollars in the last 60 years building and expanding our high-volume, high-speed roadways--interstates, freeways, highways, expressways, parkways, etc.--so it doesn't hold true that we, as a society, haven't tried and tried again to keep up with "demand." In addition, we've spent billions and billions on public transit projects to reduce congestion on our roadways.

At the same time, land is also a scarce resource, so adding lane-miles in built out areas means taking land from other uses. In some areas that's become so expensive as to become impossible, near as makes no difference.

Let's bullet point this:

• Land is finite and fully consumed in cities
• And city, county, and state budgets are finite
• Meanwhile, arterial roadway demand is based on the low, low price of $0 for access
• Thus, roadway demand > possible supply

We simply cannot build our way our of congestion, because, once again, congestion is a symptom, not the illness and the real world places finite limits on what we can do.

[nybbler]

Originally Posted by darkeconomist

We have spent hundreds and hundreds of billions of dollars in the last 60 years building and expanding our high-volume, high-speed roadways--interstates, freeways, highways, expressways, parkways, etc.--so it doesn't hold true that we, as a society, haven't tried and tried again to keep up with "demand." In addition, we've spent billions and billions on public transit projects to reduce congestion on our roadways.

Most of the roads were built in the FIRST part of those 60 years.

[nei]

Have any major roads been built in the nyc area post 1970?

[IC_deLight]

Originally Posted by darkeconomist

This is all false.

The problem we face is pricing of a finite ("scarce") resource. If we under-price it, in this case providing free access to freeways, then we are incentivized to consume as much of that resource as we are able and we are forced to use other, less efficient, metrics to value that resource.

Don't think your model is an accurate portrayal of reality. Freeways aren't consumables.
Because air is free are you "incentivized" to consume as much as you are able - or do you simply breathe? Do you intend to charge pedestrians for the use of sidewalks? After all they will "consume" as much as they are able so long as it is free....

[stateofnature]

Originally Posted by IC_deLight

Don't think your model is an accurate portrayal of reality. Freeways aren't consumables.
Because air is free are you "incentivized" to consume as much as you are able - or do you simply breathe? Do you intend to charge pedestrians for the use of sidewalks? After all they will "consume" as much as they are able so long as it is free....

My breathing air doesn't take away air from anybody else. My driving on a freeway does take away space on that freeway from somebody else. The marginal cost of my driving is more congestion and more air pollution. We should price those externalities with tolls so people use freeways more efficiently.
If you can point to negative externalities that come from sidewalks, I'd be happy to consider charging people for the use of sidewalks. But in general, aside from Times Square on New Year's Eve, there aren't problems with sidewalk congestion massively slowing people down.

It seems like some people think driving is some God-given right that should always be free. I don't get what makes driving so special.

[nybbler]

Originally Posted by stateofnature

The marginal cost of my driving is more congestion and more air pollution. We should price those externalities with tolls so people use freeways more efficiently.

1) Congestion is not an externality.
2) Air pollution can be covered with fuel tax... why a toll?

[nei]

Originally Posted by nybbler

1) Congestion is not an externality.
2) Air pollution can be covered with fuel tax... why a toll?

Why not? Agree with (2).

[Katarina Witt]

Originally Posted by darkeconomist

This is all false.

The problem we face is pricing of a finite ("scarce") resource. If we under-price it, in this case providing free access to freeways, then we are incentivized to consume as much of that resource as we are able and we are forced to use other, less efficient, metrics to value that resource.

Traffic calming measures are put in place where vehicles and other users--pedestrians and cyclists, namely--are in conflict to the point that those other users are being maimed or killed. This isn't to harm or punish drivers, but to, more often than not, bring streets to safe driving speeds.

We have spent hundreds and hundreds of billions of dollars in the last 60 years building and expanding our high-volume, high-speed roadways--interstates, freeways, highways, expressways, parkways, etc.--so it doesn't hold true that we, as a society, haven't tried and tried again to keep up with "demand." In addition, we've spent billions and billions on public transit projects to reduce congestion on our roadways.

At the same time, land is also a scarce resource, so adding lane-miles in built out areas means taking land from other uses. In some areas that's become so expensive as to become impossible, near as makes no difference.

Let's bullet point this:

• Land is finite and fully consumed in cities
• And city, county, and state budgets are finite
• Meanwhile, arterial roadway demand is based on the low, low price of $0 for access
• Thus, roadway demand > possible supply

We simply cannot build our way our of congestion, because, once again, congestion is a symptom, not the illness and the real world places finite limits on what we can do.

Just to ditto what someone else said, freeways are not "consumable" in the way that gas is, or the Ogallala Aquifer water, e.g. once you use it up it's gone. The economic model you're using does not fit the situation.

[nybbler]

Originally Posted by nei

Why not? Agree with (2).

Because the costs of congestion -- specifically the delays caused by congestion -- are borne by the same people who cause it.