Rural Freeways That Need Six Lanes

[mgk920]

I'm surprised that the WV turnpike needs six lanes.

There is no other good way to get across the state in that direction.

Also, IMHO, the I-77/81 duplex in Virginia needs rebuilding into a 'local/express' setup, with a six-lane I-81 being the inner 'express' lanes and I-77 being the outer 'local' lanes.

Mike

[webny99]

Today is a good peak travel day to take a look on Google Maps and see some of the 4-lane freeways that need 6-lanes and have congestion issues on heavy travel times.

Indeed. Yesterday afternoon certainly contributed to the case for widening the Thruway, with at least three separate incidents causing major delays between Buffalo and Syracuse. I could tell volumes streaming through the Williamsville toll barrier were too high to be sustained, and sure enough, within 20 minutes after I passed by around 4 pm, an incident had been reported just east of NY 78, backing traffic up 5+ miles and onto both free I-90 and I-290 west of Exit 50.

[roadman]

The one thing that I have noticed is that the more lanes built just attracts more traffic.  I have witnessed this in Florida, Georgia, and Tennessee.  So why bother in the first place.

Attracts more traffic? The traffic is already there. Adding more lanes is adding more capacity for traffic to move.

I read a book called "traffic" by Tom Vanderbilt (would recommend it to any roadgeek), and the "more lanes means more cars" idea was a central concept of the book. It is true, it's not a cheeky lie. That being said, it doesn't mean that freeways should never be widened, because there is a time and place where that is the best option.

It's often referred to as Parkinson's Law of Traffic Generation, and was first verified with the construction of the Triborough Bridge in 1936.

[Flint1979]

I-75 southbound was backed up yesterday at a point where it goes from six lanes to eight lanes for some reason it was backing up and backing I-675 up into downtown Saginaw.

I got caught in a traffic jam on US-127 southbound yesterday north of St Johns in the stretch where it goes down to a divided highway. I was on M-57 and went to turn south and by the time I saw the traffic was backed up I was already coming down the on ramp. That stretch is the only stretch of US-127 north of Jackson that isn't freeway. It's freeway from Jackson to Grayling.

[sprjus4]

I got caught in a traffic jam on US-127 southbound yesterday north of St Johns in the stretch where it goes down to a divided highway. I was on M-57 and went to turn south and by the time I saw the traffic was backed up I was already coming down the on ramp. That stretch is the only stretch of US-127 north of Jackson that isn't freeway. It's freeway from Jackson to Grayling.

Any plans to finish the gap? Traffic counts look around 20,000 AADT with around 10% large trucks. It's probably not a big priority - but with that amount of traffic it could be necessary in 10-20 years.

[sprjus4]

I'm surprised that the WV turnpike needs six lanes.

There is no other good way to get across the state in that direction.

Also, IMHO, the I-77/81 duplex in Virginia needs rebuilding into a 'local/express' setup, with a six-lane I-81 being the inner 'express' lanes and I-77 being the outer 'local' lanes.

Mike

Only issue is space and the close proximity of the frontage roads. That stretch of roadway was originally a 4-lane divided US-11 until expanded into a 6-lane freeway with continuous frontage roads on either side and tight interchanges in the late 80s.

It does have a 40 foot median though, and could be widened to 8-lanes. That would clear up a lot of the issues IMO.

[Flint1979]

I got caught in a traffic jam on US-127 southbound yesterday north of St Johns in the stretch where it goes down to a divided highway. I was on M-57 and went to turn south and by the time I saw the traffic was backed up I was already coming down the on ramp. That stretch is the only stretch of US-127 north of Jackson that isn't freeway. It's freeway from Jackson to Grayling.

Any plans to finish the gap? Traffic counts look around 20,000 AADT with around 10% large trucks. It's probably not a big priority - but with that amount of traffic it could be necessary in 10-20 years.

It was suppose to be part of Michigan's section of I-73 but that highway will probably never happen at least in Michigan.

It's not horrible in that stretch but it goes down to 65 mph use to be 55 mph which wax even worse than it is now. Most traffic still does about 70 through there too. The lanes remain the same too. I think they should just make it 75 mph all the way through. It doesn't really cross too many major roads and has an interchange at M-57 with M-57 crossing it on an overpass.

[sprjus4]

I think they should just make it 75 mph all the way through.

Pulling a Texas I see 

[Scott5114]

The one thing that I have noticed is that the more lanes built just attracts more traffic.  I have witnessed this in Florida, Georgia, and Tennessee.  So why bother in the first place.

Attracts more traffic? The traffic is already there. Adding more lanes is adding more capacity for traffic to move.

I read a book called "traffic" by Tom Vanderbilt (would recommend it to any roadgeek), and the "more lanes means more cars" idea was a central concept of the book. It is true, it's not a cheeky lie. That being said, it doesn't mean that freeways should never be widened, because there is a time and place where that is the best option.

It's often referred to as Parkinson's Law of Traffic Generation, and was first verified with the construction of the Triborough Bridge in 1936.

And it's just as much bullshit now as it is then. Cars don't spawn out of thin air like koopas in Super Mario World.

Nobody is going down to the dealership and buying six cars for their family because the road got widened. Whenever you widen a road and traffic increases, it's because those cars were taking other routes and are now choosing the widened road. They are leaving an empty space on the road they were using before. Traffic is the same, the pattern is just changing.

[Plutonic Panda]

The one thing that I have noticed is that the more lanes built just attracts more traffic.  I have witnessed this in Florida, Georgia, and Tennessee.  So why bother in the first place.

Attracts more traffic? The traffic is already there. Adding more lanes is adding more capacity for traffic to move.

I read a book called "traffic" by Tom Vanderbilt (would recommend it to any roadgeek), and the "more lanes means more cars" idea was a central concept of the book. It is true, it's not a cheeky lie. That being said, it doesn't mean that freeways should never be widened, because there is a time and place where that is the best option.

It's often referred to as Parkinson's Law of Traffic Generation, and was first verified with the construction of the Triborough Bridge in 1936.

saying it was verified is a misnomer or better put simply untrue.

[webny99]

The one thing that I have noticed is that the more lanes built just attracts more traffic.  I have witnessed this in Florida, Georgia, and Tennessee.  So why bother in the first place.

Attracts more traffic? The traffic is already there. Adding more lanes is adding more capacity for traffic to move.

I read a book called "traffic" by Tom Vanderbilt (would recommend it to any roadgeek), and the "more lanes means more cars" idea was a central concept of the book. It is true, it's not a cheeky lie. That being said, it doesn't mean that freeways should never be widened, because there is a time and place where that is the best option.

It's often referred to as Parkinson's Law of Traffic Generation, and was first verified with the construction of the Triborough Bridge in 1936.

And it's just as much bullshit now as it is then. Cars don't spawn out of thin air like koopas in Super Mario World.
Nobody is going down to the dealership and buying six cars for their family because the road got widened. Whenever you widen a road and traffic increases, it's because those cars were taking other routes and are now choosing the widened road. They are leaving an empty space on the road they were using before. Traffic is the same, the pattern is just changing.

... or in the case of some of the fast-growing cities out West, traffic is increasing with population, and the widening was most likely a response to the increasing traffic.

[skluth]

The one thing that I have noticed is that the more lanes built just attracts more traffic.  I have witnessed this in Florida, Georgia, and Tennessee.  So why bother in the first place.

Attracts more traffic? The traffic is already there. Adding more lanes is adding more capacity for traffic to move.

I read a book called "traffic" by Tom Vanderbilt (would recommend it to any roadgeek), and the "more lanes means more cars" idea was a central concept of the book. It is true, it's not a cheeky lie. That being said, it doesn't mean that freeways should never be widened, because there is a time and place where that is the best option.

It's often referred to as Parkinson's Law of Traffic Generation, and was first verified with the construction of the Triborough Bridge in 1936.

And it's just as much bullshit now as it is then. Cars don't spawn out of thin air like koopas in Super Mario World.
Nobody is going down to the dealership and buying six cars for their family because the road got widened. Whenever you widen a road and traffic increases, it's because those cars were taking other routes and are now choosing the widened road. They are leaving an empty space on the road they were using before. Traffic is the same, the pattern is just changing.

... or in the case of some of the fast-growing cities out West, traffic is increasing with population, and the widening was most likely a response to the increasing traffic.

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts. People will drive more when more highway space is available. Some extra traffic will be from former carpoolers because driving has become easier. Some traffic will be people taking more trips they may have avoided because there's more space on the road. Some traffic will come from other roads that are now not as quick as the new wider road. There are dozens of reasons the lanes will fill again, none of which require the spontaneous appearance of koopas.

This doesn't change the need for many highway widenings. There are still far more highways that need six lanes than there is money and the will to widen them. I-10 between Indio and the western Phoenix suburbs desperately needs widening to six lanes and can be justified by traffic count, the high percentage of trucks combined with the steep grades approaching Chiriaco Summit, and the high number of accidents for a rural interstate. I can name a dozen other rural interstates that also need widening. Traffic would undoubtedly increase on any of these interstates should they be widened, much of it induced by the widening. That wouldn't change the need for widening those interstates. But there is a direct relationship that is scientifically proven.

[Flint1979]

I know this is about rural areas but for an urban area I-94 is in serious need of not only repairs but it also needs to be widened like 20 years ago. This pretty much involves the stretch in Wayne and most of Macomb County. I've mentioned several times how I-94 needs to be widened between Ann Arbor and Benton Harbor as well. MDOT is slower than molasses in January at getting anything done.

[webny99]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.

More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

[hotdogPi]

Let's say that a 4-lane road has 20k AADT and it gets widened to 6 lanes. Even if the ridership increases, it shouldn't multiply by 1.5× solely due to the widening. If it increases to 25k, it's still a benefit.

[sprjus4]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.

More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

Here's the problem: that street doesn't serve anything else besides your neighborhood and has no cut through.

A lot of times, neighborhoods are surrounded on either side by two major roads. People use the many residential streets that go between the two major roads as a cut over. If one of those roads was expanded to four-lanes, chances are it would generate more traffic as it would be a more appealing route rather than the other 2-lane residential streets.

[MikieTimT]

In Arkansas, at the very least the segment of I-40 between Little Rock and Memphis.  At every section, AADT runs at least 31,000 with several stretches much greater than that.  To make matters worse, quite literally half of the traffic on road is truck traffic.  Lots of rolling roadblocks as governed trucks attempt to overtake each other at less than a 2MPH differential.

[skluth]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.

More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

An AADT of 320 shows the area is sparsely populated and likely won't need widening for a very long time. Try again when the population reaches several thousand. Not relevant.

[Scott5114]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.

More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

An AADT of 320 shows the area is sparsely populated and likely won't need widening for a very long time. Try again when the population reaches several thousand. Not relevant.

So you're saying there has to be an already-existing need for widening for traffic to be "induced"?

[jakeroot]

Cars don't spawn out of thin air like koopas in Super Mario World.

No, but people do (sort of). The population of the US has grown by 17% over the last twenty years. How are those people getting around? Based on our investments in transportation over the last forty years, I'm going to guess, largely, single-occupancy vehicle.

So you're saying there has to be an already-existing need for widening for traffic to be "induced"?

Induced demand is largely aimed at people who are going to live in a certain area, but don't yet. How are they going to get around "the city"? It can be aimed at the current population, especially in areas with very bad traffic.

Consider this:

Someone in City A rides the train to work, because traffic is miserable. They own a car, but they consider it a waste of time (and money) to drive; they have relatively easy access to the train via a local bus a few blocks from their home. City A officials then widen a portion of road that was an essential part of their commute; they switch back to driving because their commute now takes about 25% less time. Their fuel economy is now higher as well, reducing their fuel usage (cheaper).

City A officials widened this road, with the hope that it would reduce the congestion. Perhaps it will, short term. But that high-speed road is now a very attractive option for people who never used that road, stopped using it previously, or just moved to the area. Basically, the road will (ultimately) end up serving people that don't currently use the road. But what if we just don't widen the road? What if that road was just a permanently crappy option? We could widen the road, but if the population is growing, and we widened the road as a response to that, at what point is the freeway wide enough? Certainly we can't have 40-lane freeways in keeping with whatever the relevant required population would be.

Here in Seattle, it's basically been determined that most freeways have "enough" lanes (thanks especially to our very hilly, watery, and expensive geography), and that other modes of transportation (chiefly, light rail and BRT) need some investment. Most widening projects, therefore, are to add HOV and/or express toll lanes. But of course, "the car" is the primary mode of transport for most people because it's by far the easiest of the bunch. But what if our cities were designed to make walking, cycling, or transit-riding easy? That is certainly the bigger issue here. Urban planners are well aware of how important the car is...most of us drive, after all! But cities should be designed around things other than the car, so that we don't have to justify endless investment in road widening.

[hotdogPi]

Someone in City A rides the train to work, because traffic is miserable. They own a car, but they consider it a waste of time (and money) to drive; they have relatively easy access to the train via a local bus a few blocks from their home. City A officials then widen a portion of road that was an essential part of their commute; they switch back to driving because their commute now takes about 25% less time. Their fuel economy is now higher as well, reducing their fuel usage (cheaper).

City A officials widened this road, with the hope that it would reduce the congestion. Perhaps it will, short term. But that high-speed road is now a very attractive option for people who never used that road, stopped using it previously, or just moved to the area. Basically, the road will (ultimately) end up serving people that don't currently use the road. But what if we just don't widen the road? What if that road was just a permanently crappy option? We could widen the road, but if the population is growing, and we widened the road as a response to that, at what point is the freeway wide enough? Certainly we can't have 40-lane freeways in keeping with whatever the relevant required population would be.

The road will probably still be less congested, even with the extra cars. If it's not, he or she will switch back.

[jeffandnicole]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.

More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

Here's the problem: that street doesn't serve anything else besides your neighborhood and has no cut through.

A lot of times, neighborhoods are surrounded on either side by two major roads. People use the many residential streets that go between the two major roads as a cut over. If one of those roads was expanded to four-lanes, chances are it would generate more traffic as it would be a more appealing route rather than the other 2-lane residential streets.

This is generally what happens. 

Minor roads have seen more traffic than intended because the major roads were too crowded or congested.  When the major road is improved or widened, traffic stops using local side roads and instead utilizes the major road.  There's no induced demand here - the amount of traffic is the same in the region.  There's more traffic on the main road but the side roads see less traffic.

Unfortunately, people have bought into the induced demand theory.  Yet, no one is paying attention to the side roads and sees that there's less traffic there.  The residents are happy there's less traffic on their residential side roads...yet they'll also be the first to complain that the main road has more traffic, WHICH IS HOW IT IS SUPPOSED TO WORK.

I can use an area near me as an example: NJ 42 was a very congested 3 lanes each direction.  When 42 was widened from 3 lanes to 4 lanes, people complained the highway quickly started getting congested again.  However, the overall congestion period was a lot less, and the length of the traffic jam was a lot less.  People in the height of rush hour just focued that there was congestion...ignoring that their trip was still shorter and quicker than before.  People outside of rush hour that had some congestion now saw none at all, fully benefiting from the widened highway.  And on nearby NJ 47, one lane each direction, traffic was noticiably lighter on that road.  Congestion all but disappeared.  Many of those that used 47 previously were using 42, saving a good amount of time. 

And of course anti-road people never would disclose how much better the region's traffic actually was, because they still wanted to spend money on light rail, even though the widened road could handle much more traffic throughout the day and night than their precious rail line ever could.

[webny99]

Extra lanes do generate more traffic in any area that's at least moderately populated. All the wishful thinking and rationalization that it doesn't won't change that fact. You can have your own opinions, but facts are facts.

Here's a fact: I live in a residential neighborhood with one exit, which carries an AADT of approximately 320 cars. It's two lanes; if it was widened to four lanes, there would be no change whatsoever in the average AADT.
More lanes only increases traffic when the demand was already growing due to other factors, such as increasing population; demand does not simply appear out of nowhere.

An AADT of 320 shows the area is sparsely populated and likely won't need widening for a very long time. Try again when the population reaches several thousand. Not relevant.

It's plenty densely populated; just doesn't happen to be a very big neighborhood.
It is relevant because it proves that extra lanes don't magically add traffic. If there was an alternate route, maybe traffic would decrease on that route and increase on the other one, but overall traffic would remain unchanged. Increases in population add to traffic woes; increases in capacity alone do not.

[webny99]

But what if we just don't widen the road? What if that road was just a permanently crappy option? We could widen the road, but if the population is growing, and we widened the road as a response to that, at what point is the freeway wide enough? Certainly we can't have 40-lane freeways in keeping with whatever the relevant required population would be.

My opinion is that widening should occur in step with population growth, until land constraints and acquisition costs make further widening impractical. At that point, high rates of growth are no longer sustainable. Investment in other modes of transport can help, but ultimately, the growth needs to slow down/stop entirely or conditions are just going to keep getting worse and worse.

[thspfc]

My opinion is that widening should occur in step with population growth, until land constraints and acquisition costs make further widening impractical. At that point, high rates of growth are no longer sustainable. Investment in other modes of transport can help, but ultimately, the growth needs to slow down/stop entirely or conditions are just going to keep getting worse and worse.

Exhibit A: Atlanta.