Variable Lane Freeways

[Rapmastac1]

I was thinking about this the other day and did a Google search on it. France is trying out a technology that is similar to what I'm thinking of. But they did this a long time ago, and from what see, they have abandoned the use of the technology.

Variable Lane Freeways is a method in which you have a normal 4 Lane freeway (4 lanes in each direction, although it can be as low as 2 lanes in each direction). You have 4 lanes going in each direction and then you have a center lane (emergency lane). The barrier between the lanes is adjustable. Where I live, Salt Lake City is the center of attention for most people. When people go to work, the freeway is clogged up southbound towards SLC and at night is clogged in the northbound direction.

In the morning, southbound will have up to 6 lanes which helps speed the process of getting there. When you have more people traveling on the inside lanes and less on the outside lanes, getting onto the freeway is easier (which is where the weakness is, causing traffic slowdowns). And then at night, the barrier will be moved to the opposite side giving the northbound direction 6 lanes. This is great for countering bad traffic caused by rush hour, construction.

Using this concept along with variable speed limits I'm pretty sure most traffic congesting problems will be solved without having to have 8 lane freeways in each direction. The cost to implement this system in the long run will be about the same as building up to 8 lanes, except without using up more land (which isn't always available).

What do you guys think?

[mkrishnan]

There may not be any giant machines imported from Cybertron to move the barriers, but I'm pretty sure this method, conceptually (albeit with less sophistication), is employed in the US already... I'm struggling with where the specific examples I've seen are, though, so someone may have to help out. I think this is done in the LA area, for one.

Wherever it is that I'm thinking of, the way it's done is that there are a few central express lanes with signage for drivers driving in both directions, but the local/express switch ramps are only open to traffic going in one direction, depending on the time of day (i.e. into the city in the morning and out of the city in the evening).

I'm not sure how to Google for it, or I'd provide more specifics, but I'm sure I've seen this in at least one place in the US....

Now, the political answer... (and yes, I'm moving this to the PRSI, hope that's okay)... Reducing traffic congestion reduces emissions and wasted fuel, but it also encourages more commuter traffic, no? Does France (which already has done more generally to enable alternatives to driving to work) have evidence that this is not a fundamentally ill advised sort of idea, along the lines of "find more, use less?"

[Greedo]

they have this on Rte 93 north going into boston already. works fine in my experience.

[LumbermanSVO]

Seattle has some reversible lanes but they are poorly implemented and IMO don't help as much as they could.

[brax.j]

Seattle has system like this but it is more efficient than the Salt Lake City form. It as two lanes that go through the entire city with minimal exits and entrances so in the morning the lanes are open to people going southbound and in the afternoon they are open to people going northbound. They are very efficient because only people that are going all the way through the city can use the lanes and allows them to move faster and not get clogged by people exiting and entering the freeway.

[mkrishnan]

Seattle has some reversible lanes but they are poorly implemented and IMO don't help as much as they could.

Maybe it is Seattle I'm thinking of (it isn't Boston -- I've never driven in Boston)... I haven't been to Seattle in a while, so it's quite possible.... So they don't help much, eh?

Salt Lake City has in-city / metro trains, right? Does it have a commuter rail? Seems like a commuter rail or one of those trolley-bus / whatever systems that work sort of intermediately between a train and a bus is a much better solution than allowing for an increased density of individual traffic....

[brax.j]

Seattle has some reversible lanes but they are poorly implemented and IMO don't help as much as they could.

They could be better but I disagree they could help more. They are there to help people going through the entire city not people that are getting off in the city.

[LethalWolfe]

There is at least on section of road near down town Indianapolis that is like that. There's no physical barrier to move just overhead lane makers w/either a red X or a green arrow.


Lethal

[Demosthenes X]

Vancouver has variable highways in some places - mostly around the tunnels and bridges, for obvious reasons. It seems to work well (I don't often drive in Vancouver), and certainly helps. But Vancouver still has congestion.

Still, it's a great idea and perfectly logical, so more highway systems should implement it, imo.

[yg17]

St. Louis has a reversible lane on a short stretch of I-70 going through the city. I've used it once, but I'm hardly ever on that part of I-70....and I don't think it does a thing to reduce traffic. The eastern end of the lane ends just before you really get into the heart of downtown and the western end doesn't even get you into the suburbs where a majority of the commuters are going to and from.

[NT1440]

Virginias got them.

[fireshot91]

Yupp. In VA it's called the HOV- High Occupancy Vehicle.

In the middle of the two sides, there's one road- The HOV part. During rush hour, only bikes, and 3ormore people cars can go on it, so it reduces traffic.

During morning time, it's going north, and after about noon, it goes south.
On Saturdays, it's open to any cars, and it depends on which way it's going.

[NT1440]

Yupp. In VA it's called the HOV- High Occupancy Vehicle.

In the middle of the two sides, there's one road- The HOV part. During rush hour, only bikes, and 3ormore people cars can go on it, so it reduces traffic.

During morning time, it's going north, and after about noon, it goes south.
On Saturdays, it's open to any cars, and it depends on which way it's going.

Odd thing was the lane in the center was ALWAYS empty for the 4 days I was in VA.

[Signal-11]

Yeah, this is done for HOV lanes in several US metro areas. In the older east coast cities, there are also reversible city traffic lanes, though I've seen them taken down in heavy pedestrian areas.

I've had it explained to me by traffic engineers why reversible lanes aren't all that cost effective once you start considering cost over time. This is actually a very complicated subject and there's a reason that traffic engineers are guys with civ E degrees with PE licenses.

[MTI]

Honolulu, site of worst commute route in the nation (yes, an island beat you), uses a "Zipper Lane" in the mornings for vehicles with three or more riders. It is opened in the early morning and put back against the median a few hours later.

http://www.hawaiihighways.com/H1-zipmobile.jpg

[xUKHCx]

There are a few of these around the UK, one going into Birmingham from the M6. It uses overhad gantries with signage to show the allowed lanes.

There was also a pilot for allowing the use of the hardshoulder as an extra lane during heavy traffic periods (carefully monitored for breakdowns etc)

[KingYaba]

We need twenty lanes in each direction. :mad:

[Counterfit]

(it isn't Boston -- I've never driven in Boston).

You don't know what you're missing. :D Try it during October, with a Playoff game at Fenway and either the Celtics or Bruins at the "Garden"*.





*: There was, and will only ever be, one Gahden. What's there now will forever be the Fleet Center to me.

[mkrishnan]

*: There was, and will only ever be, one Gahden. What's there now will forever be the Fleet Center to me.

I understand completely, as all the Chicago demis know I still go to Marshall Fields (but only for the one on State St in Chicago... otherwise I'm fine with calling it Macy's... but their other stores are deplorable...and this is a major tangent). ;)

No thanks for driving in Boston. I barely care for driving in the Chi. I love my feet and public transportation, although the latter is fairly useless in Grand Rapids. :rolleyes: (Who is the genius who decides that the airport bus line only runs on weekdays? I mean, WTF?)

[PlaceofDis]

Chicago has Express lanes that are reversible and go east into the city in the morning rush and west out of the city in the afternoon rush. they're in the center lanes and run alongside the EL for part of the way too. they're fairly good at helping ease the congestion, but certainly doesn't work wonders because there is just that much traffic.

[mkrishnan]

Chicago has Express lanes that are reversible and go east into the city in the morning rush and west out of the city in the afternoon rush. they're in the center lanes and run alongside the EL for part of the way too. they're fairly good at helping ease the congestion, but certainly doesn't work wonders because there is just that much traffic.

This shows how much I drive in Chicago. :D Which interstate? I don't think the Dan Ryan ones reverse, do they? Are you talking about where the blue line runs near the E/W interstates?

[PlaceofDis]

This shows how much I drive in Chicago. :D Which interstate? I don't think the Dan Ryan ones reverse, do they? Are you talking about where the blue line runs near the E/W interstates?

its the "Kennedy" or 90/94 from the Edens Junction to Ohio Street running northwest from the city. i doubt you've been on it very much. ;)

[mkrishnan]

its the "Kennedy" or 90/94 from the Edens Junction to Ohio Street running northwest from the city. i doubt you've been on it very much. ;)

Hehe, no, I think Western is as far as I go that way. :D

[sammich]

There's a small section just north of the Sydney Harbour Bridge. There's a long strip 'creeper' that moves after the morning peak to allow more traffic to head north (morning peak heads south to the city).

Just stick these (-33.845036,151.211823) coords into maps.google.com, and streetview it.

[aethelbert]

There is at least on section of road near down town Indianapolis that is like that. There's no physical barrier to move just overhead lane makers w/either a red X or a green arrow.
Seriously? Where is this? I've been around Indianapolis for many, many years and have never seen that. It's certainly not on the interstate and most streets downtown are one way, no? Care to enlighten me for curiosity's sake?

As for the actual topic, I have seen similar methods used during construction on a bridge in Peoria (US 150), but it created many traffic problems and backups when it was time to move the lane divider. It served the purpose well, as without it there would have only been eastbound traffic, but the backups that it caused when moving were incredible as it took forever. As there is no other way across the river for many miles, it hurt the area pretty hard during select parts of the day.

[.Andy]

There's a small section just north of the Sydney Harbour Bridge. There's a long strip 'creeper' that moves after the morning peak to allow more traffic to head north (morning peak heads south to the city).

Just stick these (-33.845036,151.211823) coords into maps.google.com, and streetview it.
Not only that but variable traffic flow lanes have been utilised on the pacific highway up as far as Turramurra since the late 80's/early 90's. It's not a new concept.

However why it's even needed when there's a wonderful public transport system that feeds into sydney along the north shore is beyond me. Single-occupant cars should be tolled twice the rate.

[OutThere]

Seriously? Where is this? I've been around Indianapolis for many, many years and have never seen that. It's certainly not on the interstate and most streets downtown are one way, no? Care to enlighten me for curiosity's sake?


It's Fall Creek Parkway...right near Butler and the Fairgrounds, just for a little ways. Not exactly downtown. It's actually kind of confusing if you're not expecting it/at intersections, I drove on it last summer when visiting relatives in Indy.

edit: google streetview http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=central+ave+and+fall+creek+dr,+indianapolis,+in&sll=39.818953,-86.15118&sspn=0.025249,0.037551&ie=UTF8&ll=39.81503,-86.142941&spn=0.005851,0.018775&z=16&layer=c&cbll=39.815027,-86.142945&panoid=n5gqTsJBZ0-bYS9Rs2Dviw&cbp=12,71.56,,0,0.06

[aethelbert]

It's Fall Creek Parkway...right near Butler and the Fairgrounds, just for a little ways. Not exactly downtown. It's actually kind of confusing if you're not expecting it/at intersections, I drove on it last summer when visiting relatives in Indy.
Ah, yes. I was thinking closer to downtown, but now I remember that. I haven't been on that road in probably five years. Thanks for jogging my memory!

[sammich]

Not only that but variable traffic flow lanes have been utilised on the pacific highway up as far as Turramurra since the late 80's/early 90's. It's not a new concept.

However why it's even needed when there's a wonderful public transport system that feeds into sydney along the north shore is beyond me. Single-occupant cars should be tolled twice the rate.

Well I live in that area, and I'm very familiar with the Turramurra lane switch system (people get hugely confused in these areas because they join dots on the ground and think it's lane markers and they'll switch lanes randomly) but I thought we were more focussed on automatic systems, like the one on the Harbour Bridge. The Turramurra ones are just soft bollards that traffic control have to put down.

[bradl]

Omaha has something similar on the main surface street going through the town.

Dodge Street (US highway 6) is a 5 lane road physically. In the morning rush hour period (7am - 9am), the middle lane is for east bound traffic. Anytime afterwards, the middle lane is for westbound traffic. Until there is a median (after 72nd street), you can't make a left turn anywhere on the street.

Also, there another street (Farnam, IIRC), which is 2 lane. Morning rush (7am - 9am), all lanes are one way, eastbound. Evening rush (4pm - 6pm), all lanes are westbound. Any other time, it's one lane each way.

They've been that way for the past 30something years, and there hasn't been a problem there at all.

BL.

[LumbermanSVO]

They could be better but I disagree they could help more. They are there to help people going through the entire city not people that are getting off in the city.

You could argue that it is there to help people in in/out of the city and not through the city. Three of the four lanes go right into downtown surface streets.

The biggest problem with downtown Seattle itself is the Convention Center built right over I-5. In the morning the Express lanes only have one lane that actually goes through Seattle, and this one lane dumps out into and regular HOV lane on the mainline I-5, in a section that is limited to only two regular lanes and one HOV lane. Brilliant :rolleyes:

In the evening the Express lanes dump into the mainline I-5 in a much better way. The problem is still on the other side of the road though. You have an HOV lane that ends while you have a very busy on-ramp that dumps into an exit only lane, at the same time. The whole southbound side is bottlenecked right there at the Northgate Mall interchange. Even on a Sunday evening it is stop and go there.

If the express lanes went all the way down to Boeing Field and went both directions then they would help people get through the city.

The biggest problems with Seattle traffic is that no one wants to take a regional approach to fixing it and they let every little neighborhood committee stop any project that might, possibly, maybe effect their area.

[neiltc13]

There are no roads with more than 2 lanes within about a 100 mile radius of my house. The closest are in Glasgow, where at some points of the M8 the road becomes 5 lanes wide, but it's not for long and soon the road is back to 2 lanes.

[peskaa]

Birmingham (UK) has been using this on the A38(M) at the M6 interchange (Spaghetti Junction) for as long as I can remember. In the morning there is 5 lanes going into the city, then during the day the middle lane (coloured red) is closed. For the evening peak, it then reverses and there are 5 lanes going out.

It works, has few accidents, and has been in place for many years.