AARoads Forum

Watching Big Rig Travels, I notice that any mountain land in the east, and just about anything in the West, in the U.S.A., goes crazy when building dual carriage ways. At first, these roads are only a single carriage way with oncoming traffic or two way traffic. Then they add lanes called "Super 2" lanes. When fully upgraded, this carriageway is now a 3 laned with shoulders and the extra lane appears to be useful for trucks that struggle to climb hills.

But when they add the second carriageway, they have an extremely width between the two carriageways. This includes interesting things such as trees, rocks, and even mountains between the two carriage ways. Some times they build the second carriage way at a completely different elevation. It is sometimes higher than the original road, and sometimes it is lower than the original road. I imagine that it was very easy for them to build Interstate Highways in these areas because it looks like the land isn't even used. And now as a result, there is a huge median with plenty of nature between the two carriage ways, that I would think be preserved for ever. I actually prefer this extreme median, but at the same time I also prefer a Concrete Wall between the two carriage ways if the extreme median is not possible. Sometimes have a concrete barriers in the mountain areas. They often have concrete barriers in narrow areas (Gainesville, Texas) and in urban areas and is usually pointless to have medians because they are going to remove them and replace them with concrete barriers and sometimes additional lanes.

When I build cities with SimCity 2000, The roads in SimCity 2000 are always striped with white dotted lines but the only way to add boulevards is to add trees in between the two carriageways. (or small parks, which ends up looking like a grass median). The only way to grade separate rail is to build a "Subway To Rail Connection" going under the carriageways. Otherwise there is a constant elevated 4 lane highway option which goes over everything and has concrete barriers in the middle. I like to add frontage roads next to these. SimCity 3000 has the same highway but is now normally enclosed with walls and has much longer ramps. The regular roads are now striped with dual gold or yellow solid lines and this time you can place two of said roads next to each other and it will become a Boulevard (called Avenue) with trees in the middle. However, the carriageways do not change to a white dotted line or even yellow dotted line. They remain solid yellow and the visible traffic will drive in both directions on both carriageways, basically two two laned two way traffic roads next to each other with trees in the middle. Sim City 4 has improved boulevards and rail and grade separations.

There are other newly built highways such as U.S. 35 that have an "average" width. They do not have wide medians and if they decide to add lanes to it, they will most likely just build the lanes on the median and add a barrier or guard rail in between the carriage ways. Texas has been building carriageways with wide medians that eventually become frontage roads. There is plenty of room to build main carriage ways WITH another median. But if a city in mountain areas (or otherwise very open areas where they have giant medians), they will most likely keep the entire median and have to build frontage roads outside of the existing carriage ways.

I guess I don't understand the point of having medians when they are going to remove them anyways but it would be interesting if they build highways with 3 lane frontage road, 5 lane carriage way, huge median with forest in it, 5 lane carriage way, and 3 lane frontage road. Basically a combination of North Carolina (?) Interstates with Texas Interstates.

Dude, I still love playing SimCity 2000 too! And maybe the removal of medians isn't in the original plans or something.

I voted "All of them" because variety makes driving more interesting.

A lot of the interstates built from the late 1960's onward seemed to feature super wide medians at times... I-40 and I-30 in Arkansas being good examples.
Some interstates that were converted from 4 lane divided highways, for example I-40 in New Mexico between Tucumcari and Santa Rosa, have narrow (and dangerous) medians. (apologies for going off topic a bit.. ) :)

In the Northeastern US you often don't have any spare room to widen a median, so you get a lot of stuff like this:

https://www.google.com/maps/@38.8259664,-77.1218236,3a,75y,82.1h,86.47t/data=!3m7!1e1!3m5!1svXz7qD3bC2Ie09MitQUUGA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DvXz7qD3bC2Ie09MitQUUGA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D321.2032%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

When I was young I was impressed with the very wide median along parts of the New York State Thruway, between Buffalo and the PA line.

Quote from: AlexandriaVA on November 25, 2016, 02:39:55 PM
In the Northeastern US you often don't have any spare room to widen a median, so you get a lot of stuff like this:

https://www.google.com/maps/@38.8259664,-77.1218236,3a,75y,82.1h,86.47t/data=!3m7!1e1!3m5!1svXz7qD3bC2Ie09MitQUUGA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DvXz7qD3bC2Ie09MitQUUGA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D321.2032%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I really think there should be a concrete barrier there, at least between opposing traffic.

Quote from: CtrlAltDel on November 29, 2016, 02:46:18 PM

Quote from: AlexandriaVA on November 25, 2016, 02:39:55 PM
In the Northeastern US you often don't have any spare room to widen a median, so you get a lot of stuff like this:

https://www.google.com/maps/@38.8259664,-77.1218236,3a,75y,82.1h,86.47t/data=!3m7!1e1!3m5!1svXz7qD3bC2Ie09MitQUUGA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DvXz7qD3bC2Ie09MitQUUGA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D321.2032%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

I really think there should be a concrete barrier there, at least between opposing traffic.

Sissy.

I prefer narrow ROWs for freeways. In terms of medians, a concrete step barrier is pretty much how I'd do it:

(https://upload.wikimedia.org/wikipedia/commons/5/53/Concrete_step_barrier_3D_cross_section.jpg)

(https://upload.wikimedia.org/wikipedia/commons/9/94/Concrete_step_barrier_M18_2.JPG?1480462868082)

As for non-freeway roads, BC's approach is my preference. A lane and a half wide median that narrows at intersections, but while maintaining at least a couple of feet of width even at signals. This way, you can put pole-mounted, eye-level signals in the median (which I like):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FwU16Ptx.png&hash=ea0017e297dee2884740c1d439bc2a261a63e3cb)

Opposite above (hence the separate post), I think exceptionally-wide medians, like Pena Blvd (Denver's airport freeway -- below) are just silly. A solid concrete barrier with a little bit of room for error is all you need.

For whatever it's worth, I don't like inside shoulders. I think it promotes stopping in the central reservation. Doing so can make it harder for emergency vehicles to get to your location. Exceptions to that being freeways with HOV/express lanes.

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FXzHYfDt.png&hash=6c1e6506a35a4b00d7372e23f2eadabdbecde107)

https://goo.gl/maps/g3hdJqV7wCK2

I think the West Virginia Turnpike south of Beckley might have the widest median there is


       

When or if I-70 gets redone across Missouri, I vote for them to widen into the median, then put a concrete barrier in between. It WILL fit, although MoDOT says that it will not (since the inside shoulder would be narrower than standard). This will allow them to reuse the existing overpasses, especially those that were replaced six or seven years ago atop the existing piers.

Quote from: plain on November 29, 2016, 07:26:31 PM
I think the West Virginia Turnpike south of Beckley might have the widest median there is       

The median on I-77 at that point is quite wide.  Looks like it is almost ~1300 ft (400m):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FA4mi8Wi.png&hash=1fa4f8787d6b8190dff5edf47c9fdff34d9452b9)


That got me thinking.  I know the median on I-5 north of Los Angeles is also really wide.  The traffic lanes are flipped at this point with the northbound traffic on the left and the southbound traffic on the right due to the reuse of the old US-99 alignment. 

It looks like the median is ~1850 ft (564m) at this point:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F2YCPyZ6.png&hash=9af284cd26c9bdfb9c951c0afafd5ad97a549285)


But the widest median I know of is on I-15 outside of Los Angeles, at 2740 ft (835m):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fso3YW84.png&hash=f901f9a947ada64350e60bbf1d5d28b4f0c23e27)


In this photo you can how wide the median is from Google Streetview:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F9mJmlzT.jpg&hash=9fca09976fb571661232a49ecd745ce065d49362)

Quote from: jeffe on November 30, 2016, 02:54:19 AM

Quote from: plain on November 29, 2016, 07:26:31 PM
I think the West Virginia Turnpike south of Beckley might have the widest median there is       

The median on I-77 at that point is quite wide.  Looks like it is almost ~1300 ft (400m):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FA4mi8Wi.png&hash=1fa4f8787d6b8190dff5edf47c9fdff34d9452b9)


That got me thinking.  I know the median on I-5 north of Los Angeles is also really wide.  The traffic lanes are flipped at this point with the northbound traffic on the left and the southbound traffic on the right due to the reuse of the old US-99 alignment. 

It looks like the median is ~1850 ft (564m) at this point:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F2YCPyZ6.png&hash=9af284cd26c9bdfb9c951c0afafd5ad97a549285)


But the widest median I know of is on I-15 outside of Los Angeles, at 2740 ft (835m):

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fso3YW84.png&hash=f901f9a947ada64350e60bbf1d5d28b4f0c23e27)


In this photo you can how wide the median is from Google Streetview:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F9mJmlzT.jpg&hash=9fca09976fb571661232a49ecd745ce065d49362)

Woah... yes indeed that's wide!! Also last night in another thread someone posted about I-24 northwest of Chattanooga. I'm curious to know how wide that is as well. It looks like the carriageways split to go on each side of a mountain

Quote from: jakeroot on November 29, 2016, 06:54:11 PM
Opposite above (hence the separate post), I think exceptionally-wide medians, like Pena Blvd (Denver's airport freeway -- below) are just silly. A solid concrete barrier with a little bit of room for error is all you need.

For whatever it's worth, I don't like inside shoulders. I think it promotes stopping in the central reservation. Doing so can make it harder for emergency vehicles to get to your location. Exceptions to that being freeways with HOV/express lanes.

The benefit though is if a vehicle in the left lane brakes down, they only have to merge over to the left shoulder to get out of traffic, rather than trying to cross 2 lanes of live traffic.   The left shoulder tends to be preferred by emergency equipment as well.  And when there's an incident on the opposite side of the highway, the left shoulder can be used by emergency responders rather than going up to the next U-turn or exit.

In terms of wide medians...

This spot on the Garden State Parkway in NJ is about 1,000 feet wide: https://goo.gl/maps/jn5mJ29Ga9H2

And while I never thought about it in this way, 295 has a very wide median between the North & South highways at one point...over 1,700 feet! https://goo.gl/maps/ix11yWQRgxy

I-84 in Sturbridge, MA near exit 1 is a little over 1200 feet between carriageways.  The western carriageway was part of the Super 2 Wilbur Cross highway, and the eastern carriageway was added later with the expansion of the road into I-84 (which became I-86 before returning to I-84).

https://goo.gl/maps/pPgVXHvM9n22

Quote from: jakeroot on November 29, 2016, 06:54:11 PMOpposite above (hence the separate post), I think exceptionally-wide medians, like Pena Blvd (Denver's airport freeway -- below) are just silly. A solid concrete barrier with a little bit of room for error is all you need.

For whatever it's worth, I don't like inside shoulders. I think it promotes stopping in the central reservation. Doing so can make it harder for emergency vehicles to get to your location. Exceptions to that being freeways with HOV/express lanes.

From the standpoint of injury risk, it is better to have an errant vehicle come to rest without hitting anything than for it to be intercepted by a barrier.  Medians of 60 feet or more essentially remove the economic case for even low-cost cable barrier.  Wide medians also greatly mitigate headlamp glare and afford more flexibility in handling drainage.

In the early 1960's, when large-scale motorway construction was just getting under way, the British investigated the possibility of providing vegetated medians but found that, owing to the high cost of land even in rural areas, this was nearly as expensive as providing an added lane in each direction.

Interstate standards call for 12 ft shoulders on both sides for facilities that handle heavy truck traffic, as opposed to the default 4 ft left/10 ft right.  One reason for this is added room to respond when trucks have to make emergency maneuvers.

Correct me if I'm wrong, but in the early days of highway construction, weren't the principal reasons for constructing wide medians a) to take advantage of natural terrain, thus reducing construction costs and b) to facilitate future widening of the road without having to acquire additional ROW?

Quote from: roadman on November 30, 2016, 12:10:25 PMCorrect me if I'm wrong, but in the early days of highway construction, weren't the principal reasons for constructing wide medians a) to take advantage of natural terrain, thus reducing construction costs and b) to facilitate future widening of the road without having to acquire additional ROW?

Those are some of the reasons that were operative, but in most states with cheap rural land, there was a progression from building roads with no or vestigial medians to building with much wider medians on right-of-way more than wide enough to accommodate widening on either side of each carriageway.  Right-of-way widths of 300 ft and 400 ft were already quite common by the early 1960's--in contrast, an ordinary Interstate with four lanes (two in each direction) requires just 78 ft plus the chosen median width, and each allowance for an additional lane in each direction adds just 24 ft to the width requirement, with an additional 4 ft one-time for an upgrade to truck shoulders.

It was essentially a tradeoff between one-time and accumulating costs.  Initial purchase of the right-of-way is a one-time cost.  In contrast, crossover accidents and nighttime headlamp glare are recurring costs, as are the maintenance and safety-related costs associated with fixed barriers, light screens, etc. where these are provided as mitigation.  Safety barrier design and economics, as well as glare screens, median landscaping, etc. were very active areas of research in the early 1960's, but they were also fixes to problems that state highway agencies were better off sidestepping altogether in favor of a zero-compromises design if land values would allow them to do so.

Due to the odd curves here, it was hard for me to decide the "right way" to measure this median distance, but regardless of semantics, this is the largest median I can think of.

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FU4Rcu2U.jpg&hash=4128c389c7ea5e96d48ef22f0e2acfb0e06ef6aa)
I-84 east of Pendleton, OR

I've always had a soft spot for the guiderail medians that are used on some roads in NY, including older parts of I-590, I-490, and NY 17:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.nysroads.com%2Fimages%2Fgallery%2FNY%2Fi86%2F100_7786-s.JPG&hash=fde2ce7ba503288040dd4dbd89725e7da32d0ba9)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.nysroads.com%2Fimages%2Fgallery%2FNY%2Fi590%2F100_2688-s.JPG&hash=5cd94a7c2f9bdff0dbf0827ae63a77f6f6219c8a)

As for "widest I can think of", well, this one is pretty wide: https://www.google.com/maps/@32.56539,-115.979145,14z

Here's a previous thread on the subject for what it's worth.  There are some wide ones out there..
https://www.aaroads.com/forum/index.php?topic=13821.0 (https://www.aaroads.com/forum/index.php?topic=13821.0)

Quote from: jp the roadgeek on November 30, 2016, 10:57:01 AM
I-84 in Sturbridge, MA near exit 1 is a little over 1200 feet between carriageways.  The western carriageway was part of the Super 2 Wilbur Cross highway, and the eastern carriageway was added later with the expansion of the road into I-84 (which became I-86 before returning to I-84).

https://goo.gl/maps/pPgVXHvM9n22

This stretch of I-95/MA 128 between Dedham & Needham (https://www.google.com/maps/@42.2462758,-71.1956681,14.24z) features a wide median as well.  Up to a 1/4 mile separation just southeast of the MA 109 (Exit 16A/B) interchange.

I think the width of one carriageway between the two is sufficient, the wider the carriageway, the wider the median. Lately wisdot has started mounting signage in the medians (maybe on us 53 in Eau claire just because of narrow easements).

This one is probably the widest of all at 3 miles.

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.speedcam.uk%2Fd70%2Fwide.jpg&hash=8684c41535152bc10ad5ade023b30dd6051f6238)

For a local suburban arterial I would have to say NJ 23 in Newfoundland, NJ.  At La Rue Road the two carriageways deviate where there is even two separate traffic signals for both sides of Route 23. Though typical for interstates, not really for local highways in a non rural environment and especially NJ as its probably the widest for a NJ non freeway highway.

In fact the La Rue Road intersection could be used in an argument against jughandles in that state due to the fact that unobstructed left turns can be made there, the jughandle there at that location is useless.

New Brunswick, Newfoundland... does NJ have a thing for naming towns after Canadian provinces?

Quote from: roadman65 on December 06, 2016, 09:34:20 AM
For a local suburban arterial I would have to say NJ 23 in Newfoundland, NJ.  At La Rue Road the two carriageways deviate where there is even two separate traffic signals for both sides of Route 23. Though typical for interstates, not really for local highways in a non rural environment and especially NJ as its probably the widest for a NJ non freeway highway.

In fact the La Rue Road intersection could be used in an argument against jughandles in that state due to the fact that unobstructed left turns can be made there, the jughandle there at that location is useless.

Makes me wonder about 9 de Julio Avenue in Buenos Aires.  I thought it had one big median at one point in time, rather than just being 14+ lanes of pavement.

Quote from: doorknob60 on November 30, 2016, 12:50:57 PM
Due to the odd curves here, it was hard for me to decide the "right way" to measure this median distance, but regardless of semantics, this is the largest median I can think of.

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FU4Rcu2U.jpg&hash=4128c389c7ea5e96d48ef22f0e2acfb0e06ef6aa)
I-84 east of Pendleton, OR

How do they determine the center line and center line mileage in cases like this?

Quote from: CtrlAltDel on December 06, 2016, 03:22:16 PM
How do they determine the center line and center line mileage in cases like this?

In many construction plans that I've seen, there is a construction stationing line for the overall facility ("center line", which isn't always in the center) and also a separate station line for each carriageway/ramp/etc.

Per MUTCD, the mileage measurement on a divided highway is to be made along the northbound or eastbound carriageway (i.e. direction of increasing mileposts), with the reference location signs for the opposite direction being placed directly opposite the official one. Some jurisdiction's route logs/center line diagrams catalog divided highways by keeping the overall route official mileage cataloged on the north/east side while using separate reference logging for the non-cardinal/secondary direction.

In New York we use the MUTCD method.  In fact, many of our GIS shapefiles don't even HAVE the secondary direction!

Quote from: vdeane on December 11, 2016, 06:39:30 PM
In New York we use the MUTCD method.  In fact, many of our GIS shapefiles don't even HAVE the secondary direction!

I thought Data Services was doing a lot of work getting reverse direction into their datasets now.

They are; just not sure when they're planning to release it.  The 2015 Traffic Data Viewer doesn't have it, in any case (neither do the current shapefiles for RIS, which also don't yet have the local roads in them).

Quote from: J N Winkler on November 30, 2016, 12:40:04 PMIt was essentially a tradeoff between one-time and accumulating costs.  Initial purchase of the right-of-way is a one-time cost.  In contrast, crossover accidents and nighttime headlamp glare are recurring costs, as are the maintenance and safety-related costs associated with fixed barriers, light screens, etc. where these are provided as mitigation.  Safety barrier design and economics, as well as glare screens, median landscaping, etc. were very active areas of research in the early 1960's, but they were also fixes to problems that state highway agencies were better off sidestepping altogether in favor of a zero-compromises design if land values would allow them to do so.

So, did the decision to go with a 100 foot median rather than 60 come out of a spreadsheet? If so, why didn't every state with low land costs do it? If not, did the Feds generally rubber stamp the extra right of way costs, or was there some pro-rata arrangement with the states?

(I'll be very impressed if anyone can answer these questions!)

Quote from: roadfro on December 11, 2016, 06:30:01 PM

Quote from: CtrlAltDel on December 06, 2016, 03:22:16 PM
How do they determine the center line and center line mileage in cases like this?

Per MUTCD, the mileage measurement on a divided highway is to be made along the northbound or eastbound carriageway (i.e. direction of increasing mileposts), with the reference location signs for the opposite direction being placed directly opposite the official one. Some jurisdiction's route logs/center line diagrams catalog divided highways by keeping the overall route official mileage cataloged on the north/east side while using separate reference logging for the non-cardinal/secondary direction.

That's very interesting, thank you. Do you know which section of the MUTCD discusses this?

Quote from: CtrlAltDel on December 13, 2016, 11:14:47 PM

Quote from: roadfro on December 11, 2016, 06:30:01 PM

Quote from: CtrlAltDel on December 06, 2016, 03:22:16 PM
How do they determine the center line and center line mileage in cases like this?

Per MUTCD, the mileage measurement on a divided highway is to be made along the northbound or eastbound carriageway (i.e. direction of increasing mileposts), with the reference location signs for the opposite direction being placed directly opposite the official one. Some jurisdiction's route logs/center line diagrams catalog divided highways by keeping the overall route official mileage cataloged on the north/east side while using separate reference logging for the non-cardinal/secondary direction.

That's very interesting, thank you. Do you know which section of the MUTCD discusses this?

Section 2H.05 - Reference Location Signs and Intermediate Reference Location Signs (see Standard statement at paragraph 12)

I would think the widest median would be I-5 North of Los Angles, since traffic directions are flipped, the measurement would have to go across the entire world

SM-N915T

Quote from: theline on November 28, 2016, 06:00:13 PM
When I was young I was impressed with the very wide median along parts of the New York State Thruway, between Buffalo and the PA line.

That's primarily a WNY thing?

Didn't know that. I thought it was prevalent throughout the country. I know when you get to the PA line it narrows a lot though.

https://www.google.com/maps/place/37°42'17.2%22N+81°08'40.0%22W/@50.4572075,-106.8781371,13552m/data=!3m1!1e3!4m5!3m4!1s0x0:0x0!8m2!3d37.704769!4d-81.144433?hl=en

Highway 1 near Ernfold, SK.

At its widest point it is almost three miles wide.

Quote from: TheStretchofFreeways on December 24, 2016, 08:45:25 PM
I would think the widest median would be I-5 North of Los Angles, since traffic directions are flipped, the measurement would have to go across the entire world

need a narrower wrong-way median than the mile that that gets to. eg, if this median was something more than two metal rods on the surface (one in the 'in' carriageway) (https://www.google.co.uk/maps/@51.5106021,-0.1210545,3a,30y,151.72h,83.07t/data=!3m6!1e1!3m4!1sEMn0KqfL3dQoQqdqXEEPyA!2e0!7i13312!8i6656) then it would be 39,999,999.5m, rather than 39,998,400m that I-5 in that pass is.

Quote from: Buffaboy on December 27, 2016, 01:23:20 AM

Quote from: theline on November 28, 2016, 06:00:13 PM
When I was young I was impressed with the very wide median along parts of the New York State Thruway, between Buffalo and the PA line.

That's primarily a WNY thing?

Didn't know that. I thought it was prevalent throughout the country. I know when you get to the PA line it narrows a lot though.

You have to understand my perspective. When I was young, so were freeways (early Sixties). Since there weren't that many of them, the Thruway median in western NY was wider than most. It comes nowhere near others that have been cited in this thread. I remember getting out the Kodak 8 mm movie camera and shooting some footage of the wide median. I got into a little trouble with Dad later. He couldn't understand wasting film on that.

Quote from: theline on December 28, 2016, 01:50:25 PM

Quote from: Buffaboy on December 27, 2016, 01:23:20 AM

Quote from: theline on November 28, 2016, 06:00:13 PM
When I was young I was impressed with the very wide median along parts of the New York State Thruway, between Buffalo and the PA line.

That's primarily a WNY thing?

Didn't know that. I thought it was prevalent throughout the country. I know when you get to the PA line it narrows a lot though.

You have to understand my perspective. When I was young, so were freeways (early Sixties). Since there weren't that many of them, the Thruway median in western NY was wider than most. It comes nowhere near others that have been cited in this thread. I remember getting out the Kodak 8 mm movie camera and shooting some footage of the wide median. I got into a little trouble with Dad later. He couldn't understand wasting film on that.

I'm 45 years younger but when I was around the same age I used my Dad's Sony Handycam for the same thing  :-D.

I can see how the medians were narrower thought the country. Maybe it had something to do with keeping the construction vehicles closer together, or RoW.

Quote from: jeffe on November 30, 2016, 02:54:19 AM

That got me thinking.  I know the median on I-5 north of Los Angeles is also really wide.  The traffic lanes are flipped at this point with the northbound traffic on the left and the southbound traffic on the right due to the reuse of the old US-99 alignment. 

Does anyone have an explanation for why they flipped the lanes at this point?  Is it a downgrade issue?  Is the grade on the western lanes (which were converted from the old highway) steeper than in the new(er) eastern lanes?

Quote from: english si on December 27, 2016, 04:26:58 PM

Quote from: TheStretchofFreeways on December 24, 2016, 08:45:25 PM
I would think the widest median would be I-5 North of Los Angles, since traffic directions are flipped, the measurement would have to go across the entire world

need a narrower wrong-way median than the mile that that gets to. eg, if this median was something more than two metal rods on the surface (one in the 'in' carriageway) (https://www.google.co.uk/maps/@51.5106021,-0.1210545,3a,30y,151.72h,83.07t/data=!3m6!1e1!3m4!1sEMn0KqfL3dQoQqdqXEEPyA!2e0!7i13312!8i6656) then it would be 39,999,999.5m, rather than 39,998,400m that I-5 in that pass is.

If you are talking about wrong way roads in the UK, That most probably won't count since it is normal for traffic to be on the left side of the carriageway

Quote from: TheStretchofFreeways on December 30, 2016, 10:49:00 PM

Quote from: english si on December 27, 2016, 04:26:58 PM

Quote from: TheStretchofFreeways on December 24, 2016, 08:45:25 PM
I would think the widest median would be I-5 North of Los Angles, since traffic directions are flipped, the measurement would have to go across the entire world

need a narrower wrong-way median than the mile that that gets to. eg, if this median was something more than two metal rods on the surface (one in the 'in' carriageway) (https://www.google.co.uk/maps/@51.5106021,-0.1210545,3a,30y,151.72h,83.07t/data=!3m6!1e1!3m4!1sEMn0KqfL3dQoQqdqXEEPyA!2e0!7i13312!8i6656) then it would be 39,999,999.5m, rather than 39,998,400m that I-5 in that pass is.

If you are talking about wrong way roads in the UK, That most probably won't count since it is normal for traffic to be on the left side of the carriageway

The link goes to a GSV where traffic flows on the right.  In London.

How about this one, english si?  Narrow raised median in Mexico, traffic driving on the left. (https://goo.gl/maps/homjzvVDa4r)

Phoenix's Sky Harbor Airport has left-hand traffic along the main boulevard. Much wider than the Mexican and British examples above, but much narrower than the Castaic example.

https://goo.gl/Wd75SC

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fw41INZw.png&hash=d06c8f31321b3c7a1152adbb4ddb531e55920ba4)

I-24 West of Chattanooga has a fairly wide median:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimgur.com%2Fzn2oU6N.jpg&hash=cd605fa1a75ed65b100c9467f2064a331fbe3aba)

Quote from: jbnati27 on January 05, 2017, 11:05:08 AM
I-24 West of Chattanooga has a fairly wide median:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimgur.com%2Fzn2oU6N.jpg&hash=cd605fa1a75ed65b100c9467f2064a331fbe3aba)

Yes indeed. There is an even larger median going down the Cumberland Plateau.

I now know I am wrong, but when I was younger I actually thought the Interstate 24 median going down the Cumberland Plateau was the widest one ever. And since I genuinely believed it, in one of my road videos on my YouTube channel (I-24 East up-then-down the Cumberland Plateau) I actually added an annotation of what I thought was a fact, saying that it was the widest median. Oh well, I should probably fix that when I get a chance.


Also, I voted "all of them" on the poll, because as someone said earlier in the thread, a variety is good.

Quote from: jakeroot on December 31, 2016, 02:37:07 AM
Phoenix's Sky Harbor Airport has left-hand traffic along the main boulevard. Much wider than the Mexican and British examples above, but much narrower than the Castaic example.

https://goo.gl/Wd75SC

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fw41INZw.png&hash=d06c8f31321b3c7a1152adbb4ddb531e55920ba4)

I'm old enough to remember when it used to be configured for right side traffic.  They reversed it to eliminate some intersections and left turns.

Quote from: kphoger on December 30, 2016, 10:56:27 PM

Quote from: TheStretchofFreeways on December 30, 2016, 10:49:00 PM

Quote from: english si on December 27, 2016, 04:26:58 PM

Quote from: TheStretchofFreeways on December 24, 2016, 08:45:25 PM
I would think the widest median would be I-5 North of Los Angles, since traffic directions are flipped, the measurement would have to go across the entire world

need a narrower wrong-way median than the mile that that gets to. eg, if this median was something more than two metal rods on the surface (one in the 'in' carriageway) (https://www.google.co.uk/maps/@51.5106021,-0.1210545,3a,30y,151.72h,83.07t/data=!3m6!1e1!3m4!1sEMn0KqfL3dQoQqdqXEEPyA!2e0!7i13312!8i6656) then it would be 39,999,999.5m, rather than 39,998,400m that I-5 in that pass is.

If you are talking about wrong way roads in the UK, That most probably won't count since it is normal for traffic to be on the left side of the carriageway

The link goes to a GSV where traffic flows on the right.  In London.

How about this one, english si?  Narrow raised median in Mexico, traffic driving on the left. (https://goo.gl/maps/homjzvVDa4r)

The one in mexico would count since their traffic is also supposed to be in the right

SM-N915T

Quote from: J N Winkler on November 30, 2016, 12:00:25 PM

Quote from: jakeroot on November 29, 2016, 06:54:11 PMOpposite above (hence the separate post), I think exceptionally-wide medians, like Pena Blvd (Denver's airport freeway -- below) are just silly. A solid concrete barrier with a little bit of room for error is all you need.

For whatever it's worth, I don't like inside shoulders. I think it promotes stopping in the central reservation. Doing so can make it harder for emergency vehicles to get to your location. Exceptions to that being freeways with HOV/express lanes.

From the standpoint of injury risk, it is better to have an errant vehicle come to rest without hitting anything than for it to be intercepted by a barrier.  Medians of 60 feet or more essentially remove the economic case for even low-cost cable barrier.  Wide medians also greatly mitigate headlamp glare and afford more flexibility in handling drainage.

In the early 1960's, when large-scale motorway construction was just getting under way, the British investigated the possibility of providing vegetated medians but found that, owing to the high cost of land even in rural areas, this was nearly as expensive as providing an added lane in each direction.

Interstate standards call for 12 ft shoulders on both sides for facilities that handle heavy truck traffic, as opposed to the default 4 ft left/10 ft right.  One reason for this is added room to respond when trucks have to make emergency maneuvers.

Someone should have schooled Pete Rahn and Gary Johnson on that - in the mid to late nineties.  They approved two four lane projects - NM 44/US 550 and US 70, both of which had simply painted medians of roughly 3 or 4 feet.  Speeds increased, as well as head-ons and Jack-knives, and the resulting death toll from them.  There was another wreck in Cuba, NM (44/550) the other day, a freightliner crossed the center line, and impacted an SUV carrying four occupants.   All the SUV passengers, dead, as well as the driver of the Freightliner.  The Freightliner driver was drunk.  A vegetated median, of the standard 88 feet, or greater, would have likely captured the Freightliner from crossing into oncoming traffic.   Can a state DOT be sued - for poor design, in a case such as this??   

The I-55/I-44 ramps to/from Lafayette Ave in St Louis have a pretty tight median for a short stretch: https://goo.gl/iAMOSz

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FYK72RZU.png&hash=70278dd67121086bd516ff8c944100f2d4b7d0d2)

These are normal around these parts, Here's some examples. 
https://www.google.com/maps/@39.6708394,-75.598977,3a,66.8y,9.47h,82.65t/data=!3m4!1e1!3m2!1sjdsanxQw74OqQCu2QzpT_A!2e0

https://www.google.com/maps/@39.5812631,-75.658203,3a,66.8y,9.47h,82.65t/data=!3m4!1e1!3m2!1s0k3AyFhScfLaUIqx8UDo1g!2e0

https://www.google.com/maps/@39.4975871,-75.6458275,3a,92y,219.74h,71.64t/data=!3m4!1e1!3m2!1s_D3-BTG3T_jrY2ApurAklQ!2e0

https://www.google.com/maps/@34.8060268,-111.6136552,14.25z

Sections of I-17 sport fairly wide medians.

One not mentioned yet, I-75 in Reading-Lockland Ohio. there is a town in the median of I-75 near Cincinnati and the NB lanes was relocated in the early 60s resulting in the wide median.

Quote from: In_Correct on November 19, 2016, 03:47:40 AM
Watching Big Rig Travels, I notice that any mountain land in the east, and just about anything in the West, in the U.S.A., goes crazy when building dual carriage ways. At first, these roads are only a single carriage way with oncoming traffic or two way traffic. Then they add lanes called "Super 2" lanes. When fully upgraded, this carriageway is now a 3 laned with shoulders and the extra lane appears to be useful for trucks that struggle to climb hills.

But when they add the second carriageway, they have an extremely width between the two carriageways. This includes interesting things such as trees, rocks, and even mountains between the two carriage ways. Some times they build the second carriage way at a completely different elevation. It is sometimes higher than the original road, and sometimes it is lower than the original road. I imagine that it was very easy for them to build Interstate Highways in these areas because it looks like the land isn't even used. And now as a result, there is a huge median with plenty of nature between the two carriage ways, that I would think be preserved for ever. I actually prefer this extreme median, but at the same time I also prefer a Concrete Wall between the two carriage ways if the extreme median is not possible. Sometimes have a concrete barriers in the mountain areas. They often have concrete barriers in narrow areas (Gainesville, Texas) and in urban areas and is usually pointless to have medians because they are going to remove them and replace them with concrete barriers and sometimes additional lanes.

When I build cities with SimCity 2000, The roads in SimCity 2000 are always striped with white dotted lines but the only way to add boulevards is to add trees in between the two carriageways. (or small parks, which ends up looking like a grass median). The only way to grade separate rail is to build a "Subway To Rail Connection" going under the carriageways. Otherwise there is a constant elevated 4 lane highway option which goes over everything and has concrete barriers in the middle. I like to add frontage roads next to these. SimCity 3000 has the same highway but is now normally enclosed with walls and has much longer ramps. The regular roads are now striped with dual gold or yellow solid lines and this time you can place two of said roads next to each other and it will become a Boulevard (called Avenue) with trees in the middle. However, the carriageways do not change to a white dotted line or even yellow dotted line. They remain solid yellow and the visible traffic will drive in both directions on both carriageways, basically two two laned two way traffic roads next to each other with trees in the middle. Sim City 4 has improved boulevards and rail and grade separations.

There are other newly built highways such as U.S. 35 that have an "average" width. They do not have wide medians and if they decide to add lanes to it, they will most likely just build the lanes on the median and add a barrier or guard rail in between the carriage ways. Texas has been building carriageways with wide medians that eventually become frontage roads. There is plenty of room to build main carriage ways WITH another median. But if a city in mountain areas (or otherwise very open areas where they have giant medians), they will most likely keep the entire median and have to build frontage roads outside of the existing carriage ways.

I guess I don't understand the point of having medians when they are going to remove them anyways but it would be interesting if they build highways with 3 lane frontage road, 5 lane carriage way, huge median with forest in it, 5 lane carriage way, and 3 lane frontage road. Basically a combination of North Carolina (?) Interstates with Texas Interstates.

I looked again and SimCity 2000 has 6 lane elevated highways, not 4.

Also, I was able to build a reinforced highway bridge for the first time. The highway bridges are truss bridges while the frontage road bridges are cable stayed. But both are red. So far the rail bridges over water appear to be the same design.

Quote from: DJStephens on May 19, 2017, 03:20:23 PMSomeone should have schooled Pete Rahn and Gary Johnson on that - in the mid to late nineties.  They approved two four lane projects - NM 44/US 550 and US 70, both of which had simply painted medians of roughly 3 or 4 feet.  Speeds increased, as well as head-ons and Jack-knives, and the resulting death toll from them.  There was another wreck in Cuba, NM (44/550) the other day, a freightliner crossed the center line, and impacted an SUV carrying four occupants.   All the SUV passengers, dead, as well as the driver of the Freightliner.  The Freightliner driver was drunk.  A vegetated median, of the standard 88 feet, or greater, would have likely captured the Freightliner from crossing into oncoming traffic.   Can a state DOT be sued - for poor design, in a case such as this??

I remember the NM 44 project ("Four Lanes to the Four Corners") well from the late nineties.  The stated goal was to do in two years, with innovative finance, what would have taken 27 years using what were then the normal programming methods.  The four-lane undivided rural arterial cross-section on top of the existing alignment was sort of handwaved away as a necessary compromise to reach that goal.  Because its width and lane count were simply increased without any upgrades to the geometry, the road has horizontal curves that feel too sharp at 70 MPH as well as numerous blind summits with 65 MPH advisories (NMSHTD used to have, and NMDOT may still have, special symbolic warning signs for these).  I believe these factors, as well as the too-narrow central mall, have contributed to its deplorable safety record.

Later on NMSHTD/NMDOT suddenly "discovered" the capability to widen long lengths of US 87, US 54, US 82, US 285, US 70, etc. to a proper four-lane divided cross-section with a true 70 MPH design speed.

As regards the Hondo Valley segment of US 70, my understanding is that was a compromise to accommodate the narrow valley alignment.  There is an unexpected and very sharp curve where it climbs out of the valley toward Roswell that I think must be a bad accident black spot.

So, no one's mentioned I-24 near Monteagle, TN?

https://goo.gl/maps/FFAVbW9WH7s

1.75 miles wide....

Quote from: MikeTheActuary on May 26, 2017, 10:10:01 AM
So, no one's mentioned I-24 near Monteagle, TN?

https://goo.gl/maps/FFAVbW9WH7s

1.75 miles wide....

I wonder why they didnt just cut thru the mountain instead of making the hard curve, they already dug thru half the moutain.... Finish the rest!  :clap:

Pretty much any highway built in the 70s, you can see all of these.

US-264 between Middlesex and Bailey. It's 1,000 feet (300 meters) wide. Which Turkey Creek passes under. It's a scenic byway.

https://www.google.com/maps/@35.7959385,-78.173617,1210m/data=!3m1!1e3

On I-79 in West Virginia, there's a creek in median almost the entire distance between Wallback (Exit 34) and Big Otter (exit 40).  And it's not all the same creek, as adjacent hollows (pronounced hollers) dump Cookman Fork heading [westbound] and Boggs Fork (heading eastbound) into the median just a quarter mile from each other.  At it's widest, it looks like right at 500 feet between the centerlines of each lane (roughly 450-foot median).

In Montana there are at least 2 instances of rivers being in the median

https://www.google.com/maps/@47.293523,-115.1461587,3a,75y,334.9h,76.81t/data=!3m7!1e1!3m5!1swlypjkPQl2Rlb6RL_emT5g!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DwlypjkPQl2Rlb6RL_emT5g%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D99.73118%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192 (https://www.google.com/maps/@47.293523,-115.1461587,3a,75y,334.9h,76.81t/data=!3m7!1e1!3m5!1swlypjkPQl2Rlb6RL_emT5g!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DwlypjkPQl2Rlb6RL_emT5g%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D99.73118%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192)

https://www.google.com/maps/@46.2375684,-112.1620777,3a,80.7y,43.27h,73.75t/data=!3m7!1e1!3m5!1syZsnA5qiciqe6LvyvkLSXw!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DyZsnA5qiciqe6LvyvkLSXw%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D346.66858%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192 (https://www.google.com/maps/@46.2375684,-112.1620777,3a,80.7y,43.27h,73.75t/data=!3m7!1e1!3m5!1syZsnA5qiciqe6LvyvkLSXw!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DyZsnA5qiciqe6LvyvkLSXw%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D346.66858%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192)

As well as one house located in the median

https://www.google.com/maps/@45.6628689,-110.6711411,3a,75y,351.45h,85.78t/data=!3m6!1e1!3m4!1swHwNb7ri-VLQ3S1EvC4ihg!2e0!7i16384!8i8192 (https://www.google.com/maps/@45.6628689,-110.6711411,3a,75y,351.45h,85.78t/data=!3m6!1e1!3m4!1swHwNb7ri-VLQ3S1EvC4ihg!2e0!7i16384!8i8192)

These extreme examples aside, wide medians are desirable in most cases, particularly urban, suburban, or exurban areas where they reserve additional space for adding lanes and hopefully service plazas one day. Particularly in suburban and rural areas they also increase the effectiveness of the highway as a barrier (for example, between residential and industrial areas).

This one in New Orleans has an unusually wide median for an urban street: https://www.google.com/maps/@29.8961723,-90.1371321,3a,75y,103.67h,82.22t/data=!3m7!1e1!3m5!1svokVHHIDEghbbL5SMgXjpg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DvokVHHIDEghbbL5SMgXjpg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D346.6732%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

Quote from: thspfc on February 02, 2022, 11:35:23 AM
This one in New Orleans has an unusually wide median for an urban street: https://www.google.com/maps/@29.8961723,-90.1371321,3a,75y,103.67h,82.22t/data=!3m7!1e1!3m5!1svokVHHIDEghbbL5SMgXjpg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DvokVHHIDEghbbL5SMgXjpg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D346.6732%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

Isn't that supposed to become part of I-49?

Also in my thoughts, highways built before 1965 have medians that are too narrow??!!!

Quote from: vdeane on February 02, 2022, 12:40:12 PM

Quote from: thspfc on February 02, 2022, 11:35:23 AM
This one in New Orleans has an unusually wide median for an urban street: https://www.google.com/maps/@29.8961723,-90.1371321,3a,75y,103.67h,82.22t/data=!3m7!1e1!3m5!1svokVHHIDEghbbL5SMgXjpg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DvokVHHIDEghbbL5SMgXjpg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D346.6732%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

Isn't that supposed to become part of I-49?

I believe so.

Even if it wasn't, there's plenty of room to extend the freeway portion of the Westbank if they wanted to. That's actually a great design there; it's basically 2 one-way streets with no development in between them.

Gee, I missed this one on the West Virginia Turnpike.  The split around Beaver Creek southeast of the I-64 interchange is about 1335 feet between centerlines.

One controversial one is Monumental Axis in Brasilia.  Some call it the world's widest road with a 250-meter median, though it acta like 2 separate one-way roads.