Extremely Wide Medians:

[In_Correct]

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.

[epzik8]

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

[kphoger]

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

[capt.ron]

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.. )

[AlexandriaVA]

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

[theline]

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.

[CtrlAltDel]

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.

[Rothman]

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.

[jakeroot]

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





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):

[jakeroot]

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.

[plain]

https://goo.gl/maps/g3hdJqV7wCK2

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


       

[brycecordry]

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.

[jeffe]

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):




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:




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




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

[plain]

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):




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:




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




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

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

[jeffandnicole]

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

[jp the roadgeek]

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

[J N Winkler]

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.

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.

[roadman]

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?

[J N Winkler]

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?

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.

[doorknob60]

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.


I-84 east of Pendleton, OR

[vdeane]

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:



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

[Chris19001]

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

[PHLBOS]

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 features a wide median as well.  Up to a 1/4 mile separation just southeast of the MA 109 (Exit 16A/B) interchange.

[JMAN_WiS&S]

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).

[Truvelo]

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