Mainline Interstate exits you cannot use

[bassoon1986]

The past few times I've traveled to Dallas (Arlington to be exact), I've noticed this sign on I-20 westbound beneath the I-635 interchange:
https://www.google.com/maps/@32.7015814,-96.6241303,3a,75y,262.33h,87.08t/data=!3m6!1e1!3m4!1s_SVN0mrLYV0-0ef5I5xHYg!2e0!7i13312!8i6656

I think it's very interesting because you would think that from the mainline, not from an incoming ramp, you should be able to access every exit from the interstate. Excluding of course that some streets are only accessible in one direction on a freeway. Truth be told, this US 175 east exit can be accessed, you just have to cross 3 lanes of incoming I-635 traffic in about 1/8 of a mile, so it isn't totally a case of you can't make the exit. I can't imagine that many travelers on westbound I-20 would want to exit back and nearly make a u-turn to go east on US 175.

This is very likely a remnant when I-20 followed what is now US 80 from Terrell to Dallas. After the time when I-20 followed the DFW Turnpike between the city centers, it turned southbound in Mesquite along the Dallas loop (LBJ Freeway/I-635) which would have made this exit easily accessible. It was only in the last 30 years that the piece of current I-20 was completed between Terrell and Balch Springs. I-635 is really the original through route.

But the sign remains as a command (suggestion?) Any other examples?

[noelbotevera]

Here's the next gantry:
https://www.google.com/maps/@32.6986174,-96.6280578,3a,75y,247.27h,87.08t/data=!3m6!1e1!3m4!1sjSlIXXDDVgOMRiU1h8NhTQ!2e0!7i13312!8i6656

[cl94]

Until the ramp was relocated, this existed in Columbus. While not an Interstate, a similar thing happens on SR 315 a couple miles away.

[KEK Inc.]

Generally, they use pylons or double-white lines in Washington to denote that it's unsafe to jump X-lanes to make an exit. 

[hbelkins]

Similarly, there's an entrance to northbound I-75 in Cincinnati that cannot use I-75. It only offers access to I-74.

[Bruce]

There's two HOV left-hand exits that have extra striping to prevent people from merging all the way across to exit off: at S. Everett Freeway Station (S 112th Street) and SR 526; and at Lynnwood Transit Center (44th Avenue W) and I-405/SR 525 in Lynnwood.

[doorknob60]

I-84 Eastbound in Boise uses a separate ramp wrapping around the I-184 interchange for people wanting to exit at Cole Rd./Overland Rd. to avoid this problem. This is easy because it's a Y interchange, not 4 way so it did not require grade separation, but this is the right way to handle this. https://www.google.com/maps/@43.5929805,-116.2811057,808m/data=!3m1!1e3

This section also has an impressively wide stretch of freeway for a city this size. 7 lanes wide on the eastbound side (though only 3 westbound lanes at this point). A bit down the road you have 5 westbound lanes and 6 eastbound lanes, for a total of 11 lanes wide. Wider than anything in Oregon, which is sad because Portland could sure use some wider freeways.

[empirestate]

What's interesting here is that so far, only the Dallas example creates the prohibition by signage alone. I've seen various other examples that use lane striping or even physical barriers to prohibit exiting, but in this case the exit is perfectly permissible except by the presence of that regulatory sign.

[bassoon1986]

I thought there was also an exit not accessible on I-35E in downtown Dallas just after the Mixmaster with I-30 I remembered seeing, but it's actually an exit repeated. Exits 428C and 428E are identical going northbound. Both are for Reunion Blvd and Commerce Street. 428E serves incoming I-30 traffic on the far left lanes, but you still theoretically could reach it from mainline I-35E, it just wouldn't be easy.

[nexus73]

I-84 Eastbound in Boise uses a separate ramp wrapping around the I-184 interchange for people wanting to exit at Cole Rd./Overland Rd. to avoid this problem. This is easy because it's a Y interchange, not 4 way so it did not require grade separation, but this is the right way to handle this. https://www.google.com/maps/@43.5929805,-116.2811057,808m/data=!3m1!1e3

This section also has an impressively wide stretch of freeway for a city this size. 7 lanes wide on the eastbound side (though only 3 westbound lanes at this point). A bit down the road you have 5 westbound lanes and 6 eastbound lanes, for a total of 11 lanes wide. Wider than anything in Oregon, which is sad because Portland could sure use some wider freeways.

Bingo!  110% agreement.  It would cost as much as a Ford-class CVN to redo PDX's freeways but what an improvement it would be.

Rick

[Brian556]

I remember the one in Downtown Dallas having a small green guide sign saying "DO NOT EXIT TO COMMERCE ST" Of course, a green sign is wrong for a regulatory message.

Also of interest it SB I-35E at Commonwealth. You have to move over two lanes that come in from SH 183 in a very short distance, but the movement is allowed and signed.
https://www.google.com/maps/@32.8165053,-96.8683976,3a,26.8y,157.59h,89.56t/data=!3m6!1e1!3m4!1s7iZGtoGJtX34OsJ69cjaFw!2e0!7i13312!8i6656

[peterj920]

This is I-43 north in Milwaukee.  Before the Marquette Interchange was rebuilt, I-43 north traffic could exit into this tunnel to Kilbourn Ave.  After the rebuild, only the ramp from I-94 East to I-43 North has access to this tunnel. 

https://www.google.com/maps/@43.0391545,-87.9248431,3a,37.5y,16.07h,83.06t/data=!3m6!1e1!3m4!1sc-XxMX3FKI1ZqbraEqN4mQ!2e0!7i13312!8i6656

In the same area, this is I-794 at Plankinton Ave where the mainline used to be able to exit.  After the Marquette Interchange rebuild, only the ramp from I-43 South, and I-43 North/I-94 West to I-794 East can exit here. 

https://www.google.com/maps/@43.0355706,-87.9170755,3a,75y,101.33h,73.59t/data=!3m6!1e1!3m4!1shgDL-tL2cfQrm0MU8ISAmA!2e0!7i13312!8i6656

This is on I-94 where I-294 North Ends, and traffic is prohibited from exiting onto Deerfield Rd.  (There is a tunnel exit underneath I-294 to Deerfield Rd about 1/4 mile earlier, so I don't know if this qualifies.)


https://www.google.com/maps/@42.157193,-87.8741961,3a,75y,8.26h,87.78t/data=!3m6!1e1!3m4!1s-vt9I2V1n2Q30nLWGRO5jQ!2e0!7i13312!8i6656?hl=en

[noelbotevera]

This is I-43 north in Milwaukee.  Before the Marquette Interchange was rebuilt, I-43 north traffic could exit into this tunnel to Kilbourn Ave.  After the rebuild, only the ramp from I-94 East to I-43 North has access to this tunnel. 

https://www.google.com/maps/@43.0391545,-87.9248431,3a,37.5y,16.07h,83.06t/data=!3m6!1e1!3m4!1sc-XxMX3FKI1ZqbraEqN4mQ!2e0!7i13312!8i6656

In the same area, this is I-794 at Plankinton Ave where the mainline used to be able to exit.  After the Marquette Interchange rebuild, only the ramp from I-43 South, and I-43 North/I-94 West to I-794 East can exit here. 

https://www.google.com/maps/@43.0355706,-87.9170755,3a,75y,101.33h,73.59t/data=!3m6!1e1!3m4!1shgDL-tL2cfQrm0MU8ISAmA!2e0!7i13312!8i6656

This is on I-94 where I-294 North Ends, and traffic is prohibited from exiting onto Deerfield Rd.  (There is a tunnel exit underneath I-294 to Deerfield Rd about 1/4 mile earlier, so I don't know if this qualifies.)


https://www.google.com/maps/@42.157193,-87.8741961,3a,75y,8.26h,87.78t/data=!3m6!1e1!3m4!1s-vt9I2V1n2Q30nLWGRO5jQ!2e0!7i13312!8i6656?hl=en

Why was traffic closed off from the top two examples up there when the Marquette was rebuilt? They could've made a flyover.

[Ace10]

I-84 Eastbound in Boise uses a separate ramp wrapping around the I-184 interchange for people wanting to exit at Cole Rd./Overland Rd. to avoid this problem. This is easy because it's a Y interchange, not 4 way so it did not require grade separation, but this is the right way to handle this. https://www.google.com/maps/@43.5929805,-116.2811057,808m/data=!3m1!1e3

This section also has an impressively wide stretch of freeway for a city this size. 7 lanes wide on the eastbound side (though only 3 westbound lanes at this point). A bit down the road you have 5 westbound lanes and 6 eastbound lanes, for a total of 11 lanes wide. Wider than anything in Oregon, which is sad because Portland could sure use some wider freeways.

Hopefully once all the construction is done around there the speed limit is raised from 65 mph. It sucks going 80 with 2 lanes and then dropping down to 65 on a super wide stretch of freeway that seems like it can easily handle faster speeds (and does given many drivers I see do 70-75 there). However I don't think that will happen because I believe Idaho's maximum urban freeway speed limit is 65, which is already faster than a lot of urban speed limits around the country (Seattle/New Orleans is 60, Portland is 55 and drops to 50 in the city center).

[odditude]

This is I-43 north in Milwaukee.  Before the Marquette Interchange was rebuilt, I-43 north traffic could exit into this tunnel to Kilbourn Ave.  After the rebuild, only the ramp from I-94 East to I-43 North has access to this tunnel. 

https://www.google.com/maps/@43.0391545,-87.9248431,3a,37.5y,16.07h,83.06t/data=!3m6!1e1!3m4!1sc-XxMX3FKI1ZqbraEqN4mQ!2e0!7i13312!8i6656

In the same area, this is I-794 at Plankinton Ave where the mainline used to be able to exit.  After the Marquette Interchange rebuild, only the ramp from I-43 South, and I-43 North/I-94 West to I-794 East can exit here. 

https://www.google.com/maps/@43.0355706,-87.9170755,3a,75y,101.33h,73.59t/data=!3m6!1e1!3m4!1shgDL-tL2cfQrm0MU8ISAmA!2e0!7i13312!8i6656

This is on I-94 where I-294 North Ends, and traffic is prohibited from exiting onto Deerfield Rd.  (There is a tunnel exit underneath I-294 to Deerfield Rd about 1/4 mile earlier, so I don't know if this qualifies.)


https://www.google.com/maps/@42.157193,-87.8741961,3a,75y,8.26h,87.78t/data=!3m6!1e1!3m4!1s-vt9I2V1n2Q30nLWGRO5jQ!2e0!7i13312!8i6656?hl=en

Why was traffic closed off from the top two examples up there when the Marquette was rebuilt? They could've made a flyover.

because flyovers are expensive, and it likely wasn't in the budget.

[doorknob60]

I-84 Eastbound in Boise uses a separate ramp wrapping around the I-184 interchange for people wanting to exit at Cole Rd./Overland Rd. to avoid this problem. This is easy because it's a Y interchange, not 4 way so it did not require grade separation, but this is the right way to handle this. https://www.google.com/maps/@43.5929805,-116.2811057,808m/data=!3m1!1e3

This section also has an impressively wide stretch of freeway for a city this size. 7 lanes wide on the eastbound side (though only 3 westbound lanes at this point). A bit down the road you have 5 westbound lanes and 6 eastbound lanes, for a total of 11 lanes wide. Wider than anything in Oregon, which is sad because Portland could sure use some wider freeways.

Hopefully once all the construction is done around there the speed limit is raised from 65 mph. It sucks going 80 with 2 lanes and then dropping down to 65 on a super wide stretch of freeway that seems like it can easily handle faster speeds (and does given many drivers I see do 70-75 there). However I don't think that will happen because I believe Idaho's maximum urban freeway speed limit is 65, which is already faster than a lot of urban speed limits around the country (Seattle/New Orleans is 60, Portland is 55 and drops to 50 in the city center).

EDIT: I read your comment wrong, I thought you said raised to 65. The below might not make as much sense. As nice as 70 or even 75 would be, and would really fit the flow of traffic, especially between Garrity Blvd and Meridian, I don't see it happening. I'm just glad the speed limit isn't 60 or 55, because I tend to gravitate to 70-75 here, which is mostly safe in the 65 zone. Though, that shitty section from Franklin in Nampa to Caldwell is a mess, and they need to upgrade that badly. I wouldn't want to see that part any higher than 65 in its current state; I sometimes question if 65 is too fast here (I say that, but I've certainly zoomed through it at 75 more than once).

It will for sure be 65 when it's done. The construction keeps "moving around" as they work on different parts of the highway. I've noticed a trend where when it drops down to 3 lanes (and shortly before), the speed limit drops to 55. When it gets its 4th lane back, it goes back up to 65. Right now (or, as of like a week ago), going eastbound, it jumps back up to 65 between the Meridian Rd. and Eagle Rd. interchanges (after dropping to 55 west of the Meridian interchange). But westbound, it's 55 from around the Cloverdale overpass all the way past Meridian Rd. And this changes constantly. But they're pretty good about putting 65 in some places even within the construction zone.

My biggest question is what will happen to the currently 55 zone between Broadway and Gowen. This 55 zone sucks, no reason for that one to be so low (the ones around Meridian make sense; this one I drove through at 80 a few weeks ago). Before the construction, it was 75 out here. I'm not sure if it was ever raised to 80 before they started construction. So, when it's done, will it go to 75, 80, or will they lower it to 65 to match the rest of the urban section?

[vtk]

In Columbus, northbound I-71 can't exit to 5th Ave; only traffic entering from Convention Ctr Dr, 4th St, or westbound I-670 may exit there.  A full concrete barrier makes it impossible (since the east segment of 670 was constructed in the 90s). On the southbound side, they braided the 5th Ave entrance ramp with the exit to 670; not sure why they didn't do similar braiding northbound.

[Duke87]

When I first saw the thread title I was thinking of something more like this:
https://www.google.com/maps/@39.0929178,-94.6405135,3a,75y,292.11h,97.59t/data=!3m6!1e1!3m4!1sZjb6kTyUDoz5hVxun6wW6g!2e0!7i13312!8i6656

where a ramp off an interstate leads directly into a place not open to the general public.

[peterj920]

This is I-43 north in Milwaukee.  Before the Marquette Interchange was rebuilt, I-43 north traffic could exit into this tunnel to Kilbourn Ave.  After the rebuild, only the ramp from I-94 East to I-43 North has access to this tunnel. 

https://www.google.com/maps/@43.0391545,-87.9248431,3a,37.5y,16.07h,83.06t/data=!3m6!1e1!3m4!1sc-XxMX3FKI1ZqbraEqN4mQ!2e0!7i13312!8i6656

In the same area, this is I-794 at Plankinton Ave where the mainline used to be able to exit.  After the Marquette Interchange rebuild, only the ramp from I-43 South, and I-43 North/I-94 West to I-794 East can exit here. 

https://www.google.com/maps/@43.0355706,-87.9170755,3a,75y,101.33h,73.59t/data=!3m6!1e1!3m4!1shgDL-tL2cfQrm0MU8ISAmA!2e0!7i13312!8i6656

This is on I-94 where I-294 North Ends, and traffic is prohibited from exiting onto Deerfield Rd.  (There is a tunnel exit underneath I-294 to Deerfield Rd about 1/4 mile earlier, so I don't know if this qualifies.)


https://www.google.com/maps/@42.157193,-87.8741961,3a,75y,8.26h,87.78t/data=!3m6!1e1!3m4!1s-vt9I2V1n2Q30nLWGRO5jQ!2e0!7i13312!8i6656?hl=en

Why was traffic closed off from the top two examples up there when the Marquette was rebuilt? They could've made a flyover.

Before the Marquette Interchange was rebuilt, traffic from those freeway to freeway ramps merged from the left, so there wasn't any crossover traffic with motorists trying to exit and merging traffic.  After the rebuild, all exits and merge points were on the right.  On I-43, a new ramp was built to Michigan Ave to replace access to the Kilbourn Tunnel, and on I-794, an exit was added to St Paul
Ave to replace Plankinton Ave.  The ramps are only there to replace the lost access, and they are not full interchanges.  The Marquette Interchange is a very large interchange as is in the middle of Downtown Milwaukee, and there are many flyover ramps in a small space.  There really wasn't a way to add them for local ramps due to space limitations.

[CNGL-Leudimin]

Heck, if an exit cannot be accessed from a mainline, don't number it as part of that, but instead number it as part of the road from which you actually can use the exit.

[Duke87]

There doesn't seem to be any actual restriction on the first one (google street view's vehicle seems to have no issue driving on that ramp and that service road), while the second one is actually strictly buses only (street view did not drive that ramp)

Street View did however have to make a U turn after taking that ramp. As I see it the reason the message is yellow and not white is because a cop cannot give you a ticket for using the ramp for non-railroad purposes. However since it leads to private property you may get in trouble for trespassing if you go there, should the railroad press charges.

[jp the roadgeek]

In the Hartford area, if there's a left hand entrance/exit with a right hand one within a mile, you'll see a sign like this on the entrance ramp.

https://goo.gl/maps/3kgiXpZjVrp

[Bruce]

Between exits 175 and 176 on I-5 in Shoreline, WA, there's a full diamond interchange serving a King County Metro bus base that you can't exit off at: https://www.google.com/maps/@47.7439181,-122.3297554,3a,49y,20.4h,86.76t/data=!3m6!1e1!3m4!1sIxi_JtAIC2tO6ChjxQd9yg!2e0!7i13312!8i6656

[roadman65]

For now the LEFT exit to South Street on Westbound I-4 in Downtown Orlando is one since the first day of construction of not so needed Amway Centre (as the former Amway was fine, but that is another story) as the exit was never reopened after the arena was completed.  The construction of that new not so needed indoor stadium is why the ramp closed as South Street itself was closed.  When South Street reopened either FDOT or the city decided to keep the jersey barriers in place and remove the brand new signage for that particular ramp that costed us taxpayers a pretty good penny to be made and installed.

[empirestate]

As I see it the reason the message is yellow and not white is because a cop cannot give you a ticket for using the ramp for non-railroad purposes. However since it leads to private property you may get in trouble for trespassing if you go there, should the railroad press charges.

I enjoy your suggestion that this much thought went into the selection of colors for this sign. :-)