Longest on/off ramps

[jlam]

I don't know whether this is the longest in Colorado, but the I-76 EB to I-25 NB ramp is 1.5 miles long, maybe a bit longer.
https://tinyurl.com/longramp

[MCRoads]

BUMP!

Found a contender for the longest ramp ever! Exit 294 from I-15 to WB I-215 in SLC: 4 miles!

[Terry Shea]

EB I-96 on ramp to EB I-69 is quite long.  I believe it's just over 2 miles.

[rower155]

EB I-96 on ramp to EB I-69 is quite long.  I believe it's just over 2 miles.

That is a long one. If we're measuring to the painted gore nose like the other one, then it is 2.5 miles.

Funny seeing I-69 EB, but this segment is posted that way. I'm somehow guessing that's been discussed on this forum before.

[formulanone]

BUMP!

Found a contender for the longest ramp ever! Exit 294 from I-15 to WB I-215 in SLC: 4 miles!

If I encountered that for the first time, I'd swear the signs were lying to me.

[webny99]

BUMP!

Found a contender for the longest ramp ever! Exit 294 from I-15 to WB I-215 in SLC: 4 miles!

If I encountered that for the first time, I'd swear the signs were lying to me.

Except that it's more of a service road than a ramp, and you'd know what you were in for when you saw this sign.

[US 89]

BUMP!

Found a contender for the longest ramp ever! Exit 294 from I-15 to WB I-215 in SLC: 4 miles!

If I encountered that for the first time, I'd swear the signs were lying to me.

That was reconstructed just last year - creating essentially a very long C/D ramp in order to alleviate the awful weaving and congestion that was an everyday occurrence between 90th South and 215 with the 72nd South interchange in the middle. In my experience, it has worked wonders. Only interesting thing about it is that once you're on it, there's no easy way to get back on 15.

The funny thing is that going north, you now pass exit 295 before you cross the roads that 294 goes to (294A for 72nd South, 294B-C for I-215). Those exits are still in order going southbound... but as 298A-B for I-215 and 297 for 72nd South.

[MCRoads]

BUMP!

Found a contender for the longest ramp ever! Exit 294 from I-15 to WB I-215 in SLC: 4 miles!

If I encountered that for the first time, I'd swear the signs were lying to me.

That was reconstructed just last year - creating essentially a very long C/D ramp in order to alleviate the awful weaving and congestion that was an everyday occurrence between 90th South and 215 with the 72nd South interchange in the middle. In my experience, it has worked wonders. Only interesting thing about it is that once you're on it, there's no easy way to get back on 15.

The funny thing is that going north, you now pass exit 295 before you cross the roads that 294 goes to (294A for 72nd South, 294B-C for I-215). Those exits are still in order going southbound... but as 298A-B for I-215 and 297 for 72nd South.

I thought it was a CD road as well, but it actually isn't! Once you get off I-15 on exit 194, you cannot re-enter the highway! For a ramp this long, I would personally put a "NO RE-ENTRY"  placard on the sign, but I don't know if such a thing exists.

[kphoger]

For a ramp this long, I would personally put a "NO RE-ENTRY"  placard on the sign, but I don't know if such a thing exists.

Why?  You only realize how long it is after you're already on it, at which point the whole "no re-entry" part is just like any other system interchange ramp.

[MCRoads]

For a ramp this long, I would personally put a "NO RE-ENTRY"  placard on the sign, but I don't know if such a thing exists.

Why?  You only realize how long it is after you're already on it, at which point the whole "no re-entry" part is just like any other system interchange ramp.

I guess. Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction. But I'm sure there is already a thread where this is described in more detail.

I do believe I found the longest ramp in Colorado: I-25 NB to I-70 WB. 1.6 miles.

[kphoger]

Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction.

Precisely.  Like this.

[webny99]

Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction.

Precisely.  Like this.

Or this. But I wouldn't have any issue with this type of sign being used at the Utah example.

[kphoger]

I suppose it isn't only an exit ramp, now that I'm looking at it closely.  Technically, 1.6 miles of it also serves as a connector road between 9000 South and 7200 South.

Does this disqualify it?

[davewiecking]

I suppose it isn't only an exit ramp, now that I'm looking at it closely.  Technically, 1.6 miles of it also serves as a connector road between 9000 South and 7200 South.

Does this disqualify it?

I'd say it's a C-D road. I-215 exit doesn't start until the 7200 exit has split off. But I'm not the OP...

[webny99]

I suppose it isn't only an exit ramp, now that I'm looking at it closely.  Technically, 1.6 miles of it also serves as a connector road between 9000 South and 7200 South.

Does this disqualify it?

I'd say it's a C-D road. I-215 exit doesn't start until the 7200 exit has split off. But I'm not the OP...

But it's only a C/D road if it connects back to I-15.. and around we go.

[US 89]

Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction.

Precisely.  Like this.

Or this. But I wouldn't have any issue with this type of sign being used at the Utah example.

I would. We don't put "no re-entry" signs at every system interchange exit, do we? Putting a sign like that would probably cause more confusion than it's worth.

Plus you can use the 72nd South exit to get back on mainline 15. It's just a little more complicated than "exit and drive straight through" because it's a SPUI, so you have to turn right and then u-turn at the first legal point. Those signs should be reserved for interchanges where there is no ramp from a surface cross street back to the interstate in the same direction, as is the case with both of the signs linked above.

[webny99]

Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction.

Precisely.  Like this.

Or this. But I wouldn't have any issue with this type of sign being used at the Utah example.

I would. We don't put "no re-entry" signs at every system interchange exit, do we? Putting a sign like that would probably cause more confusion than it's worth.

Plus you can use the 72nd South exit to get back on mainline 15. It's just a little more complicated than "exit and drive straight through" because it's a SPUI, so you have to turn right and then u-turn at the first legal point. Those signs should be reserved for interchanges where there is no ramp from a surface cross street back to the interstate in the same direction, as is the case with both of the signs linked above.

How would it create more confusion? It's different than a regular system interchange ramp because it's way longer, obviously, plus as kphoger mentioned it's used to connect between 9000 South and 7200 South. So it's basically like a C/D road with no re-entry, and I don't see how that's different than a regular off-ramp with no re-entry. In both cases, you would expect there to be re-entry. The only reason there's not here is because both sets of SPUI ramps are inside the 215 access road, so they have their own ramps to 15 NB in place of what would normally be a slip ramp from the C/D road.

[kphoger]

I would. We don't put "no re-entry" signs at every system interchange exit, do we? Putting a sign like that would probably cause more confusion than it's worth.

Plus you can use the 72nd South exit to get back on mainline 15. It's just a little more complicated than "exit and drive straight through" because it's a SPUI, so you have to turn right and then u-turn at the first legal point. Those signs should be reserved for interchanges where there is no ramp from a surface cross street back to the interstate in the same direction, as is the case with both of the signs linked above.

How would it create more confusion? It's different than a regular system interchange ramp because it's way longer, obviously, plus as kphoger mentioned it's used to connect between 9000 South and 7200 South. So it's basically like a C/D road with no re-entry, and I don't see how that's different than a regular off-ramp with no re-entry. In both cases, you would expect there to be re-entry. The only reason there's not here is because both sets of SPUI ramps are inside the 215 access road, so they have their own ramps to 15 NB in place of what would normally be a slip ramp from the C/D road.

1.  It only serves as a C/D road for traffic not coming from I-15.  Therefore, its function in that regard is meaningless to traffic on I-15–which is where you're suggesting such a sign be placed.  For I-15 traffic, it's simply an exit for two different roads, much like the ramp from SB I-135 to 29th/Hydraulic and EB K-96 here in Wichita.

2.  Length doesn't matter (despite what your cousin told you in seventh grade).  Drivers don't know the ramp is really long until they're already on it anyway.

3.  A regular off-ramp with no immediately apparent re-entry doesn't generally get additional signage.  That's basically any old partial diamond interchange, such as SB I-135 at Central here in Wichita.  Examples like Airport Rd in northern Oklahoma are more rare.

[SEWIGuy]

Maybe a more apt use for a placard like that is if the exit you are taking does not allow for convenient re-entry on the same highway in the same direction.

Precisely.  Like this.

Or this. But I wouldn't have any issue with this type of sign being used at the Utah example.

I would. We don't put "no re-entry" signs at every system interchange exit, do we? Putting a sign like that would probably cause more confusion than it's worth.

Plus you can use the 72nd South exit to get back on mainline 15. It's just a little more complicated than "exit and drive straight through" because it's a SPUI, so you have to turn right and then u-turn at the first legal point. Those signs should be reserved for interchanges where there is no ramp from a surface cross street back to the interstate in the same direction, as is the case with both of the signs linked above.

How would it create more confusion? It's different than a regular system interchange ramp because it's way longer, obviously, plus as kphoger mentioned it's used to connect between 9000 South and 7200 South. So it's basically like a C/D road with no re-entry, and I don't see how that's different than a regular off-ramp with no re-entry. In both cases, you would expect there to be re-entry. The only reason there's not here is because both sets of SPUI ramps are inside the 215 access road, so they have their own ramps to 15 NB in place of what would normally be a slip ramp from the C/D road.

Because the purpose behind those signs is to let the driver know they can't get back on the highway in the same direction they were going if they decide to exit there.  It's not the same thing in this case.  It's just a long exit ramp. 

[kphoger]

Because the purpose behind those signs is to let the driver know they can't get back on the highway in the same direction they were going if they decide to exit there.  It's not the same thing in this case.  It's just a long exit ramp. 

Right.  The ability to re-enter I-15 in this manner is functionally equivalent to being able to re-enter I-135 in this manner.

Should there be a "no re-entry" sign at, say, this exit?  Or this exit?

[michravera]

Some long NorCal examples:

Alemany Maze, San Francisco
- US 101 north to I-280 north/I-280 south to US 101 south, about 0.8 mile
https://www.google.com/maps/dir/37.7256378,-122.4018352/37.7365759,-122.4035067/@37.7331256,-122.4089485,18z/data=!4m2!4m1!3e0
- US 101 north to I-280 south (in the same ramp complex)
https://www.google.com/maps/dir/37.7256378,-122.4018352/37.7336216,-122.41176/@37.7281875,-122.4158139,15z/data=!4m2!4m1!3e0

- I-280 north to Cesar Chavez (Army) Street. 0.6 miles long
https://www.google.com/maps/dir/37.7430685,-122.3967389/37.7498776,-122.3923004/@37.7430069,-122.3970986,20z/data=!4m9!4m8!1m5!3m4!1m2!1d-122.3967457!2d37.7430994!3s0x808f7faa33bcac13:0xa42eadb57840c4f4!1m0!3e0

San Francisco International Airport
- US 101 south to SFO, 1.9 miles
https://www.google.com/maps/dir/37.6373054,-122.4046866/37.6145443,-122.3928695/@37.6303659,-122.4176733,15z/data=!4m9!4m8!1m5!3m4!1m2!1d-122.4037029!2d37.6334908!3s0x808f79d31ba90a0f:0xfc0c1949e1a98bf!1m0!3e0
- I-380 east to SFO (shared with above ramp), 2 miles
https://www.google.com/maps/dir/37.6338166,-122.4109707/37.6145443,-122.3928695/@37.6266534,-122.4128968,15z/data=!4m9!4m8!1m5!3m4!1m2!1d-122.4041392!2d37.633247!3s0x808f79d266a7ba49:0xe2c10341702ba369!1m0!3e0
- SFO to I-380 west, 2 miles
https://www.google.com/maps/dir/37.6147596,-122.393454/37.6342734,-122.4115633/@37.5825502,-122.4255815,15z/data=!4m2!4m1!3e0

- I-280 south to San Bruno Avenue, 0.7 miles
https://www.google.com/maps/dir/37.6317857,-122.4369861/37.6241043,-122.4288966/@37.6275032,-122.4347545,16z/data=!4m2!4m1!3e0

- I-680 south to US 101 south in San Jose, 1.4 miles
https://www.google.com/maps/dir/37.3442738,-121.8454671/37.3295925,-121.8424148/@37.3440666,-121.8450287,17z/data=!4m2!4m1!3e0

- I-80 east to I-880 south (MacArthur Maze) in Oakland, 1.6 miles.
https://www.google.com/maps/dir/37.8232347,-122.3169174/37.8156239,-122.2998573/@37.8334997,-122.3541215,14z/data=!4m2!4m1!3e0

- Route 92 east to I-880 north in Hayward, 1.2 miles
https://www.google.com/maps/dir/37.6346492,-122.1040562/37.6473967,-122.0954848/@37.6349005,-122.1002164,17z/data=!4m2!4m1!3e0

- I-238 west to I-880 south, San Lorenzo, 1.2 miles
https://www.google.com/maps/dir/37.6897775,-122.1198918/37.68547,-122.1307131/@37.6895012,-122.1313276,16z/data=!4m2!4m1!3e0

I-880 south to CASR-237 west HOV-to-HOV connector physically joins the mainline much sooner, but logically (due to movement restrictions, etc) is close to 4 miles. I am sure that several HOV-to-HOV connectors, some of which have completely separate roadways, in Southern California are even longer still.

[thenetwork]

For the Cleveland area, I will chime in on two ramps: 

- WB-I-480 to NB SR-176/Jennings Freeway
- SB SR-176 to EB I-480

Both are well over a mile long, and parallel I-480 for a bit before connecting to the Jennings Freeway.

[webny99]

Because the purpose behind those signs is to let the driver know they can't get back on the highway in the same direction they were going if they decide to exit there.  It's not the same thing in this case.  It's just a long exit ramp. 

Right.  The ability to re-enter I-15 in this manner is functionally equivalent to being able to re-enter I-135 in this manner.

In most cases, the main reason for exiting a highway and then immediately re-entering would be for a fuel/food/restroom stop. That's obviously not the case when you're exiting to another freeway, but in the case of a C/D road, there are other reasons to exit and then re-enter, such as availability of more exits if you need to get off, or to bypass congestion if the mainline happens to be more congested. So, point taken, but I still don't think it would hurt to notify drivers that it is not a C/D road, and "no re-entry" would seem to be the simplest way to do that.

Should there be a "no re-entry" sign at, say, this exit?  Or this exit?

No to the first one, because there's re-entry from NY 96 that's considered part of the same interchange. It requires one extra turn, but it's well-signed.

Yes to the second one, as it's similar to the examples in CO and PA that you and I linked to upthread.

[US 89]

In most cases, the main reason for exiting a highway and then immediately re-entering would be for a fuel/food/restroom stop. That's obviously not the case when you're exiting to another freeway, but in the case of a C/D road, there are other reasons to exit and then re-enter, such as availability of more exits if you need to get off, or to bypass congestion if the mainline happens to be more congested. So, point taken, but I still don't think it would hurt to notify drivers that it is not a C/D road, and "no re-entry" would seem to be the simplest way to do that.

Okay, but nobody on that thinks it's a C/D road. The only ways onto there are the direct ramp from I-15 itself and the on-ramp from 90th South, and both of those are clearly identified as being not I-15. Nobody is going to go under those signs and assume they'll be able to merge right back onto I-15. As others have mentioned, it looks like a ramp on the signs, and you don't realize how long it is until you're already on it.

[ilpt4u]

It isn't signed as an exit, and its original intent was not to be an exit but reversible Express Lanes along I-70 that crossed the Mississippi River on the Poplar Street Bridge, but it now functions as a really, really, really long exit "ramp"  from I-70 EB to I-44 WB:

The Eastbound I-70 Express Lanes in St Louis. They are no longer reversible/are permanent Eastbound/Inbound. They leave Mainline I-70 at MM 244.4. They never rejoin I-70, as I-70 TsOTSO onto the Stan Musial Veterans' Memorial Bridge, at MM 249.4. The Express Lanes rejoin the Freeway after it becomes the Eastern Origin of I-44, at I-44 MM 292.6. I-44's Easternmost MM is 293.2

The EB 70 TOTSO is not signed as an exit, but continuing onto WB 44 is signed as Left Exit 249A at the origin point of I-44

I think the Express Lanes should be signed as an early exit for I-44 WB and To SB I-55, since there is no access from the Express to continue on Mainline I-70 via the Stan Span

My math says these Express Lanes make up a 5.6 mile exit ramp from I-70 EB to I-44 WB

There are no "return"  ramps to Mainline EB I-70 the full length of the Express Lanes