Auxiliary ramps and advance signage/exit numbering

[TheStranger]

This is probably common in urban areas, but I've always been curious about "sub-ramps" to a primary interchange, i.e. they exist to provide extra access from a much more important junction, yet are not signed until the ramp themselves.

Sacramento has  a couple of examples of this:

- Broadway/X Street exit off of the Route 99 transition ramp from I-5 southbound to US 50, not signed at all from I-5 southbound
- 34th Street exit off of the ramp from Business 80 westbound to US 50 eastbound, not signed from Business 80

One in San Francisco that comes to mind is the Alemany Boulevard ramp off of the ramp from US 101 south to I-280 south...

In other states, is signage for these auxiliary ramps more pronounced, or given an exit # to go along with the primary interchange?

[Brandon]

There are a few such auxiliary ramps around Chicago.
The Tollway seems to sign them along with the primary exit.
Examples:
- Exit from WB I-88 to SB-355 has a ramp to Ogden Avenue.  It is signed along with the I-355 exit at the interchange, and signed before the exit as well.
- Exit from NB I-294 to SB I-55 has a ramp to Wolf Road (actually, it is the original ramp - I-55's was tacked on later).  It is signed with the I-55 exit in advance.

IDOT doesn't have many of these.  One I can think of off hand is Wentworth Avenue off the I-94/I-57 Split.  It is signed with auxiliary signs before the split, and signed with primary signs after the split.  This exit lacks an exit number.

[akotchi]

I know of a couple of cases in my travels, in multiple states.

If the minor ramp is to a numbered route, then the route has been included in the advance guide signing.  No separate exit number is provided for this minor ramp.

[Duke87]

The I-95/I-287 Interchange in Rye, NY has a case of this, and the configuration makes for some interesting quirks. Northbound, drivers will encounter Exit 20 for US 1 south, Exit 21 for I-287 west and US 1 north, and Exit 22 for Midland Avenue. Southbound there is only one exit: 21, for I-287. Midland Avenue is then accessed by a ramp off the ramp to I-287 - the exit is not numbered, and there is no advance signage for it. No direct connection to US 1 exists.
Even odder is that to get from Midland Avenue to 95 south, one must get on 287 west and then take an exit shortly afterward... meaning traffic that has just exited 95 south to get on 287 has a chance to "change its mind" and get back on 95 south.

In the same area, the ramp from I-287 east onto I-684 has a little branch to Westchester Avenue (the service road). This one, however, is mentioned on the advance signage.

Westbound on the Cross Bronx (Southbound on I-95), exit 1C can be used not only to get to I-87, but also to access the Washington [Heights] Bridge. This is on advance signage as "Amsterdam Avenue" (where the west end of the bridge is). A pair of ramps on the west end also allow you to re-enter I-95, so it can also be used as an alternative to the Alexander Hamilton Bridge, although this is a pretty well-kept secret.
That Branch has no unique exit number, however, the other two branches for I-87 north and south are, despite being branches off of exit 1C, exits 3N and 3S. Not to be confused with the actual exit 3 a mile and change to the east which is unrelated.

[vdeane]

Actually, 1C is exit 3.  NY tried to renumber I-95 to sequential, but stopped after only partially converting three exits.

[njroadhorse]

On I-280 in Newark this happens, too.  Exit 12 is for the Garden State Parkway, and according to the BGS eastbound, only the GSP.  Once you exit, you find that you can access the surface street parallel to the Parkway, Oraton Parkway, but not until the gore point for the Oraton off-ramp.

[74/171FAN]

On I-95 in Fredericksburg, the exit for VA 3 WB(Exit 130B) also has an exit for Carl D. Silver Pkwy but no signs for it until the exit

[Bryant5493]

Access to Cumberland Blvd. isn't denoted from I-285 to I-75 South, until taking the I-75 South access road.


Be well,

Bryant

[jdb1234]

No warning is given for I-20 Eastbound exits for US 11 until after the split with I-59.  US 11 only has access to I-20 West I-59 South via Deadman's Curve at this interchange.

[Alps]

Many NJ freeway to freeway interchanges have local access thrown in.  My very own exit, Smith Rd. from I-80 WB, is not signed until you get to the I-287 ramp gore.  I believe you have the same problem on I-287 NB to I-80 EB with the same Smith Rd. 

[Mr_Northside]

At some point local access was added to a county route at the I-80/I-76 "bump" outside of Youngstown.  It was done in such a way that it only allows access to/from the Ohio Turnpike (More than likely because they were the ones who built it).

[mightyace]

At some point local access was added to a county route at the I-80/I-76 "bump" outside of Youngstown.  It was done in such a way that it only allows access to/from the Ohio Turnpike (More than likely because they were the ones who built it).

Good memory!

Also, the ramps to/from "County Road 18" are the ramps from the original turnpike exit at this location.  (The ramps to the modern exit and the turnpike are, of course, new)

IIRC Before the cross I-76 West and I-80 East freeway was built, the turnpike exited to what was then OH 18.  The bridge over the turnpike for that exit may still be in place and remnants of the ghost ramps can still be seen.

[realjd]

At the I-469 interchange with I-69 on the north side of Fort Wayne, IN, there's a long local exit that snakes back for a while to connect with Auburn Road, a small local road. It's an off-ramp only with no corresponding on-ramp. It is given a number (31-C) and is clearly signed at the interchange itself, but doesn't appear on the advanced signage along I-469.

http://maps.google.com/?ie=UTF8&ll=41.167542,-85.105376&spn=0.023874,0.038581&z=15

[njroadhorse]

Many NJ freeway to freeway interchanges have local access thrown in.  My very own exit, Smith Rd. from I-80 WB, is not signed until you get to the I-287 ramp gore.  I believe you have the same problem on I-287 NB to I-80 EB with the same Smith Rd. 

Yes you do, IIRC. 

[mightyace]

Akron, OH used to have one at the "Central Interchange" of I-76, I-77 and OH 8 on the ramp from OH 8 south to I-76 West, I-77 North multiplex to Johnson St.

According to Google Streetview, this ramp is now closed.
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=akron,+oh&sll=37.0625,-95.677068&sspn=50.910968,114.169922&ie=UTF8&hq=&hnear=Akron,+Summit,+Ohio&ll=41.063045,-81.505487&spn=0.01194,0.027874&t=h&z=16&layer=c&cbll=41.063109,-81.505396&panoid=L9CHNKmZtadMAejIuJ1fDA&cbp=12,233.57,,0,13.94

Back in the day, IIRC there was just a small sign by the ramp and maybe the BGS at the split of the I-76 E-W ramps with Johnson St. on it.