RIRO Intersections

[sparker]

There's a few in San Mateo on US-101

In Vancouver, WA-500 has had all of its signals removed between I-5 and I-205.  Many of the intersections are just RIRO.

Here's one in Commerce, CA on I-5.

Fixed the links for you.

I wouldn't describe the two CA instances as true RIRO's; they're more "folded diamonds", although the I-5 example is pretty "scrunched up" between the NB carriageway and Telegraph Road (I've used the offramp several times, it's a real PITA!).  There are some remaining RIRO's on CA 99, notably north of Delano and in Chowchilla. 

Disagree.  They look like RIROs to me.  The one on US-101 doesn't even have a corresponding exit on the other side of the highway.  Hardly a diamond at all, folded or not.  For the one on I-5, the two sides of the highway don't even connect to the same road;  but it's an edge case, because they look a lot like Oklahoma City's exits to frontage roads on I-35.

A folded diamond interchange has loop ramps.

It's possible to be both a folded diamond and a RIRO.  Same for cloverleaf and RIRO.

I suppose so -- but what, in my view, differentiates a RIRO from a standard set of ramps to an intersecting and/or frontage road is (a) the severity of the curves on the ramp (I'd generally say a RIRO requires <15mph), (b) the length of the approach ramp (exit) and acceleration ramp (entrance), and (c) whether such ramps are physically separated from the freeway's main lanes.  Shortcut: if a stop sign is required at entrance, it's by default a RIRO!  By those standards -- and I don't presume that there's universal agreement there -- the two CA ramps are not RIRO's.  BTW, I would consider the nearly right-angle ramps (those yet unreconstructed) along I-10 from I-710 out through Rosemead Blvd. (more or less CA 19 depending upon relinquishment status at any given moment!) to be RIRO's, if not for the fact that all of them utilize C/D lanes (an early version of such) to separate them from the actual freeway lanes.  Still, they should have been upgraded years if not decades ago. 

[GenExpwy]

Just my opinion: the key distinction is simply whether there is any physical gore. Even the most minuscule physical gore (the cluster of signs in NY 17 exit 108) makes the thing a "severely substandard partial interchange" . A RIRO means there is literally nothing more than lines painted on a swath of pavement (NY 17 exit 111).

[kphoger]

And see, for me, a big criterion is that, at a RIRO, one cannot directly cross the highway on the crossroad.

The US-101 example is a RIRO, in part because one cannot cross the highway on Kehoe Ave.

The I-5 example is a maybe, because one can cross the highway on Triggs St but not Telegraph Rd.

The I-68 Maryland Ave example is a classic double RIRO.