My first RIRO post was not referring to entrance/exit configurations that were essentially half a folded diamond, but rather streets that intersect a freeway/expressway without curved or banked ramps that allow exits and entrances greater than about 10-15mph -- like the old frontage road "interchanges" on CA 99 betgween Manteca and Stockton, now removed with the revamping of that highway. IIRC, there's one remaining between Delano and Tulare as well NB. Attempting high speed on any of those would put the driver into either the chain-link fence between the main lanes and the frontage road or spinning out into one of the adjoining fields! The now-defunct ones north of Manteca also included stop signs (and very short merging lanes) at the freeway entrance.