Most freeways that I can think of maintain a pretty good balance of entrances and exits, with most exits followed by an entrance aside from the odd half-diamond interchange or parclo (or other interchange configuration) with a 2-1 split.
But sometimes, things get a little quirky. I-390 south of Rochester is one example, where northbound at Exit 16 there are two exits followed by four consecutive entrances: Exits (https://www.google.com/maps/@43.1084423,-77.6119193,3a,75y,244.62h,86.76t/data=!3m6!1e1!3m4!1sNlFo-H_1KwHH7-kWZeGCMA!2e0!7i16384!8i8192!5m1!1e1) here (https://www.google.com/maps/@43.1083161,-77.6170198,3a,48.7y,295.62h,84.75t/data=!3m6!1e1!3m4!1sDWtLC7qvpA1hJxUuT-_aTg!2e0!7i13312!8i6656!5m1!1e1) followed by 1 (https://www.google.com/maps/@43.1102385,-77.6201419,3a,49.4y,326.93h,91.33t/data=!3m6!1e1!3m4!1s7iR_oHEahL5G9G-fCKjCNg!2e0!7i16384!8i8192!5m1!1e1) 2 (https://www.google.com/maps/@43.111888,-77.6226334,3a,48.6y,319.56h,89.77t/data=!3m6!1e1!3m4!1syjmcI04DDJZb2Xcz2-XJZQ!2e0!7i16384!8i8192!5m1!1e1) 3 (https://www.google.com/maps/@43.113443,-77.6270927,3a,48.9y,304.43h,86.33t/data=!3m6!1e1!3m4!1s79eJzUKC2qWXeFbFaDIPNA!2e0!7i16384!8i8192!5m1!1e1) 4 (https://www.google.com/maps/@43.1171014,-77.6346799,3a,49.1y,316.74h,88.18t/data=!3m6!1e1!3m4!1sGQhZCHJluUIJkoE0iRCaBA!2e0!7i16384!8i8192!5m1!1e1) entrances.
So what other examples are there? Is there anywhere that can beat four, or does this section of I-390 hold the official record?
And what about the reverse: most exits with no entrance? There's probably quite a few with three exits, but what about four, or more?
I-895 in Maryland.
Northbound has 6 consecutive entrances without any exits, starting at its southern terminus I-95, and not including that ramp itself.
Southbound has 7 consecutive exits without any entrances, starting just south of the tunnel.
4 entrances without any exits between exits 1D (US 50 West) and 2 (Harrison Ave) on NB I-75 in Cincinnati.
6 entrances without any exits between exits 134 (I-93) and 131 (Cambridge St) on WB I-90 in Boston.
I remembered all those the feeders into the Lincoln Tunnel from the Manhattan side (at least 7 of them), but unfortunately there is a left-hand off-ramp to 39th Street that crosses the on-ramp from the same street.
US-51 NB in Wausau, WI has consecutive exits for WI-29 west, Sherman Street, and WI-52/Stewart Avenue without an entrance.
After the "Last Exit Before Toll Bridge" (Exit 1) off-ramp on I-65 SB, there are three consecutive entrance ramps heading SB towards the bridge in Jeffersonville, IN.
The setup for the Metro Manila Skyway really fits this thread (especially the original Stage 1 of this road, which was primarily designed to feed commuters into Makati in the mornings and to suburbs at night) -
From the Alabang interchange north to Bicutan, there are three northbound onramps and three southbound offramps.
Further north, the northbound direction is ultimately slated to have 3 offramps in a row with no corresponding northbound onramp (Sgt. Rivera, A. Bonifacio/EDSA, NLEX), of which the latter 2 are already operational.
Quote from: sprjus4 on August 19, 2021, 07:38:27 PM
I-895 in Maryland.
Northbound has 6 consecutive entrances without any exits, starting at its southern terminus I-95, and not including that ramp itself.
Southbound has 7 consecutive exits without any entrances, starting just south of the tunnel.
Wow, that's incredible. Going northbound you literally cannot get off anywhere between I-95 and the tunnel toll plaza. You're pretty much committed to the tunnel once you get off at I-895. I'm surprised I've never noticed that before.
There's something similar (but less extreme) going on with the southern end of I-295 in Maine. Southbound has
three consecutive exits (https://www.google.com/maps/@43.6316398,-70.322678,15.08z/data=!5m1!1e1), with no entrances at all between US 1 and I-95. Northbound also has three straight entrances, but it's a little less impressive because there is an exit to the Turnpike approach.
Quote from: webny99 on August 20, 2021, 09:34:55 AM
Quote from: sprjus4 on August 19, 2021, 07:38:27 PM
I-895 in Maryland.
Northbound has 6 consecutive entrances without any exits, starting at its southern terminus I-95, and not including that ramp itself.
Southbound has 7 consecutive exits without any entrances, starting just south of the tunnel.
Wow, that's incredible. Going northbound you literally cannot get off anywhere between I-95 and the tunnel toll plaza. You're pretty much committed to the tunnel once you get off at I-895. I'm surprised I've never noticed that before.
There's something similar (but less extreme) going on with the southern end of I-295 in Maine. Southbound has three consecutive exits (https://www.google.com/maps/@43.6316398,-70.322678,15.08z/data=!5m1!1e1), with no entrances at all between US 1 and I-95. Northbound also has three straight entrances, but it's a little less impressive because there is an exit to the Turnpike approach.
Oh, here's another one: I-90 (Chicago Skyway).
Once you get off of the Dan Ryan Expressway heading EB, there isn't another exit until you pass the toll plaza. 5 entrance ramps prior to the toll plaza and two exit ramps after the toll plaza.
It's reversed going the other way: once you pass exit 0 for Indianapolis Blvd on the Indiana Toll Road, there isn't another exit until you pass the toll plaza. 2 entrance ramps prior to the toll plaza and five exit ramps after the toll plaza.