Obviously this question only has four possible answers, and I'm about to rule out two of them, but are there any places where more than three share the same route? I almost hope not.
In Cambridge, MA, south/east/west of the Alewife Station intersection of 2 and Alewife Brook Parkway, there are three on one route:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.staticflickr.com%2F2829%2F9631227657_dabe6a7c09.jpg&hash=ba673fc2fafb21601f591d1eaea5d2b65c4dd2ae)
I'm inclined to think the answer is 3. I'm sure this topic has come up here before, and I think the consensus was that if a four-way concurrency did exist, it doesn't anymore.
But examples of three-way concurrencies are surprisingly numerous.
Eons ago, someone on MTR posted an example of all four directions at one time, and I want to think it was in Massachusetts. However, searches of MTR yield nothing because apparently the poster had "no-archive" enabled and DejaNews, Google's forerunner for Usenet searches, therefore didn't archive it.
HB always replies with the same story, and I'm inclined to think either he misinterpreted the post or the original author misinterpreted a sign.
Quote from: NE2 on August 31, 2013, 03:12:35 AM
HB always replies with the same story, and I'm inclined to think either he misinterpreted the post or the original author misinterpreted a sign.
Possibly the latter, because I remember the original MTR poster included the route numbers and direction of travel. And I remember finding the location on the map.