A Guide to Highway Interchanges
A great civil engineering bookmark is the two part study of highway interchanges at ‘The Infrastructurist’ (Part 1 and Part 2).
We can’t recommend enough The Infrastructurist as a blog in the fields of structural engineering, and civil engineering. They seem to be particularly big proponents of high-speed rail projects. They provide a nice daily wrap-up of links and articles related to the field.
A few of the most interesting highway interchanges (photos and descriptions from The Infrastructurist):
The Spaghetti Bowl – When we get into the realm of shapes and patterns that seem to be describable only by chaos theory or string theory. Spaghetti is a global phenomenon these days.
The Braid – This Maryland interchange is a stack design, but what’s unique about it is that the north and southbound segments of I-95 and east- and westbound segments of I-695 are actually braided over each other briefly in the middle of the interchange.
The Turbine – A “free-flow” style of exchange like the cloverleaf — that is, no traffic signals or intersections. This example is in Florida, at the junction of I-75 and I-4:
Why is it necessary to change the braided interchange into a stack interchange? I don’t see the need to do so unless it involves a major capacity upgrade (the braided, although rare, should have a good deal of capacity).