1 thought on “Basic Info Handout


    The premier interchange in and around Charlotte is the 4-level (so-called “stack”) interchange at the southern I-77/I-485 jct. This interchange is fully-directional (i.e. you always turn in the direction you intend to go). There is no other current or planned fully-directional F-F interchange in this area.

    The northern I-77/I-485 interchange is semi-directional: only SB-EB and EB-NB are directional. The other two left-turning movements require the motorist to navigate a loop. NCDOT does not plan to upgrade this interchange as part of the final leg construction btwn I-77 and I-85.

    The northern I-85/I-485 interchange is under construction. It’s going to be (my term) a pseudo-directional interchange. NCDOT calls it a turbine interchange. It’s almost fully-directional. Each left-turning movement is handled the same way – with a slight turn to the right before you curve left.

    The interchange planned for the I-77/I-40 upgrade (in Statesville) will almost be fully-directional too, but in a different way. Three left-turning movements will be directional; the fourth – EB-NB – will be a loop. Here’s how it will look: http://www.ncdot.gov/projects/i40i77Improvements/download/I_40_77_Fact_Sheet_web2.pdf

    AASHTO recommends fully-directional interchanges for Fwy-to-Fwy connections, but Congress won’t approve a fuel tax increase (or other suitable increase in highway revenue), so LOOPS will remain in vogue.

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