When the traffic study was done in the mid-80s for that leg of 485, it was all farm land out there. They assumed a reasonable rate of traffic growth but they didn't/could have never foreseen the ballantyne/arboretum/rea road/johnston road population explosion.
The trouble with major new highway projects is that it takes about 20 years from conception to finish.
/our DOT is pretty good compared to most
when the DOT good ole boy network is salivating over/lobbying for the construction of an interchange for their own commercial development, well, they should have known. maybe that happens everywhere.