Maybe taxiways parallel to runways shouldn't be a thing.
I know that space restrictions make this very tenuous but I must admit that looking at the overhead on https://ntsb.gov/investigations/Pages/DCA17IA148.aspx that the taxiway marked C looks a lot more like a runway than the one marked F. (due to the width maybe?)
Can't the taxiways be not straight, like have a slight zig zag to them, so that they're easily distinguishable from a runway? Not ridiculously zigzagged, but maybe 3 or 4 angles of 15 degrees along the length or something would do it.