I may be putting words in OPs mouth here but I imagine he meant not putting parallel taxiways so close to the main runway. I know that space restrictions make

I may be putting words in OPs mouth here but I imagine he meant not putting parallel taxiways so close to the main runway. 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 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?)