Per the NCRoute Changes website on 11/3/10
http://www.ncdot.gov/doh/preconstruct/traffic/safety/reports/RTE/NC53_20101103.pdf (http://www.ncdot.gov/doh/preconstruct/traffic/safety/reports/RTE/NC53_20101103.pdf)
NC 53 has been extended in Jacksonville:
East along NC 24 Bypass to Western Blvd, then northwest back across US 17 Bus and ending at SR 1308 Gum Branch Rd.
I guess they didn't want to wait for the Northwest Loop (currently unfunded) to be built to put NC 53 on Western Blvd. Otherwise it doesn't make much since to wrap NC 53 all the way around Jacksonville like that. Western Blvd could have just gotten a new number...
Mapmikey