BE24 PLT BECAME DISORIENTED AS HE TAXIED AT NIGHT AND USED WRONG UNLIGHTED RWY FOR TKOF.

Narrative

I WAS PRACTICING SOLO NIGHT LNDGS AT CCR WITH THE TWR IN OP. RWY 19R WAS IN USE. I HAD JUST LANDED ON RWY 19R AND WAS INSTRUCTED TO MAKE A R TURN OFF THE RWY ONTO TXWY K; THEN R ON TXWY E BACK TO RWY 19R. THIS AREA IS ON THE W RAMP WHICH IS UNDER CONSTRUCTION. MY ACFT IS HANGARED ON THE E RAMP AND IS THE AREA THAT I USE ALMOST EXCLUSIVELY. TXWY AND RWY MARKINGS AND LIGHTING ON THE W RAMP ARE MARGINAL AND FRANKLY CONFUSING TO ME. AS I CONTINUED DOWN TXWY E; MY LNDG LIGHT PICKED UP A YELLOW LINE CURVING TO THE R; SO I FOLLOWED IT AND SOON NOTICED THAT I WAS ON THE RWY. I ASSUMED IT WAS RWY 19R BUT DID NOT VERIFY THAT WITH TXWY OR RWY SIGNAGE OR THE HDG ON MY HSI. CONCORD TWR CLRED ME FOR TKOF; AND I DID BUT ONLY REALIZED ONCE AIRBORNE THAT I WAS USING RWY 14 WHICH WAS UNLIGHTED. THE TKOF WAS OTHERWISE UNREMARKABLE; AND I ADVISED THE TWR THAT I HAD JUST DEPARTED ON RWY 14 (L; I THINK). THERE WAS NO OTHER TFC ON THE GND ON THE GND OR TWR FREQS. THE TWR MADE NO COMMENT ABOUT MY UNAUTH DEP; AND I COMPLETED MY NIGHT LNDG SEQUENCE WITHOUT FURTHER INCIDENT. AS USUAL; MANY FACTORS CONTRIBUTED TO THIS INCIDENT. IRONICALLY; I OWN A PORTABLE GPS WITH TXWY POS GUIDANCE BUT DID NOT BRING IT WITH ME THIS NIGHT; AS THE FLT WAS RATHER IMPROMPTU. NEXT; I SHOULD HAVE DECLINED THE R TURN ONTO THE W RAMP AREA AND REQUESTED A L TURN ONTO TXWY A; ONE I AM MORE FAMILIAR WITH. THEN WHEN I NOTICED I WAS DISORIENTED; I SHOULD HAVE CHKED MY HSI HDG AND/OR REQUESTED GUIDANCE FROM THE GND CTLR. FORTUNATELY; I WAS THE ONLY ACFT IN MOTION ON OR NEAR THE ARPT; SO THERE WAS NO CONFLICT AND NO INJURIES OR DAMAGE.