BWI GND CTL ISSUED TAXI CLRNC CONFUSES B737 WHEN EXITING RWY 33. SIGNAGE CONFUSION FOCUSED AT INTXN A; P1 AND P. RPTR CLAIMS SIGNAGE FOR P AND P1 AT TXWY A DIRECTS ACFT INCORRECTLY.

Narrative

WE JUST LANDED AT BWI RWY 33L AND CLRED THE RWY AT TXWY F. I TALKED TO GND; AND THEY QUICKLY SPOUTED OFF A CLRNC TO; 'TAXI A; P1; P TO THE RAMP.' I SAID; 'COULD YOU SAY IT AGAIN;' (SINCE THIS IS NEVER A NORMAL CLRNC TO PARK AT BWI). GND SAID THE CLRNC AGAIN; BUT MUCH SLOWER; 'TAXI A; P1; P TO THE RAMP. BASICALLY; YOU JUST GO AROUND THE BACKSIDE OF THE FIREHOUSE.' WE TAXIED SLOWLY VIA ALPHA AND WENT BEHIND THE FIREHOUSE (WHICH ON THE COMMERCIAL CHART PAGE IS THE WHITE 'DIAMOND' TO THE R OF THE A R P (ARPT REFERENCE POINT). I THOUGHT THINGS WERE GOING WELL; AND I DECIDED TO DOUBLE CHECK MY 'AFTER LNDG FLOW' CHECK AND PUT THE APU ON LINE. IN THESE COUPLE OF SECONDS CAPT ACCIDENTALLY STAYED ON ALPHA; INSTEAD OF TURNING R ON PAPA ONE. HE IMMEDIATELY STOPPED (WE WERE TAXIING SLOWLY BEFORE). WE SAW FAR UP AHEAD B737 JUST PUSHED BACK. ATC TOLD US WE MESSED UP. THE B737 WAS VERY GRACIOUS AND QUICKLY SAID THEY COULD TURN A 270 DEG TO TAXI OUT; AND DID. WE WERE THEN CLRED TO PARK. THE CAPT SAID THE SIGNAGE WAS CONFUSING; AND MESSED HIM UP; AND WISHED HE STUCK TO THE COMMERCIAL CHART. WE FLEW TO BWI 2 MORE TIMES THAT WEEK; AND I WROTE DOWN THE SIGN ON ALPHA BEHIND THE FIREHOUSE. IT IS: A; P; A; P1. THE CAPT WAS RIGHT; THE SIGN IS TOTALLY MESSED UP. IT WOULD HAVE YOU TURN LEFT FOR PAPA. VERY MESSED UP. IT SHOULD BE: A; A; P1; AND P. WHAT LED TO THIS: LOUSY FAA SIGNAGE. I DON'T KNOW IF WHAT GND SAID; JUST TRYING TO BE HELPFUL; HELPED LEAD US SOMEWHAT THE WRONG WAY. HE SAID; 'BASICALLY YOU JUST GO AROUND THE BACKSIDE OF THE FIREHOUSE.' JUST LIKE THE FAA SIGN WAS POINTING. I WISHED I WAITED 4 SECONDS MORE TO DO MY SECOND AFTER LNDG FLOW; TO HELP BACK UP THE CAPT WITH MY COMMERCIAL CHART PAGE ON OUR TAXI IN; AT THAT CONFUSING INTERSECTION. I HAD UP TO THAT POINT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT HE HAS BEEN BACK NUMEROUS TIMES SINCE THE INCIDENT AND VERIFIES THAT THE SIGNAGE HAS NOT BEEN CORRECTED AND SHOWS TXWY P TO ONE DIRECTION ONLY.