B737-700
Flight Crew Last 90 Days 196; Flight Crew Type 6000
Confusion; Other / Unknown
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors
Exited Runway 29 in EWR.  Told W2 to Y eastbound.  Diagram showed left turn off runway and straight to Y.  We saw a sign for Y in the distance.  There was no other taxiway we saw.  We went to the taxiway we thought was identified by the Y taxi sign (closest to it).  We ended up on another carrier's ramp.  Ground said we missed Y and we stopped.  He coordinated with Ramp and we continued uneventfully to the gate.  Better signage and ground markings.  We didn't see Y properly and ended up on another carrier's ramp.
B737 First Officer reports confusion after exiting Runway 29 at EWR on Taxiway W2 and being told to taxi via Y; ending up on the Terminal C east ramp. Lack of signage and taxiway markings is cited.