Date: 201305
Local time of day: 1801-2400
Location: IAH.Airport, TX
Flight conditions: VMC
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight phase: Taxi
ATC / advisory: Ramp IAH
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Human factors: Other / Unknown; Confusion
Second reporter function: Pilot Not Flying; Captain
Anomaly: Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Became Reoriented
Contributing factors: Human Factors; Procedure; Airport
Primary problem: Human Factors

Narrative: Following push-back (we were instructed to push tail east for a 15L departure); we called Ramp for taxi clearance.  We were instructed to taxi to RB and proceed to Spot X.  Ramp Control informed us there was an inbound jet (from the RB Bridge) on RB that was giving way to us.  When the Captain noticed the inbound jet; it had already transitioned to the RC line inbound.  That area of the ramp is very dark and the signage is poor.   As a result; the Captain misjudged the location to the jet and consequently we also joined RC instead of RB.  By the time we realized our error we had taxied beyond Spot Y and were beginning to encroach upon taxiway WB.  Adding further confusion to our taxi clearance; there was also an A320 proceeding westbound on RB (possibly RA; area is very dark and difficult to tell exactly which line they were on) that we were never told anything about.  So; as we began our taxi southbound to join the RB line; the A320 was proceeding westbound towards WB.  As a result of their position on the ramp area; we assumed the line north of their position was RB.  Unfortunately; that was not the case as the line to their north turned out to be RC.  Then this same A320 joined WB northbound.  This crew continued their taxi despite our relative position to taxiway WB.  In fact; the wingtip of the A320 came within an uncomfortably close distance of the nose/flight deck area of our aircraft.   At no point did the A320 slow or stop and permit us to maneuver to a safe area.  They merely taxied off the centerline to the west and created a very dangerous situation.Poor lighting/signage in the ramp area With multiple taxi lines/call spots; in a very poorly light ramp area; and the close proximity to a  taxiway the potential for improper maneuvering is very high.  Also within that same small area; there are 3 radio frequencies (Ramp; Clearance; Ground) aircraft are required to talk to.  Depending on position and what instructions have been given to each aircraft each one could be on a separate frequency reducing area situational awareness dramatically.  Improve lighting/signage in ramp area.  Streamline the ATC process by eliminating frequency changes in small area/short distance.  Have ground support push aircraft on to the appropriate taxi line (RA; RB; RC) prior to disconnect.


Second narrative: Ramp Control cleared us to push tail east.  We started engine #1; finished the before taxi check and contacted Ramp Control.  Ramp advised us to join RB ahead of an inbound B737 already on RB; and to contact Ground at spot 2.  I lined the aircraft up on what appeared to be the same taxiway as the B737 was on.  I had actually lined the aircraft up on RC instead of RB.  I taxied over the Spot 3 number and stopped the aircraft.  I was on RC and not RB.  After reviewing the airport diagram; the B737 was just coming over the bridge at RB when I was trying to line up on the RB taxiway.  There was also an A320 approaching quickly from the left that must have been on RA. The A320 continued on RA and then passed in front of us on WB.  We called Ground at Spot 3 for taxi instructions.  We were given WB to WV to Runway 15L. Contributing factors: -Poorly lighting in this area at night. -The yellow lines are not marked very well leaving the ramp area. -Too many people to be talking to in such a small area ramp; clearance; and ground. -Next time I plan to spend more time reviewing my airport diagram. -Wait to move the aircraft until I know exactly where we are going.


Synopsis: A319 flight crew reports being confused by their taxi clearance and the Romeo taxi lines south of the west ramp at IAH.