Date: 201411
Location: ZZZ.Airport, US
Weather elements / visibility: Cloudy
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Taxi
ATC / advisory: Ground ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Workload; Time Pressure; Situational Awareness; Confusion
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Detector: Person Air Traffic Control; Person Flight Crew
When detected: Taxi
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Contributing factors: Procedure; Human Factors; Airport; Weather
Primary problem: Ambiguous

Narrative: This was a classic example of keeping one's head securely lodged in their rear end instead of having it on a swivel in order to maintain a modicum of situational awareness.  The most immediate threat at that time were the aircraft crossing runway 9L after landing on 9R and I should have been more concerned with that area.At Spot X we were given 'Behind the Airbus; Taxi to Runway 9L via… Taxiway K; hold short of taxiway N.'  As we turned off onto K I quickly looked at the Airport Diagram and noted that it was not far to N.  For some reason I believed that it was the second taxiway; not the next one coming up.  Due to the heavy volume Ground was utilizing a Tower sequencing frequency and I noted that the First Officer was loading this frequency.  At the same time I was also watching the Airbus ahead of us (not told to hold short of N) and the activity on the taxiway to our right; on taxiway J.  I also observed that traffic was being sequenced for Runway 9L on taxiways; K; J; and W.  Suddenly the First Officer pointed out that there was an aircraft immediately to our left on a crossing taxiway.  I noticed the aircraft and then realized via the taxiway signs that the nose of our aircraft had already penetrated the N taxiway by about 10 feet.  The 170 crossing runway 9L on N had stopped; and its tail was still over Runway 9L.   I started to come to a stop but then observed an aircraft that was in position for takeoff on 9L and elected to add thrust and get out of the way so that the 170 could clear the runway in case the aircraft on the runway should start its takeoff roll.  I also told the First Officer to advise Ground that we were passing through taxiway N; but by then ground was already querying us.  We were told to continue on K and hold short of taxiway T; which was complied with.  The rest of the flight was uneventful.There are a few airports that we operate out of that have less than ideal ground flow patterns; and taxiing for take-off on runway 9L at ZZZ easily falls into this category.   It is of utmost importance to be cognizant of these situations and act accordingly.


Second narrative: I think we were not used to the taxi instructions of an east operation because it is rare at ZZZ; plus we were already late after sitting around for 3 hours; plus I should have been heads up watching.


Synopsis: An air carrier crew on Taxiway K for Runway 9L was told to hold short of Taxiway N but inadvertently entered Taxiway N preventing an aircraft from exiting Runway 9L. So realizing their error; they crossed Taxiway N to permit the other aircraft to exit the Runway.