Date: 201507
Local time of day: 0601-1200
Location: SFO.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground SFO
Reporter organization: Military
Reporter function: First Officer; Pilot Not Flying
Human factors: Confusion; Human-Machine Interface
Second reporter function: Pilot Flying; Captain
Anomaly: Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: Taxi
Result: General None Reported / Taken
Contributing factors: Human Factors; Airport
Primary problem: Airport

Narrative: Landed Runway 28R SFO and instructed to turn left on Taxiway E; cross Runway 28L; and contact Ground Control. On Taxiway E; Ground Control instructed to turn left on to Taxiway B to Taxiway F1 and join Taxiway A to the gate and go in front of another carrier's aircraft that was on Taxiway A. The Captain and I discussed the taxi clearance and agreed on the instructions. I had the 10-9 page displayed on the EFB and assisted the Captain during taxi operations. I made sure we were well clear of the other aircraft and transitioned onto Taxiway A from Taxiway B and Taxiway F1. Taxiway F1 was difficult to identify with ground markings/signage. We remained well clear of the other carrier and cut slightly from Taxiway B to F1 and then joined Taxiway A.  Ground markings/paintings/signage is very poor and confusing in this area. The depicted boxed inset on the 10-9 page is not representative of what is visible from the taxiways. Improved signage and ground paintings/markings would help alleviate future incidents.


Second narrative: Landed 28R at SFO and was told to turn left on Taxiway E; cross 28L; and contact Ground. On Taxiway E; Ground instructed us to turn left on Taxiway B to Taxiway F1 and join Taxiway A to the gate. I commented to the FO 'let's be heads up' because it is (for me) always difficult and confusing to locate Taxiway F1. Even with the 10-9 displayed and the boxed inset of that intersection; it is confusing.I taxied on Taxiway B to what I saw as Taxiway F1 and started a slight right turn to Taxiway A. The pavement is poorly painted (hard to see) and I didn't see the sign for Taxiway F1 to Taxiway A. There was another carrier's plane parked waiting for taxi and we both saw and acknowledged his position; which we taxied by with no incident and my FO called out his position from us.In retrospect; I cut off Taxiway B prematurely and headed toward F1. I hit F1 and continued to Taxiway A to the gate with no incident or any calls from Ground or any other aircraft. If you look closely at the inset on the SFO 10-9; I do not see the taxiway between A and B labeled so I feel the signs and ground markings and paint need to be enhanced and made much more identifiable. As a sided note; when taxiing to 1L for departure; there is black concrete and fresh paint; ground markings and ample signs; which is much more identifiable and less confusing.


Synopsis: Air carrier flight crew report being cleared to taxi via Taxiways B; F1 and A to the gate; but were not sure that they used taxiway F1 to transition to A. Signage is reportedly lacking and the depicted boxed inset on the 10-9 page is not representative of what is visible from the taxiways.