An air carrier crew departed a PVD gate at the terminal's northeast end and taxied onto Taxiway F but their taxi route clearance began with Taxiway N. The crew could not distinguish between the two taxiways out of the gate because there were allegedly no markings.

Narrative

During taxi out from Gate at PVD; ATC issued the clearance; 'Taxi to Runway 34 via N; T and C. Hold short Runway 23 at C.' I wrote down the clearance and paused briefly before taxiing because both the First Officer and I were not immediately familiar with this route and could not quickly find taxiway signs to aid in our departure from the alleyway. I remember having trouble finding Taxiway T on the Jeppesen 10-9 page. Once I located it visually; I fixated on the transition from Taxiway T to Taxiway C thus failing to realize that I was actually using Taxiway F to join up with Taxiway T. I used an unassigned taxiway. This error is of concern because of the fact that three taxiways come together in this area which also appears to be part of the terminal ramp. While the Jeppesen 10-9 clearly designates the uncontrolled ramp at the terminal; it is not as easy to distinguish the taxiways. Taxiways F and N are not easy to see when maneuvering around the end of the terminal. Painted boxes; while existing for inbound aircraft; do not exist for aircraft departing the alleyway. Since there is little space to place upright signs designating Taxiway F to aircraft leaving the alley; surface boxes designating Taxiway F and N should be painted straight out from the northeast gates (at the terminal ramp dashed line) so that aircraft leaving the alley can quickly identify Taxiway F and N lead out lines.