Medium Large Transport
Flight Crew Last 90 Days 218; Flight Crew Type 7730
Other / Unknown
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors
Our taxi instructions were B; B5; P; C5; L; to 13R at DAL.  As we taxied on B; we saw the sign to P and followed it not knowing B5 was still ahead.  So; we missed B5 altogether.  The signage and instructions were confusing since P comes before B5.  ATC wanted us to stay on B until B5 and then rejoin P later.  The new taxiways are confusing around the new terminal.  A better review of the [briefing page] would have helped.  A late push didn't help.   Change P near the terminal to P1.
Air Carrier First Officer reports a taxiway incursion while attempting to taxi via B; B5; P...  B5 is missed altogether.  A new terminal; taxiways and a lack of signage were cited as factors by the reporter.