Date: 201309
Local time of day: 0001-0600
Location: SAV.Airport, GA
Flight conditions: VMC
Light: Dawn
Aircraft: Medium Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: CTAF SAV
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Human factors: Situational Awareness; Confusion
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: In-flight; Taxi
Result: General None Reported / Taken
Contributing factors: Chart Or Publication; Procedure
Primary problem: Chart Or Publication

Narrative: We started taxiing out in SAV before the Tower was open. The wind was calm; and two airplanes were taxiing to Runway 10. To get to Runway 10 from the terminal you take Taxiway F to Taxiway E normally; so that is what all three airplanes did. When you turn onto Taxiway E from Taxiway F there are red lights across the taxiway indicating a closure; so all three airplanes did the same thing; stop. I assume the first two airplanes did the same thing as we did when they stopped. Check their 10-7 pages and the NOTAMs; nothing about a taxiway closure in either. Both [Air Carriers ahead of us] continued down taxiway to Runway 10 for takeoff; which we now know is a closed taxiway from E1 to the west end of Runway 10. Unfortunately; after consulting our 10-7 pages and the NOTAMs; we did the same thing. There is a sign on the side of the taxiway next to the red closure lights that says ILS critical area closed when the Tower is closed between 12:00 and 0600; nothing about the taxiway actually being closed. I assume both airplanes in front of us believed that the ILS critical area should be open since it was severe VFR just like we did. Once we finally looked over our SAV 10-9 page once we were airborne; we saw the little boxed note that talks about the taxiway closure up by the terminal. We did wait to taxi down the end of the runway until after we had been released by Center; though.Obviously there is an issue. Three airplanes did the same thing and it wasn't because we just wanted to taxi down a closed taxiway; it is because there is some confusion with the facility. I believe the sign on the side of the taxiway needs to say the same thing as the boxed note on the 10-9 page; that the taxiway is closed not just the ILS critical area. Errors we made: Not looking at all the boxed notes on the 10-9 page. Following the pack; we talked about back taxiing then just decided to do what the other airplanes had already done.I think the boxed note on the 10-9 page should also be in our 10-7 pages.


Second narrative: Taxing out in SAV with the Tower closed and before dawn to Runway 10 via Taxiway F and E. Making the turn onto Taxiway Echo; we noticed red lights across the taxiway. They were associated with a yellow information sign that said; 'Taxiway Echo ILS critical area closed when Tower closed.' Since it was VMC; and two other air carrier aircraft taxied past it; we decided it was okay to continue onto the rest of the taxiway. Once past the line we noticed that there were no taxiway edge lights; which raised some red flags. We continued and once in flight; I looked closer at the 10-9 page. There was a note indicating that Taxiway Echo was closed past the critical area when Tower was closed. I did reference this on the ground; but I missed it. It is very confusing signage and notations on the 10-9 page. The 10-9 says the taxiway is closed past the ILS critical area when Tower is closed; but the sign makes it seem that it is only closed when the weather is below that which the ILS critical area is protected. We were unsure which they wanted. I think this should be reviewed as it did; and probably will continue; to cause confusion in the future. Since two other aircraft in front of us did the same thing; there is obviously an issue here.The threats were that the field was uncontrolled; it was dark; and it was very early in the morning. There may have been an error of taxing on a closed taxiway; but we are unsure if this is the case due to confusing and conflicting information.


Synopsis: The SAV Airport Diagram Chart notes that Runway 1 and 10 ILS critical areas are closed when the Tower is closed but the restrictions are easily overlooked and should be described on other publications also.