Date: 201401
Local time of day: 1201-1800
Location: CMH.Airport, OH
Flight conditions: IMC
Weather elements / visibility: Rain
Light: Dusk
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
ATC / advisory: Ground CMH; Tower CMH
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Human factors: Situational Awareness; Confusion; Communication Breakdown
Second reporter function: Captain; Pilot Flying
Anomaly: Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: In-flight; Taxi
Result: Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Contributing factors: Airport; Chart Or Publication; Procedure
Primary problem: Ambiguous

Narrative: The Captain briefed and flew ILS to [Runway] 28L at CHM. Weather was 1;000 FT overcast in rain at dusk. While decelerating after touchdown Tower said to; 'Turn right on Charlie 7 high speed and contact Ground.' At approximately 50 KTS we exited on the high speed and I looked down to tune in Ground frequency. Approximately 150 FT into the high-speed the Captain stopped aircraft due to orange chalks crossing taxiway. It was discovered that the high-speed taxiway we were on was actually C6; which is NOT depicted on our 10-9 page. Unable to turn around we requested a tug to push us back onto the runway and taxied to the gate without incident. Although the NOTAMs stated that there were numerous taxiways under construction; no specifics were listed. Given that standard practice after landing is to exit the runway on the first available taxiway; nothing seemed unusual about Tower's directions to 'exit the high speed and contact Ground.' Since there is ONLY ONE high speed depicted on our Airport Diagram nothing seemed unusual; until we saw the barricades. While the obvious conclusion is that we failed to follow the specific instructions of the Tower by exiting the C7 high speed and not C6; my concern is that this could very easily happen again for the following reasons: 1) First; and foremost; this high-speed taxiway is not even depicted on the 10-9 page. While there are gray 'X's around; they don't give a good idea of what is actually there. There is no dirt or obvious signs of construction; rather a completed high-speed taxiway system that looks exactly like any other. We even specifically briefed a right hand turn off on the high speed. 2) We landed at dusk; in the rain with both wipers going continuously. Tower gave us instructions while we were decelerating; verifying speedbrakes and reverser deployment and making required speed callouts. While we both heard the general instructions we did not perceive that he was issuing very specific routing. And having easily slowed to normal taxi speed we just did what we do everyday; took the next available high-speed taxiway off the runway. 3) There were no obvious barriers preventing us from turning onto a closed taxiway. If fact; the tail of the aircraft was completely clear of the runway before we encountered the 6 foot tall chalks crossing the taxiway. Reduced visibility; during a rain shower at dusk; made it hard to see any obstructions at all. Had it been daylight we might have seen their orange color in the distance or at night their flashing lights. As it was; we felt fortunate to have been proceeding slowly enough to react in time prevent us from running over them altogether. 4) This was my first time ever to this field and I have not encountered anything like this before. My feeling is that the Tower Controller could have helped prevent the situation by using verbiage such as: 'the 2nd high- speed' or 'continue down to the C7 high-speed;' etc. We often times are issued instructions during high-speed rollout and have to put responding on hold until we've got things satisfactorily under control. It is an obvious time of distraction for pilots to receive specific instructions to commit to memory. If one is extremely familiar with the standard taxi routing of a particular airport it's normally not a problem. But in our case; what seemed routine; actually became very confusing. This is not to shift blame to anyone else; only to prevent a similar occurrence from happening to the next unsuspecting crew unfamiliar with the particular nuances of this airport.


Second narrative: This was a landing in the rain around dusk; which made the visibility very poor. Taxiway C6 is not depicted on the Jepp plate and was not NOTAMed closed or listed as closed on the ATIS. The only high speed taxiway on the Jepp 10-9 page is for C7. I assumed after landing and rolling down the runway that this was the only high speed exit available; and did not see the chalks across the taxiway because they were well back from Runway 28L (these chalks were about 140 feet from runway edge). It was not dark enough to see the portable lights on the chalks; or light enough outside to see the chalks from the runway. After tug pushed us back; we taxied to the gate.Taller; more visible barricades and moving them closer to runway would help. Better information from ATIS or ATC tower that the only high speed open was C7. The high speed C6 was not depicted on Jepp 10-9; therefore I was only expecting to see one high speed exit.


Synopsis: A flight landed on CMH Runway 28L at dusk in rain and exited onto a closed taxiway after being cleared to exit on the next Taxiway C7. The barricades were not seen until they were on the closed taxiway well clear of the runway.