Date: 201208
Local time of day: 1801-2400
Location: DEN.Airport, CO
Flight conditions: VMC
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ramp DEN
Reporter organization: Air Carrier
Reporter function: Check Pilot; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion
Anomaly: Deviation / Discrepancy - Procedural Clearance; Ground Event / Encounter Other / Unknown; Ground Excursion Ramp; Ground Incursion Taxiway
Detector: Person Ground Personnel
When detected: Taxi
Result: Flight Crew Became Reoriented
Contributing factors: Airport; Chart Or Publication; Human Factors
Primary problem: Ambiguous

Narrative: Ramp markings are very confusing and misleading on the south apron at DEN. There is ramp construction taking place on the south ramp; which requires a south taxi deviation around the construction zone. There is an airport NOTAM; but I would suggest that this NOTAM be expanded to add clarity. We entered the ramp from the east side and came in on Taxiway Alpha North and began our westbound taxi on the ramp. We were told to give way and follow an RJ that had just taxied away from the commuter terminal. Additionally; the Ramp Tower advised us of the construction ahead on the Alpha North Taxiway; and told us that we would see a yellow taxi line that would guide us around the construction zone. As we approached the construction zone; we noticed the Commuter RJ start a left turn and realized he was following the yellow line. We mistakenly followed the RJ on the same yellow line. This yellow line was a solid line and appeared to be the line that we had been told to follow. Once established on this line Ramp Control directed us away from the line we were on; stating that there is not enough room for a B777 on the purple line. It was at this point; that we realized that the yellow line we were following ran parallel to a solid purple line. Looking ahead; we saw a second solid yellow line; which was the one we were expected to be on.First a compliment to the Ramp Tower Controller who was watching us; and realized that we were not on the correct yellow line. I would suggest to Denver International Airport that they paint a different line for wide body aircraft to follow; perhaps a stripped yellow line or an alternating yellow and orange line. But listening to the original instructions to give way and follow the RJ and plan to follow the yellow line around the construction zone was very misleading. The expanded airport pages do describe the purple and green lines that are used for the ramp by smaller aircraft; however as we initially joined the solid yellow line; we did not see the purple line until we were closer to the terminal. Another suggestion would be to have ramp tell us to follow the 2nd yellow line around the construction zone. Not sure how to avoid the same mistake we made; as the markings are confusing. Perhaps sharing this information with the airport/ramp would help.




Synopsis: Confused by multiple ramp taxi lines; construction and NOTAMs; the Captain of a B777 initially followed the wrong yellow ramp taxi line that did not provide adequate safety margins. An alert Ramp Controller advised of his error.