The Ninoy Aquino International Airport Expressway (NAIAX), signed as E6 of the Philippine expressway network, is an elevated expressway in Metro Manila, Philippines, which links the Skyway to Ninoy Aquino International Airport and Entertainment City. Traversing the cities of Pasay and Parañaque, the NAIAX runs along Andrews Avenue, Electrical Road, and NAIA Road connecting the Skyway to Ninoy Aquino Avenue, Macapagal Boulevard, New Seaside Drive and the Manila–Cavite Expressway. The expressway is the first airport expressway in the Philippines. It opened in September 2016. It traverses the cities of Pasay and Parañaque. Route description From the Sales Interchange (NAIA Exit) of Skyway, the expressway heads to the southwest and runs along Sales Road across Villamor Airbase and Newport City. It then curves to the northwest on Andrews Avenue towards the entrance to NAIA Terminal 3 and continues along the northern perimeter of the airport towards Electrical Road near NAIA Terminal 4. From here, it makes a turn to the south and runs along Parañaque River, parallel to Domestic Road on the east towards the NAIA Road junction. From this junction, the expressway branches into two, with one traversing eastwards to NAIA Terminals 1 and 2, while the other continues westwards to Entertainment City and the Manila–Cavite Expressway. Features The expressway is operated and maintained by Skyway Operations & Maintenance Corporation (SOMCo), the same company that operates Skyway, while its concession holder is SMC NAIAX Corporation (formerly Vertex Tollways Development, Inc.); both companies are subsidiaries of San Miguel Corporation. Lanes Prior to the opening of the Skyway expansion project (by eliminating shoulders and shrinking the median) in 2020 that resulted in a grand total of 7 lanes, and due to the lack of right of way available for the project, NAIAX is the second expressway that does not have a shoulder, after North Luzon Expressway between Balintawak to Balagtas (Tabang Interchange) following widening to four lanes as a heavily traveled segment, and the first expressway having a narrow concrete barrier as median. Even though SMC claims that NAIAX is a 4-lane elevated expressway, in fact, SMC via its subsidiary, Vertex Tollways Development, has built 5 to 7 lanes on the expressway without shoulders and with a narrow median barrier, with the configurations listed below. 5-lane zones 2 lanes to Macapagal Boulevard/NAIA Interchange (catering to motorist to/from NAIA Terminal 1 and 2) and 3 lanes to Skyway for (1) half part of