How to get to Istanbul airport by Havaist bus?

Another route option: walk along Istiklal Street to Tünel Square (near Şişhane metro), take funicular F2 down to Karaköy station, transfer to tram T1 toward Bağcılar and ride one stop across the Galata Bridge to Sirkeci. Alternative: take M2 from Şişhane to the terminus Yenikapı and transfer to Marmaray to reach Sirkeci.

Another way to reach Sabiha Gökçen airport: take the metro to Yenikapı, transfer to the M2 line to Taksim, then catch a bus from Taksim directly to Sabiha Gökçen.

Alternative route to Sabiha Gökçen airport (relevant given the M4 derailment near Bostancı): take Marmaray from Yenikapı or Sirkeci station (Fatih side) to Ayrılık Çeşmesi station on the Asian side, then transfer directly at the same station to M4 metro and ride to the final Sabiha Gökçen Havalimanı stop.

From the Kadıköy side (Asian part): take the metro to the final Kadıköy station, then catch a ferry to Eminönü, and from there take tram T1 — a quick and easy way to reach the tram route leading to the Havaist buses.

Metro line M4 between Kadıköy and Sabiha Gökçen airport derailed near Bostancı — this may affect routes to the airport from the Asian side of Istanbul.

If departing from Şişhane, check metro availability — during the incident some lines were disrupted. The Marmaray commuter rail continued operating normally.

From the historic center, take tram T1 and get off after 2 stops at the funicular, ride up to Taksim Square, then walk down the left side for about 4 minutes — Havaist buses are parked in a side street on the left. Ask locals for 'bus Havalimanı' (airport bus).