Buses normally need between 2h 25m and 4h 10m hours to get to Halong Bay from Noi Bai Airport. Note that the travel time is for your reference only and can depend on different factors such as traffic and weather conditions. Heavy rainfalls almost inevitably make the trip longer due to poor visibility or floods. Road and surface repairs which happen quite often, result in detours and longer travel times. Major national holidays, long weekends, or peak season periods may cause delays both in departures and arrivals – plan accordingly to avoid disappointment, especially if you have further connections and a tight schedule.
On this route, Hung Duc Quang Ninh offers the fastest service. Grouptour (Công ty du lịch quốc tế Grouptour) buses usually take the longest time to complete the journey.
Remember, though, that tickets offering the shortest travel time are normally the most expensive ones. Yet it pays to spend a bit more to ensure your bus goes direct without additional stops and uses highways instead of local roads.