If you travel to Hanoi on a budget or simply want to be like local people, the new public bus route Hanoi - Noi Bai airport is available, cheap, convenient and comfortable.
The ticket is just 30.000 VND per way (around US $ 1.3 USD) while airport taxi is around US$ 15-20 per way. It is 33km from the airport to the last stop at Le Duan Street, the bus has eight stops and takes you 55 minutes.
The bus offers free wifi service and can carry 80 passengers per leg.
Hanoi Station between 5:05 am and 9:40 pm
Noi Bai airport between 6:18 am and 10:58 pm.