Credit to EXPEDIA Europe's Airports

This infographic made by Expedia displays the distance from the airport to the city center, the average traffic density and tips & tricks for a comfortable travel in Europe.

The busiest European airports by average passenger traffic density are:

1. London Heathrow

2. Paris Charles-de-Gaulle

3. Madrid Barajas Airport

4. Amsterdam Airport Schiphol

5. Roma Aeroporto di Fiumicino

6. Copenhangen Airportkastrup

7. Oslo Airport Gardemoen

8. Viena Schwechat

9. Stockholm Arlanda Airport

10. Brussel National

11. Dublin Airport

12. Berlin Tegel 

Have you ever been in one of these airports? 

Are there any special rules?

Which one do you consider the most friendly of all?