|Quoting SCQ83 (Reply 43):|
don't think habits are so different in many parts of America (particularly in some of Emirates' largest markets). Countries such as Belgium or Luxembourg (I think this is substantially different in NL due to tax/policy issues) have some of the highest ownership car rates in the world (on par with the US if not higher). Granted, motorways in Benelux are usually jammed, but that's the same in the Northeast US or in urban California...
The US being such a large country, it is true (and my mistake) that it depends on which region you talk about.
No-one in his right mind would drive from DC to Philadelphia to Catch a flight. Traffic is just too unpredictable. In Northern Europe for a similar distance people will not only face the same traffic, they will also will have high oil prices to swallow.
Car ownership in Europe though is not quite at the level of the US luckily though! (http://en.wikipedia.org/wiki/List_of_countries_by_vehicles_per_capita)
But yes in the Boston to Washington Area, you have 6 main long-haul international airports (Boston, Newark, JFK, Philadelphia, Baltimore and Dulles), in a similar corridor with similar densities of population , ie Amsterdam - London - Paris triangle, we have 6 major airports as well (Amsterdam, Brussels, London Heathrow, London Gatwick, Paris Charles-De-Gaulle and Paris-Orly)
This is not a scientific analysis but shows that basically with high population densities and high congestion, there is enough demand for multiple airports.