Side by side double strollers are WIDE.
My nephew has a double which has one seat in front of the other instead of side by side. They returned the side by side after an airport drill with the twins and got the front and back narrow style instead.
http://www.amazon.com/InStep-Safari-...ouble+stroller
Trying to maneuver two separate strollers and rolling carry-ons around an airport during summer family vacation travels is only suitable for comedy sketches.
The WIDE strollers can be challenging to maneuver in older cities or cities in Asia as well.