Hotrod, bicycles would be a huge asset, I would think. They can fit in or on any vehicle if you have the right accessories. They give you an additional option when your vehicle breaks down, runs out of gas, gets stuck in mud or gridlocked in a stand-still traffic jam that continues for miles up the road.
Regarding the latter scenario, suppose you and your wife are stuck trying to evacuate an area, and the road you're on is backed up for miles and miles, and the traffic has been at a stand-still for hours now--not even a crawl. People here and there are already running out of gas just sitting still, letting their engines run at idle. Tempers are flaring. Violence seems impending. Panic is setting in as people start to get desperate. You and wife have the vehicle loaded down with supplies, food, water, clothes and valuables (guns, photo albums, jewelry, your KNIFE COLLECTION you've spent untold time & money on, etc.). Sooner or later, EVERYONE (including you) will be out of gas, but tempers will have progressed into fights, looting and large scale pandemonium on the road long before then, and you don't want to be in the middle of it.
You can leave on the bikes, but you'd be forced to leave most of your supplies, valuables, and other belongings behind (to be looted, for certain; there's no coming back for it later). You could distance yourselves from the overcrowded roads but how many days could you go without your supplies that you had to leave behind in the vehicle? Or you could stay with your vehicle and try to guard it, your belongings, and yourselves from your fellow travellers (which will mean you and your wife/gf taking shifts when night falls, and each day will be more desperate and dangerous than the one before)...and to what end? In the hopes that traffic will eventually begin moving again, and that the roads will soon clear up? Or that maybe FEMA will send fuel trucks up and down the roads to refuel people's tanks?
Obviously, the reason for the evacuation is usuall going to be time critical, such as a nearby nuclear plant reactor leak, or a hurricane, in which case you know time is against you.
