It is important when you travel as much as I do to always financial options.  My job could require that I leave the state tomorrow with no notice.  When that happens, I simply acquire some quick cash.  It would not be safe for me to head out on the road with empty pockets.  Too many times I have ended up in a jam where finances had to be readily available.  You never know when a flat tire might occur or an unexpected break down could leave you needing a hotel room.  The unexpected trips do not faze me, but I never intend to be caught without a way to make necessary purchases.