No matter how spontaneous you may be, a little planning always makes good sense when you're headed out on vacation. You want to have some idea of where you're going and how long you'll be there.
First, you need to choose a destination. There may be an area that you've been thinking about visiting for some time, or you may have no clue where you want to drive.
A lot of Web sites -- including Road Trip America and Rand McNally -- offer free road trip routes to help you plan your drive. You just click on the region you want to visit, and these sites will give you several different driving options, including trip times, maps and attractions along the way. Use these sites, as well as other general travel Web sites and books, to map out your trip. By plotting out your trip ahead of time, you'll know exactly how long it will take you to get there, see the sights and then get back. This is especially important if you only have a set number of days to travel.
Figure out how far you're going to drive each day and which places you absolutely have to see. Add to your list a few back-up destinations, in case you have some extra time on your hands, and know which places you'd be willing to cut from your list if you get stuck in traffic or run behind schedule.