The key factor is alcohol. Over half of fatal accidents occurring on the 4th of July are alcohol-related.

Unfortunately, the danger doesn't end after the Fourth. Since the 4th of July falls on a Sunday, most Americans will have Monday off, making for a potentially explosive 3-day weekend. On Friday and Saturday, the roads will be packed with motorists heading out of town for the long weekend; on Monday, the roads will overflow again, this time with thousands of half-conscious drivers fighting nasty hangovers. In 2008, 491 people died in auto accidents during the three-day 4th of July weekend.

The best way to escape the 4th of July weekend unscathed is to avoid driving altogether. Take regional transit or celebrate at home. If you're visiting friends or relatives, make plans to spend the night. If you do plan to drive, avoid driving after 10 p.m. and get a designated driver if you plan to drink alcohol.

If your auto insurance company learns you've been busted for a DUI, your rates will skyrocket and your policy may be terminated.