Even if one chooses to vacation in their own "backyard", there are still plenty of perils out on the highway. Safety and security are a primary concern especially when traveling with children and older loved ones. Clearly the first step is to make sure the family vehicle is in top condition, have a good mechanic give it a full inspection.
Make sure the tires, belts, and hoses are in good condition. These and other rubber and plastic items under the hood tend to fail, even on newer vehicles. Be sure to also check the battery and fluid levels. Back in the trunk make sure the spare tire has air, it is a common mistake to forget this. Make sure the jack and lug-wrench are there as well. It is also a good idea to bring a couple of extra gallons of water and a roll of duct tape (the universal repair tool). A flash light and "swiss army" knife is also a good idea.
Be sure to bring plenty of drinking water and dry foods such as granola bars and trail mix. Some blankets and coats are good especially in the spring and early fall when temperatures can be erratic. You will need extra prescription medications as well. Mountain highways often close because of freak storms or fog, don't be stranded without them.
Before "hitting the road" see about buying a hand-held CB radio. Depending where you plan to travel, Many areas still are without cell service, especially out west. Truckers use channel 19 for the most part, the highway patrol is usually down on channel 9. Depending what roads you plan to travel, theres usually a trucker on them willing to help. Don't be afraid to call out for help or directions if needed, truckers are a valuable resource for road information such as accidents or bad weather.
Another great item is a satellite radio, there is nothing like traveling state to state listening to your favorite programs, and not having to constantly fiddle with the receiver. You can even listen to the weather channel if need be.
Just remember to pre-plan your trip and route, then check it online. Search for areas of bad weather and construction delays. Remember that the difference between mountain and low-lying weather can be like the difference between summer and winter.
I guess I could have wrote a laundry list, like the Boy Scout motto, "be prepared". These are just a few suggestions to get you started.
Just one last thing, don't forget that MAP!
Have a Great Ride!