Before setting off on a driving vacation, you should:

Planning your route and understanding the layout of your final destination is crucial for a successful and safe driving vacation. Familiarizing yourself with the travel route can help you identify road conditions, construction zones, and any potential detours. Knowing the layout of your destination allows you to navigate more efficiently, locate accommodations, and find points of interest, which can enhance your overall travel experience. It prepares you for what to expect upon arrival and reduces the stress of navigating an unfamiliar area.

The other options may have some merit in different contexts, but they do not directly contribute to the foundational preparation needed for a safe trip as effectively as familiarizing yourself with the route and destination. For instance, while having emergency numbers is important, they are better kept in a location where you can access them without distraction rather than next to the steering wheel. Designating drivers can be beneficial for long trips, but it is not a fundamental step to take before setting off. Listening to music can enhance the driving experience but should not be prioritized over practical planning.