The shelf life of bread depends on a variety of factors, such as the best by date, the preparation method and how it was stored. Bread is made of flour, water and yeast. Because of its relatively low cost and high calorie density, bread is one of the most popular food staples in the world.
You should always carry these items in your car, but you should check your pack before you embark on a long trip. There are many more items that you can add to your vehicle that can be a huge aid in a pinch, but these are the basics. A set of jumper cables or a fully charged jumper pack.
Think of your health before the trip, during it and afterwards. Wash your hands often when traveling. This includes before and after getting on the plane, and as soon as you complete your time in the airport. Since liquids can't travel on most airlines you can take a pack of anti-bacterial wet wipes.