If you have a small breed that weighs less than 30 lbs., a dog car seat can give them a comfortable place where they can feel safe on the journey. This can help prevent them from wandering around the car or sitting on your lap and interfering with your driving. Larger breeds may not need car seats, as they can already see out the window, but can benefit from dog car seat belts and harnesses, which help keep them secure in case of an accident, just as they do for people.