While it is technically possible to visit both the San Diego Zoo and the San Diego Zoo Safari Park in one day, it would be a very ambitious undertaking and may not allow for enough time to fully enjoy both attractions.
The two parks are located about 35 miles apart and driving between them can take up to an hour depending on traffic. Additionally, both parks are quite large and offer a wide variety of exhibits, animal encounters, shows, and activities that can take several hours to explore.
Visiting both parks in one day would require careful planning and time management, and it's recommended that visitors prioritize which exhibits and experiences they want to see most at each park. It's also important to consider the time spent traveling between the parks and the energy required to navigate each park's extensive grounds.
If you only have one day to visit the San Diego area, it may be best to choose one park to focus on and fully enjoy the experience rather than trying to rush through both in one day. Alternatively, if you have more time to spend in San Diego, consider visiting each park on separate days to fully appreciate all that they have to offer.