I-580, I-238, and I-880 are all well-known routes of travel throughout the Castro Valley area. While a lot of people rely on public transportation, such as AC Transit and BART, there are still a lot of cars found on the road.
Of course, the more cars you find on the road, the higher the likelihood of there being some type of accident. The last thing you want is to be caught out there without reliable auto insurance. If this is a concern for you then you might visit Castro Valley Insurance Rates.