Taking the bus to Animal Kingdom

First trip to Disney - The book says if you’re going to Animal Kingdom before the park opens use Disney transportation, rather than your own car. We have a breakfast reservation before the park opens. Why is it better to take Disney’s transportation? We are staying at Boardwalk.

Depending on what issue of the guide you have, it is my understanding the AK’s parking lot used to not open early. However, that, apparently is no longer an issue:

I believe @cjandres is correct. I would take my car.