Saga City has large roads to support domestic Zoids. These two-lane roads can support Zoids as large as an Ankyrox, with some height limitations due to human walkways that run above them. Most Zoids pictured in the city however are quite small, such as Raptors and Scorpears, so this isn't much of an issue.
The Empire was pursuing Sally Land, the granddaughter of renowned scientist Walter Bowman. They followed her to the outskirts of Saga City, where they ran into Leo and Buzz. When Leo and his Liger attempted to drive them away, the imperial forces aggressively countered, nearly destroying the Liger. It was thanks to the pendant that Sally was carrying, which triggered an evolutionary state in the Liger, that the battle came to an end. Afterwards, Leo and Buzz decided to leave Saga City to assist Sally on her journey.