道

How it works

を (object) marks 道(みち) (road) as the thing being crossed, and it sits right before the verb. The verb 渡る(わたる) (cross) takes its volitional form 渡ろう(わたろう) (let's cross), the casual "let's…" ending that suggests doing something together. No polite です (is) or ます (polite) here, so it sounds relaxed and friendly.