大街(dà jiē) - main street, high street; the street in Mandarin

大街 (dà jiē) is the wide, busy street through the centre of a town, the nearest thing Mandarin has to the British high street. It also does duty for the street in general, in the sense of out in public: 大街上 means out where everyone can see you.

That location phrase is the one to learn whole. Chinese needs the 上 on the end, so it is 在大街上走 rather than 在大街走. The pair 大街小巷, big streets and small lanes, is the set phrase for all over town.

The trap is treating 大街 as an address. Named roads use 路 or 街 on their own, as in 南京路 or 王府井大街, and you never say 我住在大街 for I live on the main road. For the road you drove in on, use 路. 大街 describes a kind of place, not a postal line.