Green’s Dictionary of Slang

(US) the street, the pavement.

1941		D. Burley N.Y. Amsterdam News 8 Feb. 20: I’d soon be knocking a duster down the cruncher one of these early tints.
1944		D. Burley Orig. Hbk of Harlem Jive 12: I nixes my pad, drops the twister on the keep, and collars a light broom down the cruncher to the lushpad on the three pointer. [Ibid.] 38: You’re slicing your chops about these fine young hens been tipping down the crunching straight in the cool of the evening.
1946		Mezzrow & Wolfe Really the Blues 219: Hey Jim, your main saw on the hitch just trailed down the cruncher about tick twenty.