Real Dictionary

street smarts
plural noun: You can use street smarts to refer to the skills and intelligence people need to be successful in difficult situations, especially in a city.

street smarts in American English
cunning or shrewdness needed to live in, or to deal with people living in, an urban environment characterized by poverty, crime, etc.
plural noun: shrewd awareness of how to survive or succeed in any situation, esp. as a result of living or working in a difficult environment, as a city ghetto neighborhood

street smarts in British English
plural noun: the skills and cunning necessary for surviving in an urban, poor and often criminal environment