That being said, it's important for cabbies to know how to navigate these neighborhoods. Housing projects break up streets like Butler and Warren, while the Gowanus Canal breaks up every street from Douglass to below 9th. Only 3rd and 9th Streets cross the canal both directions, while Union and Carroll cross it eastbound only. For example, you pick up a passenger on Fourth Avenue and Bergen. They're going to Union and Bond. Your instinct may be to head down Fourth and right on Union, but even though Union is a two-way street east of Third, not so to the west of that. You're best off staying on Bergen to Hoyt and taking that down to Union. Once you make the left unto Union, there's Bond! Study the area on a street map for a few minutes. And know what BoCoCa stands for: Boerum Hill/Cobble Hill/Carroll Gardens.