Following an earlier comment which indicated that this could be a typo for a "roach colony", @msh210 was able to confirm that this 1980 edition of the book indeed had a "roach colony" where the 1987 edition mentioned by the OP has the "road colony".
Three pages down the story, we get an independent clue (preserved in the 1987 edition):
On the way back to the car, we stopped at a Broadway supermarket. I bought roach spray, rat repellent, soap, [etc.]
By this time, the protagonist is no longer going to stay in the exact place with the "road colony", but rather in another shabby place nearby. It's implied that the overall experience from surveying the neighborhood contributed to what the protagonist chose to purchase for survival.
The fact that the "road colony" is described as vertical helps decide between the relevance of the roach spray versus the rat repellent.
Finally, the problematic word appears at the end of a line, on a verso page, at least in the 1987 edition. Conceivably, the book opens with those trailing letters starting to bend away toward the spine also in the 1980 edition. This makes me think that we are looking at an OCR error where a skewed/cutaway "ch" ended up recognized as a "d" while preparing the 1987 edition.