I go down Dean St. almost every morning on my commute. Thanks for the warning.
Several streets that intersect and run just south of Atlantic Ave. also have years worth of nasty buildup, particularly the ones where there's a gas station/car wash on the corners. Found this out the hard way too, only I was on blades, and it really affects the urethane wheels. Seen this on Vanderbilt all the way down to Grand st. Washington St. is pretty clean though.