Not sure if this applies to what is going on in your case, but one thing that changed about that most recent street rule is that it gives priority to placement of parking and bike lanes, and then uses the remaining street width to give as many lanes as possible. If there is leftover space, it inserts that as a slim piece of concrete, rather than widening the lanes to fit (I think it inserts this between the bike lanes and the street, or maybe in the gutter - can't remember without looking back into the code). This wasn't necessarily the best solution so it might change in the next iteration. Input for street rules? This case, or other needs?