West Rock Ave used to be a shortcut from Whalley Ave to Chapel St/Rte 34 until the city counted cars and then put up a number of Stop signs. Full stops slow cars.
Chapel St at Yale Ave is a major straight shot to Forest Rd and then on to Woodbridge. (Recognizing this, the city already put those traffic calming islands further up.) The added issue at Chapel St/Yale Ave is the blind spots to the drivers right when on Yale because of the angle of the intersection, Yale U fencing, and a corner house on a little bit of a hill.