I've always wondered about the jog in Addison at Oriole and I think you might just have answered my question. Thank you! I love this site! I believe it has to do with the boundary line of the suburb of Elmwood Park as it begins at Oriole Ave. on the south side of Belmont. You'll also notice that the streets west of Oriole and south of Belmont in Elmwood Park are numbered. 76th Ave. instead of Oriole, 77th Ct. instead of Ozark and so on but north of Belmont they retain their Chicago "O" names. You can also see that Addison Street takes a slight jog to the north at Oriole possibly to compensate for the slight shift in road size at Belmont and thus retaining the standard Chicago block and lot sizes. My grandfather built a house on Oriole Ave. just north of School St. when that area was still considered part of Leyden Township but was being newly annexed to Chicago.