To steal from a thread on some other board because I thought it was interesting.
Logan Circle is beautiful but it's still cut off by a traffic circle. I propose making it back into a square by eliminating the traffic circle and relegating all cars to teh square bounded by vine, 18th, 20th, and race. take a look at it with google maps and see what I mean. This park could be even better than rittenhouse (or at least just as good)it's near offices, institutions, city hall, and there's potential for more development nearby development on vine, parkway22, cherry st, etc.
edit: to further that idea, geometric lines woudl be retained by a path within logan square rather than a road. westbound traffic would be fed onto the parkway both by vine st and 20th St. 20th St woudl be made two way between the parkway and market. The long term goal would be to cap 676 at least between 18th and 20th, and restore race st.