Hi, I wrote an article about this for the Daily News, which you can read here: http://www.philly.com/philly/columnists/city_howl/20120201_City_Howl_Help_Desk__TO_YOU_AND_THE_LAW_IT_S_A_TRUCK__BUT_TO_THE_CITY_IT_S_A_PASSED-BUCK.html

But essentially, since there's a no truck parking sign, the police will come to ticket the truck if you call 911 and report it. You can email me at howl@phillynews.com if you need anything else!