February 2, 2015 5:30 am Roads Prove Slippery as Crews Clear Jackknifed Tractor-Trailer NBC10’s Matt DeLucia is in StormForce10 checking out road conditions in Lehigh County where crews are working to clear a jackknifed tractor-trailer. US & World Videos 25:15 WATCH: Mayor Cherelle Parker announces all city workers will return to office full-time this summer 1:55 Penn students graduate amid extra security after an academic year full of unrest 11:16 Another campus protest in Philly: The Lineup 0:47 What advice did Keith Jones give to Arcadia University's graduating class? ‘Be bold' 1:11 Cabrini University graduates final class with Kylie Kelce addressing commencement