Maryland State Police say all lanes of northbound I-270 north of New Design Road are closed on Thursday morning. Lanes will be closed between three and four hours to remove and replace a sign damage in a car accident at 5:40 a.m. Thursday, say state police. A Chevrolet Malibu went off of the road and struck a pole holding an overhead sign, say police. The driver was injured and transported by ambulance to Meritus Medical Center in Hagerstown, according to police. There is no word on his or her current condition.