A Salem County man was killed in asingle-vehicle motorcycle crash on Thursday afternoon, according to the New Jersey State Police. William K. Greenwood Jr., 68, of Elmer, was riding his motorcycle south on Route 635/Cohansey Friesburg Road near Alloway Friesburg Road in Alloway shortly after 2 p.m. when he traveled off the road to the right and into a ditch. Greenwood was thrown from the motorcycle and struck a concrete culvert, police said. He was pronounced dead at the scene. The crash remains under investigation. Our journalism needs your support. Please subscribe today to NJ.com. Matt Gray…