Travel has been an adventure again today on Iowa roadways. Sergeant Robert Hansen of the Iowa Highway Patrol has been monitoring the situation.Hansen says between 50-100 percent of the roads across Iowa are snow or ice-covered. Hansen says a mixture of winter weather caused the problems.Interstate 80 east of Grinnell was closed for several hours today after several semis jackknifed. Hansen says no injuries have yet been reported.Hansen says things aren’t expected to get much better this evening. The Patrol’s road report issued at 3 p.m. said travel is not recommended for Interstate 29 south, Interstate 80 west and highways in southwest Iowa. The Iowa Department of Transportation says it is getting low on salt to treat the state’s roadways. The D-O-T Winter Operations Manager says they may have to go to a plan that would reduce the amount of salt they use to keep from running out.