Iowa highway officials have plan to install more median barriers along the interstate system.
That includes a stretch of Interstate 80 in Jasper County where seven people were killed and six others were injured in two head-on crashes last weekend.
The transportation department has been installing high-tension cable barriers in interstate medians for several years.
Officials decided to expand the program in 2007 after inspecting a three-mile stretch of Interstate 35 near Ankeny after winter storms
The barriers are now along I-35 between Des Moines and Ames.
The agency plans to install barriers along I-80 between Des Moines and Davenport in the coming years, and on Interstate 380 in Cedar Rapids next year.
The cost is about $65,000 per mile.