Two of Ames' busiest streets will see extensive construction this summer. Civil engineer Mark Gansen says widening work on S. Duff Ave. from Jewell Dr. to Ken Maril Rd. will start in about three weeks and close the street for at least 30 days. He says a detour will involve Interstate 35. Gansen also says the city will continue rebuilding 13th St. This year's work moves in phases from east of the Union Pacific railroad tracks and to Harding Ave. He says the city wants to have the stretch from the tracks to Northwestern Ave. completed before the start of classes in the Ames School District. Gansen says timing for all the work depends on weather, which has already pushed back some early projects by a couple of weeks.