IA SF378

Increases Iowa's default speed limit for all vehicular traffic from 55 MPH to 60 MPH, applicable when no other speed restriction is posted

Does not change existing specific speed limits for cattle guards (15 MPH), business districts (20 MPH), residential/school districts (25 MPH), state parks (35 MPH), suburban districts (45 MPH), interstate highways (70 MPH), or other designated areas

Allows agencies with jurisdiction over affected highways to use temporary nonpermanent overlays or stickers approved by the Department of Transportation on existing speed limit signs until signs are replaced on their regular schedule

Does not modify the 34-56 MPH speed limit range used by DOT when determining whether to count minor speeding violations (10 MPH or less over) toward license suspension

Maintains existing penalty structure for speeding violations, with fines ranging from $30 for 5 MPH over the limit to $135 plus $5 per MPH for speeds exceeding 20 MPH over the limit