SALT LAKE CITY -- The Senate approved a measure Friday to increase the speed limit from 75 to 80 mph on two key stretches of Top of Utah freeways.The increase is on flat, straight portions of Interstates 15, 80 and 84. One stretch is from Brigham City to the Idaho border, and another from Tremonton to the Idaho border. The measure, HB 83, now moves to the desk of Gov. Gary Herbert.Sen. Scott Jenkins, R-Plain City, the Senate sponsor, minimized one lawmaker's concerns that increased speeds would lead to poor air quality along the Wasatch Front.