The Governor’s Office and the Arizona Department of Transportation announced Monday that the state has won a 90-million dollar federal highway grant to help expand and improve Interstate-17 north of Phoenix. The bulk of the grant will go to adding “flex” lanes between Black Canyon City and the Sunset Point Rest Area. The lanes will operate as a separate two-lane area to carry one direction of traffic at any one time depending on need, with movable gates to end control access. For example, the lanes could handle an extra load of traffic on northbound I-17 on Friday from Phoenix to Flagstaff, then return the favor on Sunday for southbound I-17. Construction will begin by 2021 and be completed by 2023.