Those apps are helpful for daily use, like commuting and getting across town. ADOT Alerts is for major, unplanned traffic impacts, like a crash that closes I-10 near Casa Grande or a snowstorm that shuts down I-40 near Williams, that require travelers to take an alternate route or delay travel. When such an event occurs, we’ll send alerts to mobile devices in the affected areas, providing information to travelers and giving them the choice to re-route or delay their travel plans.