LAS VEGAS, NEVADA - SEPTEMBER 19: An exterior view shows Allegiant Stadium, the USD 2 billion, 65,000-seat home of the Las Vegas Raiders, west of a marquee at Mandalay Bay Resort and Casino on September 19, 2020 in Las Vegas, Nevada. The Raiders will play their first game as Las Vegas' NFL franchise at the glass-domed facility against the New Orleans Saints on September 21, coinciding with the 50th anniversary of the league's first "Monday Night Football" broadcast. (Photo by Ethan Miller/Getty Images)

LAS VEGAS (AP) — Work has begun to remake one of the busiest interchanges on the busiest freeway in Nevada in a project that officials say will ease access to Allegiant Stadium, T-Mobile Arena and the resort-lined Las Vegas Strip. But officials acknowledge the planned three years of work will create big construction headaches. Gov. Steve Sisolak and U.S. Transportation Secretary Pete Buttigieg marked the start this week of the $305 million upgrade to Interstate 15 and Tropicana Avenue. Officials say the overpass will be demolished and rebuilt — and the freeway will be shut down several times before work ends in 2025. The interchange is a key choke point on the main traffic route from Salt Lake City to Los Angeles.