Which freeway is considered the busiest in the United States?

The designation of the busiest freeway in the United States is often attributed to Interstate 405, particularly the segment that runs through the Los Angeles area. This stretch of I-405 is notorious for heavy congestion, accommodating an exceptionally high volume of vehicles on a daily basis, sometimes exceeding 300,000 vehicles. The factors contributing to its busyness include its location in a densely populated urban center, connecting key areas such as the San Fernando Valley, the Westside of Los Angeles, and the Los Angeles International Airport (LAX), making it a critical artery for commuters and commercial traffic alike.

Additionally, this freeway functions as a vital connector for multiple other major highways, adding to its importance and the volume of traffic it handles. The urban sprawl and ongoing economic activities in the surrounding regions further exacerbate the congestion experienced on I-405, cementing its status as the busiest freeway in the nation.