Frequently Asked Questions

The I-405 freeway experiences heavy traffic congestion and conditions are expected to worsen. Built in the 1960s, the freeway carries between 257,000 and 370,000 vehicles per day depending on location. Near the L.A. County line, the I-405 is the most heavily traveled freeway in the nation and both the regular lanes and carpool lanes are congested daily during rush hour and on weekends.

Traffic along the corridor is expected to grow approximately 35 percent by 2040. Improvements are needed to enhance traffic flow, accommodate growing traffic demand, relieve congestion, and improve overall mobility. The I-405 Improvement Project is critical in order to accommodate expected employment, population and housing growth in not only Orange County but throughout Southern California.

For construction updates, visit the I-405 Improvement Project.