Orange County Transportation Authority

I-5 Central County Improvements

Central I5


Motorists frequently experience traffic congestion on the I-5 freeway between SR-55 and SR-57 and research indicates that delays likely will increase.  According to recent studies, 390,000 motorists travel this route every day. By 2030, that daily number is expected to rise to 464,000 – an increase of 19 percent.

Fortunately, relief is on the way. Caltrans, in partnership with OCTA, is proposing to add a second carpool lane in each direction to relieve traffic congestion, alleviate bottlenecks and improve traffic operations on this corridor within the cities of Santa Ana, Orange and Tustin. The project also includes removing the I-5/Main Street HOV on- and off-ramps.


Construction Costs: $42.5 million

Current Project Phase

The project is at the end of the environmental review phase. Caltrans is the lead agency and is responsible for approving a proposed preferred alternative; OCTA is the sponsoring agency. The environmental review process is mandated by the California Environmental Quality Act (CEQA) and the National Environmental Policy Act (NEPA). In general, the purpose of the environmental review process is to identify the project’s potential environmental impacts, and to develop measures to avoid, minimize and/or mitigate these impacts.

Caltrans and OCTA are proposing to add one HOV lane in each direction on a 2.9-mile stretch of Interstate 5 from State Route 55 to State Route 57 and to remove the southbound off-ramp and northbound on-ramp HOV structure at Main Street, referred to as the "Main Street HOV drop structure."

This is to inform you of the notice of availability of the Negative Declaration/Finding of No Significant Impact for this project. A copy of the final environmental documents can be viewed at

CEQA and NEPA Resources

For more information on CEQA and NEPA, please visit the following websites:


What's Next

Next up is the Final Design phase, which involves surveying and collecting data on items such as:

  • Existing road and bridge conditions;
  • Traffic volumes;
  • The ratio of cars to trucks and buses;
  • Crash statistics;
  • Terrain and soil properties;
  • Drainage capabilities;
  • Utilities that will be affected; and
  • Possible future development in the area.

Experts including transportation planners, engineers, environmentalists, landscape architects, geologists and others will use the data to identify trends to determine how best to build the project for improved travel conditions and minimal environmental effects.

Anticipated Project Schedule

Community Outreach

As the project moves into the final design and construction phases, we will continue to keep residents, businesses and community leaders informed. We are actively meeting with key groups, homeowners associations and businesses in the area. Please contact us to schedule a presentation or for additional project information.


Project Contact

Nicolette La Piana
Associate Community Relations Specialist
(714) 560-5787

Chris Boucly

Project Contact

Chris Boucly
Community Relations Officer
(714) 560-5326