Release: NEW ANALYSIS: Regional Transportation Needs Could be met without Expanding I-5 Freeway

August 12, 2014


Nina Erlich-Williams
W: 510-336-9566
C: 415-577-1153

NEW ANALYSIS: Regional Transportation Needs Could be met without Expanding I-5 Freeway

Coastal Commission to vote on whether plan will proceed on August 13

San Diego – In advance of the August 13 California Coastal Commission meeting, an independent transportation expert is calling into question the analysis used by Caltrans to justify a massive expansion of the I-5 freeway in coastal San Diego County. The expansion would add four “managed lanes” to a 27-mile stretch of Interstate 5 north of San Diego up through Del Mar, Solana Beach, Encinitas, Carlsbad, and Oceanside. The commission is scheduled to hold a critical vote on the matter at its upcoming meeting.

Norm Marshall, president of transportation and land use consulting firm Smart Mobility, Inc., reviewed the 2010 Draft Environmental Impact Report (DEIR) for this project in 2010 and found that the analyses used an outdated version (circa 2003) of the San Diego Association of Governments (SANDAG) transportation model. The SANDAG Regional Transportation Plan adopted in 2007 indicated that I-5 traffic growth would only be about half that assumed by Caltrans in its project plans.

SANDAG’s 2011 analyses show that traffic will increase by 17 percent between 2010 and 2040, but the 2003 analyses used by Caltrans had predicted a much sharper increase in traffic: nearly 30 percent by 2030. The annual growth rate in I-5 traffic assumed by Caltrans is over 100 percent greater than the growth rate currently forecast by SANDAG. At this lower growth rate, the projections being used to justify I-5 expansion would not be reached until 2057, instead of 2030.

“SANDAG downgraded its predictions based on a number of factors: slowed growth due to the extended recession was one factor, as was lifestyle trends we’re seeing across the country,” explained Mr. Marshall. “Americans are making changes to shorten their commutes and/or cut down on single-car commuting.”

Much has changed for transportation planning in San Diego since Caltrans developed its modeling based on the 2003 data. AB 32 and SB 375 – state laws focused on reducing greenhouse gas emissions –have been passed, there was a major financial crisis that included the foreclosure of over 75,000 houses in San Diego County, and SANDAG is now planning for much more compact future land use than anticipated in 2003. Given that the data were badly outdated even in 2010, Caltrans was negligent in not updating its analysis when it finalized its freeway expansion plan in October 2013. Caltrans itself acknowledged that the traffic numbers are wrong for 2030 in the appendix of its final analysis, but has not updated its analysis in the main body of the EIR. If it did update its analysis accordingly, it would be clear that there is no pressing need to expand I-5 in the way the agency is proposing. Every “2030” number relied on by Coastal Commission staff for future traffic volumes, future congestion levels, and future air emissions in its justification for freeway expansion is wrong.

The Coastal Commission report indicates that one of the primary goals of the proposed project is to increase the transit mode share to 10-15% for peak-period commute trips. Since the newer I-5 traffic forecasts show growth of only 17 percent between 2010 and 2040, then a 10-15 percent transit share could meet most of that need. “Clearly, a transit first approach is needed,” said Mr. Marshall.

The SANDAG program EIR governing the I-5 project EIR has also been successfully challenged in the California Superior Court by the Cleveland National Forest Foundation. While the case awaits appeal, public agencies are technically allowed to continue to rely on the EIR’s findings.

Along with increased traffic, the freeway expansion would increase air pollution in the region, which already gets a failing grade from the American Lung Association. The massive expansion would also over time increase traffic and greenhouse gas emissions, in direct conflict with state laws calling for aggressive emissions reductions.

Greenhouse gas emissions are directly tied to climate change, and a major threat associated with climate change is sea level rise. Therefore, getting the analysis right should be of particular concern to the California Coastal Commission, which is charged with protecting California’s coastline. Because the proposed freeway expansion falls within the “coastal zone,” the commission must approve the project before it can move forward.

“The courts have already found the regional analysis that underpins the EIR to be faulty, and SANDAG itself has acknowledged traffic growth is unlikely to spike as severely as once predicted over the coming decades,” said Duncan McFetridge, president of the Cleveland National Forest Foundation, which commissioned Mr. Marshall’s report.

Community opposition to the freeway widening has been strong since the project was first proposed in 2004. The project has prompted concerns over loss of scenic vistas (Caltrans plans to erect sound walls along the expanded corridor that would block ocean views). Opponents also cite concerns over economic impacts due to increased traffic and lost regional tourism-related revenue, as well as dismay at continued investment in car-oriented transportation at the expense of public transit.

“The commissioners should follow not only the letter of the law, but also the spirit,” added Mr. McFetridge. “They should require Caltrans to prepare a more robust EIR that fully explores the benefits of transit before rubber stamping the freeway expansion plan.”

The California Coastal Commission will consider the I-5 expansion plan at its August 13 meeting which will commence at 9:00 a.m. at the Catamaran Resort, 3999 Mission Blvd., San Diego.

The Cleveland National Forest Foundation is a nonprofit group dedicated to preserving the plants, animals and other natural resources of Southern California mountains by protecting the land and water they need to survive. For more information, see: and


NOTE: CNFF has submitted the following public comment letters to the Coastal Commission regarding the North Coast Corridor Public Works Plan:

January 6, 2014
July 21, 2014 comments (including expert analysis from Norm Marshall, of Smart Mobility, Inc.)
August 11 supplemental comments


Caltrans Overestimates I-5 Growth

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