The Orange County Transportation Authority (OCTA) will update the Costa Mesa City Council on Tuesday on the agency's efforts to widen the San Diego (405) Freeway and possibly the Corona del Mar (73) Freeway.

The projects could impact residential sections of Costa Mesa, and many residents are opposed.

For years, OCTA has been working with the state Department of Transportation on how to widen a stretch of the 405 in Orange County.

In 2006, OCTA approved the idea of examining a few scenarios that added one to two lanes in each direction between the San Gabriel (605) Freeway, which merges with the 405 in the Seal Beach-Los Alamitos area, and Euclid Street in Fountain Valley.

But then another alternative was born: widening the 405 from the 605 all the way to the 73 in Costa Mesa, with one of the lanes being an express car pool or toll lane. It would cost an estimated $1.7 billion, about $300 million more than the other choices that stay north of the Santa Ana River.

Costa Mesa officials and residents have come out strongly against any option that stretches into the city, records show.

In emails attached to the agenda for Tuesday's meeting, residents more than a year ago raised concerns that widening the 405 would close the Fairview Road bridge over the freeway and possibly increase traffic noise for adjacent neighborhoods.

Costa Mesa's then-Transportation Services Manager Raja Sethuraman criticized OCTA's assumptions going into its study on the project.

The organization overestimated traffic growth over the next 30 years and didn't mention the severe effect it would have on local traffic, with the Fairview bridge being a main artery to Costa Mesa's north end, Sethuraman said.

OCTA hasn't chosen which widening option it will go with, but it is wrapping up the environmental impact report for the three main choices, including the one that goes into Costa Mesa.

The report should be released to the public by the end of the month, OCTA officials said.

In other issues on Tuesday's agenda, the city will get its first glance at the preliminary budget for fiscal year 2012-13.

joseph.serna@latimes.com

Twitter: @JosephSerna