SAN DIEGO -- The debate continues over a proposed expansion of Interstate 5 between La Jolla and Oceanside, as Caltrans wants to add as many as six new lanes in that stretch.

On Friday, the 10News media partner Equinox Center hosted a discussion on the subject involving Caltrans District Director Laurie Berman and state Sen. Christine Kehoe, who has written a bill about the expansion.

"The growth that's coming to the region is going to come whether we do anything to I-5 or not," Berman said.

Kehoe, who is proposing more public transportation along the corridor, said, "It's not if it should be widened, it's how it should be widened."

Kehoe's bill originally said the highway widening couldn't begin until public transit projects in the area were completed, but that bill was met with opposition.

"It simply wasn't practical, as far as transportation choices go and as far as getting support in Sacramento," said Kehoe.

Kehoe modified her bill, which now says freeway construction can go on at the same time as mass transit improvements, like more Coaster trains.

Berman said drivers are going to face increasingly long drive times. She said right now, driving on I-5 from La Jolla Village Drive to Oceanside takes, on average, 38 minutes.

"If we don't do anything to the I-5 by 2030, that average trip time is going to be 70 minutes," Berman said.

Kehoe wants what she calls a "slimmed down" version of the expansion, which would perhaps include four new lanes instead of six.

"A little less freeway, more environmental enhancements," said Kehoe.

Residents have expressed concerns about increased noise and more air pollution with the added lanes. Dennis Ridz, chair of the Torrey Pines Community Planning Board, attended Friday's meeting and said he was concerned about more traffic on roads leading to the freeway.

"We're just moving the traffic jams up the side roads," he said. "What are we going to do about that?"

Others said there is a lack of new ideas and new thinking.

"We're not planning with creativity, an open mind, or any experimentation," said Del Mar resident Sherri Neasham.

Businessman David Brown agreed, and added, "We're supposed to be cutting edge, and we're talking about mid-1950s kinds of solutions."

The widening of I-5, which could begin as early as 2013, could cost up to $4.5 billion.

Caltrans said the stretch of freeway currently gets 700,000 traffic trips a day. By 2030, they say that could rise to one million a day.

The Equinox Center, which set up Friday's meeting, is a nonprofit group that brings people together to develop solutions to the area's growth challenges.