Planners Modify Traffic Claims in Porter Ranch Study

Los Angeles planning and transportation officials said Wednesday that they are skeptical of a developer’s contention that a 1,300-acre project in Porter Ranch will make traffic in the northwest San Fernando Valley better than it would be without the project.

In a final environmental impact report released this month, city officials toned down a January draft study that said the $2-billion development would not cause unsolvable traffic problems.

“It tended to make it look like it was better than it really was,” T.K. Prime, a senior city transportation engineer, said of the draft report’s view of traffic. “We’re just trying to keep them honest.”

The proposal is for about 3,000 residences and 7.5-million square feet of commercial space to be built north of the Simi Valley Freeway in Chatsworth over 20 to 30 years.

“We’re always questioning what the real results will be,” said Frank Fielding, a senior city planner.

Report Changed

City officials changed the draft report, prepared for the Porter Ranch Development Co. by Engineering Technology of Sherman Oaks, where they did not agree with its conclusions.

In making a case that traffic will be better with the project than without, the draft said developer-financed traffic improvements will fully keep congestion at an acceptable level in and around the project.

But Prime deleted that assertion from the final report.

Regarding the Simi Valley Freeway, Prime added to the draft: “ . . . the project would use sizable portions of available capacity along some freeway segments and would result in adverse levels of service eastbound along the freeway between Tampa Avenue and Balboa Boulevard during the evening peak period.”

Prime said he based that comment on the draft report’s calculation that in the evening rush hour, eastbound freeway traffic would be at 91% of capacity between Tampa Avenue and Reseda Boulevard and at 97% of capacity between Reseda and Balboa boulevards.

The draft’s calculations were based on an assumption that the freeway will be expanded from three lanes to five in each direction through the area by the year 2010. Caltrans is expected to compare the calculations to those in an upcoming study of its own.

In another change to the draft, planners said Porter Ranch Development should not have to help pay for a bridge over Aliso Canyon.

The Sesnon Boulevard bridge eventually will be needed with or without the Porter Ranch project, Prime said.

In a separate correction to the draft, Fielding said the existing plan for the area allows only 650,000 square feet of commercial space, not 1.3 million.