Traffic Catches Up to Growth : Chatsworth: Afternoon rush hour will be terrible despite promises by developers, who are adding 1 million square feet of offices to an industrial park, studies say.

Commuters and residents within the next two years can expect the worst sort of bumper-to-bumper traffic workday afternoons on streets surrounding a Chatsworth industrial park where about 1 million square feet of offices are being added, city studies show.

Despite street improvements pledged by developers, drivers at major intersections west and northwest of Northridge Fashion Center will have to wait while traffic signals turn to green, then to red, then to green again before getting through during afternoon rush hours, according to studies of the area prepared for the Los Angeles Department of Transportation.

And that prediction does not even consider traffic that would be created by the Los Angeles County Courthouse proposed for the corner of Plummer Street and Winnetka Avenue, planners say.

Traffic will slow to a crawl at every signal-controlled intersection on Winnetka and Corbin avenues as far south as Parthenia Street and as far north as Devonshire Street, even with the addition of traffic lanes and turning lanes pledged by developers, according to the traffic study commissioned by city planners. Winnetka and Corbin avenues are the main corridors to get to the Simi Valley Freeway.

Morning traffic will be better, with gridlock conditions expected only at Corbin Avenue and Parthenia Street, according to the study.

The bad news about traffic in the area comes in a traffic study required by the city to be completed by consultants Donald Frischer & Associates for Great Western Savings, whose 780,000-square-foot office complex will occupy the next-to-last large parcel in the park. But because the offices built in the rest of the park during the past eight years all fell within allowable uses in the area, and faced little neighborhood opposition, the accumulating traffic problem was not reviewed by city decision makers.

The industrial park is within a much larger West Valley area long zoned for such commercial uses and now that it is fully developed, relatively little can be done to change the situation, planners say.

But instead of protests from nearby residents, developers building in the area are enjoying homeowners’ praise.

“With the exception of the courthouse, we’ve approved every building that’s gone in there,” said Harry Godley, co-chairman of the Chatsworth Homeowners Committee. “We’ve worked with the contractors and now we have a beautiful park that is a credit to everybody.”

Godley said he and other members of the homeowners group--whose members live mostly in the neighborhoods north of the site above Plummer Street--led a successful fight eight years ago against plans by Southern Pacific railroad to provide 24-hour rail deliveries to companies operating in the 158-acre industrial park.

At the time, the railroad firm had hoped to build 20 rail spurs from its nearby line to carry goods to and from the warehouses and manufacturers envisioned for the site. But the homeowners group prevailed and the railroad agreed to drop the plan.

Since then, developers building in the area--now called the Southern Pacific Northridge Industrial Park, even though it is located in Chatsworth--have successfully courted the support of the homeowners group. The industrial park is bounded by Plummer Street, Winnetka Avenue, Corbin Avenue and Nordhoff Street and the Los Angeles Times’ Chatsworth plant is located there.

“We had meeting after meeting with neighbors,” said traffic consultant Donald Frischer, whose firm was hired by Great Western Financial Corp. for a 780,000-square-foot project now under construction at the industrial park. “By the end, to the best of my knowledge, everyone was smiling.”

The only complaints by Godley and other members of the Chatsworth homeowners group have been lodged against the courthouse proposal, which has been given preliminary approval by the Los Angeles County Board of Supervisors. “It would bring to our streets the type of people who are there for felonies, robberies and other crimes,” he said.

Godley said he and neighbors are somewhat concerned about the increase in traffic created by the industrial park but believe that matters would have been worse if the city had allowed rail lines built there.

“Of course when I moved in, there were nothing but orange groves there,” said Godley, who has lived in his house 31 years.

New projects at the industrial park that, with the exception of the proposed 9.3-acre courthouse site, will be complete are:

* A 780,000-square-foot complex by Great Western Financial Corp. at the southeast corner of Oakdale Avenue and Prairie Street. Work has started on about half of the project, including a 10-story office building.

* A three-story, 86,000-square-foot Litton Federal Credit Union building at the northeast corner of Oakdale Avenue and Prairie Street, which is expected to be completed this fall.

* A 100,000-square-foot office building, to be known as the Shepher Corporate Center, which is expected to be completed by the end of 1991 at the northeast corner of Winnetka Avenue and Prairie Street.

Times staff writer Betsy Bates contributed to this story.

Chatsworth Building Projects The Projects 1. Los Angeles County Courthouse (proposed) 2. Shepher Building: 5 stories; 100,000 sq. ft. 3. Litton Federal Credit Union: 3 stories; 86,000 sq. ft. 4. Great Western Building: 10 stories; 780,000 sq. ft. Traffic Effects: Traffic engineers rate congestion on a scale of A thourgh F and predict afternoon bumper-to-bumper tie-ups at the intersection labeled E and F above.