Focus : End of the Cul-de-Sac : AFTER 14 YEARS, ‘KNOTS LANDING’ IS LEAVING THE BLOCK

Fourteen years ago, David Jacobs thought a series set in a suburban California cul-de-sac about fairly regular people in extraordinary circumstances would catch on. The genre of nighttime serials already included its parent “Dallas” and would soon expand to “Dynasty” and “Falcon Crest.”

Now, escalating production costs, soaring salaries and the desire to move on have claimed the last of the prime-time soaps. “Knots Landing,” TV’s third longest-running prime-time series will air a final two-hour episode Thursday.

“Let’s face it, the ‘80s are over,” Jacobs says. “As far as story lines and characters go, the show could have gone on another 10 years, but from a financial standpoint, it would have been very difficult.

“The fact that this show is expensive to produce is nothing new,” Jacobs adds. “We lost Constance McCashin, Julie Harris and Alec Baldwin, all exceptionally talented actors, for one simple reason, economics. And to get “Knots” on the air this year, the actors all took salary cuts and were each excluded from four episodes.

According to Leslie Mooves, president of Lorimar Television, “I don’t think we’ll ever see another series turn out 344 episodes. I think those days are gone. The economy is very different now than it was when “Knots Landing” premiered in 1979. And I do think the show has run its course. David Jacobs is a master storyteller and could have probably continued to come up with ideas for the show, but he’s also involved with other projects now and a lot of the actors were getting antsy to try new things.”

“I loved working on “Knots Landing,” Sheridan says, “and I particularly enjoyed the fact that Paige was so bright and ballsy and that there was never a dull moment in her life. I will miss the sense of family we all shared, but I do think it’s time for everyone to move on.”

“We talked about coming back for another year,” Jacobs admits, “but we decided, together with the network that this was it. I’m not sure that Bill Devane and Nicollette Sheridan would have come back and it just wouldn’t have been the same.”

“Knots Landing” had some very big years, and as the show got to be a hit, some actors emerged as stars and got big salary increases. “And it’s not that our cast was overpaid,” Jacobs explains. “They were and are tremendously popular and have very loyal fans--it’s just that there were so many of them.”

Michele Lee, who has been with the show since its inception, has had a hard time letting go of Karen, a character Jacobs describes as the lynch pin of “Knots Landing.”

“Mack and Karen were everyone’s next door neighbor,” co-star Kathleen Noone says. “Everybody could relate to them, they worked, they argued, they made up--they dealt with real issues.”

Dealing with timely social issues was one of the things “Knots” did so well, Lee says. “My favorite and least favorite story line was Karen’s drug dependence a few years back,” says the actress, who earned an Emmy nomination for her role in 1982.

“The beginning was difficult in that because of the addiction, she would just sit in a corner very withdrawn. On the other hand, it was also my favorite because as an actress, I really had something to sink my teeth into. And in addition to that, I thought the story was incredibly well researched and well presented and had an enormously positive impact.

“Knots Landing” has always had a very loyal core of viewers.” Peter Tortorici, vice president of CBS Entertainment says. “We would never willingly take a show off the air when people are still tuning in but in this case, we all felt it was time to say goodby. We hope that when people tune in to the final episode Thursday night, that they sell see the cul-de-sac and all the neighbors and feel a sense of nostalgia. And I don’t look at it as the demise of “Knots Landing.” I see the end as a culmination of an extraordinary accomplishment.”

A “Knots Landing Block Party” retrospective airs at 8 p.m. Thursday; final “Knots” follows at 9 on CBS .