Measure M Upheld by High Court : Transportation: O.C. is free to proceed with freeway, other projects financed by sales tax that voters OKd in 1990.

The state Supreme Court on Thursday rejected a challenge to Orange County’s half-cent sales tax for transportation improvements, removing the final roadblock to a wide-ranging, $3.1-billion program.

Justices voted 6 to 1 without comment to let stand lower court rulings that upheld the sales tax, known as Measure M, in the face of challenges by Drivers for Highway Safety, Citizens Against Unfair Taxation and the Libertarian Party Central Committee.

“This means it’s all over,” said San Juan Capistrano rancher Tom Rogers, who heads Citizens Against Unfair Taxation. “We gave it the good fight.”

The Orange County Transportation Authority had already decided to spend as much as $180 million from Measure M on street and highway projects in the next few months without waiting for Thursday’s ruling. But the court’s action allows the OCTA board to proceed in September with a planned borrowing of $260 million against future Measure M tax receipts. The money is expected to come from the sale of bonds.

Construction schedules, based on the assumption of success in the courtroom, have already been established for most Measure M projects. But individual OCTA board members may still lobby among themselves to advance some of their pet projects.

If the OCTA board approves a staff-proposed 1992-93 budget of $712.9 million unveiled Thursday, most of the money from Measure M will be spent on:

* The massive, $1.6-billion Santa Ana Freeway widening effort.

* Reconstruction of the confluence of the Santa Ana and San Diego freeways, known as the El Toro Y.

* The addition of car-pool lanes south of the El Toro Y.

* Purchase of rail rights of way and rail cars.

* Neighborhood street improvements.

* The streamlining of some thoroughfares into so-called “super-streets.”

The OCTA board will vote on the budget June 22, after a public hearing on June 8. The board held a workshop on the budget Thursday but took no action and was unaware of the Supreme Court decision until after the session ended.

“There’s no more ifs, buts or maybes about it,” said OCTA attorney Kennard Smart after learning of the court ruling. “We’re on our way.”

Tax opponent Wayne King of Drivers for Highway Safety said of the decision, “That’s too bad.”

King said he would wait to talk to attorney Mark S. Rosen before commenting further. Rosen and Roger Bloxam, a plaintiff from the Libertarian Party, both were unavailable for comment.

In their lawsuit, the plaintiffs claimed that Measure M, which was approved 54% to 46% by county voters in November, 1990, was unconstitutional because it should have needed a two-thirds majority to pass under Proposition 13, the 1978 tax reform initiative.

But the Supreme Court’s ruling Thursday echoed its decision only two weeks ago not to hear a similar appeal against a similar tax approved by Los Angeles County voters.

In both cases, defense attorneys argued successfully that the taxes involved are specifically exempt from the two-thirds majority requirement because the transportation agencies themselves and their taxing authority were approved by the state Legislature before Proposition 13 and thus were not created in order to bypass tax limits.

“We had to take it all the way to the Supreme Court or we would never have known that Measure M was legal,” said Bill Ward of Drivers for Highway Safety, a small, grass-roots organization that favors expenditures on new freeways instead of car-pool lanes and rail transit. “If you don’t swing, you never hit.”

Rogers, meanwhile, said he was disappointed by Thursday’s court decision partly because it leaves the plaintiffs without any of the concessions that may have been won in settlement negotiations held during the course of the legal challenge.

For example, Rogers said there had been some discussion of a settlement in which the anti-Measure M forces would receive some money to cover their court costs, or changes in the hours of operation of the county’s car-pool lanes. Drivers for Highway Safety had sought to have the lanes converted to general-purpose lanes except during peak morning and evening traffic periods.

But OCTA officials said there never was any serious movement in the negotiations because the Libertarian Party wanted to go all the way to the state Supreme Court.

Rogers predicted that OCTA will seek another tax increase from voters in a year or two to help finance a planned monorail or other elevated transit system that now is only partially funded.

“Their appetite for taxpayer dollars is never-ending,” Rogers said.

OCTA officials concede that such a tax measure may be needed but add that there has been no serious consideration so far.