AN ARBITRATION board's decision appears to eliminate what had been the strong possibility of a wildcat strike by transit workers here this summer. That should be a relief for riders as well as nearly 5,000 drivers, mechanics and other employes, but the most important issue involved remains to be addressed. Metro management merely lost a battle that it could have done without; there is still a war that it should continue to wage against the enormously expensive cost-of-living increases that it has had to pay under the contract covering these employes.

The contract has required quarterly increases equal to the full rise of the Consumer Price Index. The last time around, that meant payments of an 18 percent annual rate. Because the contract had expired and a new agreement is not expected from another arbitration panel before the fall, Metro had sought to withhold a July 1 increase and then pay whatever a new contract called for. But the expired pact stated that "all conditions in this contract shall remain undisturbed," conditions that the latest arbitration ruling cited in ordering the July payment.

Now that this unnecessary provocation by Metro management has been eliminated and all systems are likely to keep rolling without any illegal work stoppages, all parties -- the Metro board, union negotiators and taxpayers -- should focus on ways to curb Metro's outlandishly costly payroll. Some reasonable adjustment of the cost-of-living payments is essential, or else transit service and the jobs that go with it will have to be curtailed drastically. The budgets of local governments are tight, and time is short for some relief. The faster a new agreement is reached, the better.