PRINCE GEORGE'S voters can congratulate themselves for coming to grips wisely with the single most important obstacle in the way of the county's progress: TRIM, that rusty lid on property tax collections that has been stifling confidence in the ability of Prince George's to prosper. At last, and by an overwhelming majority, residents said "Yes" to a modest but critical adjustment of TRIM that is estimated to yield $6 to $8 million in additional revenues next year for public education and safety. But the impact extends well beyond these immediate budget opportunities.

When County Executive Parris N. Glendening points out that this was a vote of confidence in the future of Prince George's, he is not overstating the significance. TRIM clearly has had an increasingly negative effect on the county's ability to get money from the General Assembly, and understandably so if it wouldn't help itself in the process. And TRIM was threatening to diminish markedly the county's financial standing in general and credit rating in particular.

That had to worry business leaders and others seeking to attract new ventures and the jobs and revenues that come with them. And it worried enough residents not merely because of its increasingly harsh consequences for education and public safety but because it was denying the potential of Prince George's to become an even more attractive place to live than it has been. The beauty and diversity of the county were increasingly at stake.

The modification of TRIM will work no immediate wonders. But it should renew a sense in the county, the region, the state -- and Wall Street, too -- that good management and confidence are in place in Prince George's.