IN A SORRY SHOW of provincial thinking (a vote at once unanimous and narrow), the leaders of Fairfax City have decided that their territory should start seceding from the region: They've decided to take the city entirely out of the Metrobus system. This is the same council that two years ago pulled the plug on a proposed Northern Virginiagas sales tax that would have been used to help finance public transport. Now, according to some convoluted math by city manager George E. Hubler,the members figure they might save between $35,000 and $73,000 by dropping out of Metro and arranging rush-hour-only chartered bus service to and from Washington. So, effective Jan. 2, a private company will run seven morning express buses to downtown Washington, with a stop at the Pentagon, and seven the other way each e been serviced by Metro with 40 rush-hour round trips andof the carless, the elderly or domestic workers - who have been serviced by Metro with 40rush-hour round trips and23 mid-day round trops between 6 a.m. and 10 p.m. City manager Hubler points, feebly, to a citizen survey made in July, which he says shows that "a majority of city residents find Metrobus service inadequate, inconvenient or tooexpensive.

But that's all in how you look at the numbers. Some 33 per cent of the people did find Metro service inconvenient or inadequate. How will limited, one-way, rush-hour service address that complaint? Moreover, almost as many people - 32 per cent - had a "generally favorable opinion" of Metro. Another 25 per cent said Metro fares were too high; but under the council plan they'll saveonly 20 cents on the current one-way Metro fare of $1.30.

Now, Fairfax City may well continue to do its own selfish isolationist thing on many fronts. Indeed, we're tempted to say that it should also be left to dispose of its own schools, clean up its own air and maybe even put up toll gates at the borders. Fortunately, the more responsible leaders of local governments hereabouts recognize the importance of regional cooperation in providing essentialpublic services - and, we trust,will continue to find more intelligent ways to resolve the complex financial questions that these joint ventures entail.