ONE SURE WAY to undermine a public policy of restraint is for officials to exempt themselves. We offer some examples today. One comes from Illinois, where the state legislature and the Cook County Board have just responded to President Carter's anti-inflation appeals by voting themselves fat pay raises -- 40 percent for the legislators and 30 percent for the board. Chicago's aldermen, unwilling to let this bandwagon pass them by, are weighing an even more excessive hike. When inflation czar Alfred Kahn correctly called such behavior "irresponsible," one alderman summed up the prevailing spirit by replying, "If Carter doesn't like it, he can go to hell."

The Illinois lawmakers are not the only ones helping themselves. Ohio's legislature has given itself a hefty raise. Locally, the District Council recently increased its own pay 17 percent and raised the mayor's salary 14 percent. Those increases are more justifiable, but in light of the administration's guidelines they too should be reassessed.

A different subject -- parking -- brings out the most blatant I'm-special attitudes among officials here-abouts. Recently the Council of Governments voted for the umpteenth time to try to make federal employees pay market rates for parking. District officials generally think that's a grand idea. But the preceding night the City Council had voted 9 to 1 to grant itself free District Building parking and write off some $15,000 in past parking rentals that the city has been trying to clooect.

So much for practicing what you preach. And the council is not the only offender on this score. Federal officials urge local leaders to get commuters out of their cars -- but won't raise parking fees at their own agencies. Congress imposes clean-air deadlines on the nation's metropolitan areas -- and maintains about 9,000 free parking places for its own.

Granted, ending parking freebies is not the most important step toward cleaning up this area's air. Because most of the gains will come from cleaner cars, the top priority for the District, Maryland and Virginia should be requiring annual inspections to make car-owners keep their pollution-control systems in good repair. The necessary laws may well get passed by next July, mainly because jurisdictions that fail to act could lose a lot of federal aid.

More effort will be needed, though. Even if pollution from other sources is also cut, and even if the full Metro system is built, COG estimates that the region will exceed the national hydrocarbon limit by 50 percent in 1982, the interim deadline, and by 39 percent in 1987, the final target date. Thereafter, as traffic volumes mount, the pollution, smog and health hazards will increase again.

The only lasting answer here is getting people to drive less. That is at least as hard as keeping wage and price increases down. The two problems are similar, in fact, because they both require changing a lot of habits and call for sustained self-descipline by official and citizen alike. Little will be achieved on either front if everyone waits for someone else to bear the cost and inconvenience first. And less will be achieved if officials keep indulging themselves. Until they show some leadership and forgo some of their own cherished perquisites, their clarion calls for austerity will have a pretty hollow ring.