EDITORIAL : STUCK IN THE SLOW LANE; THAT COULD BE THE REGION'S FATE IF PLANS AREN'T MADE FOR GROWTH.

IT'S encouraging to see elected and appointed officials - we refer to leaders of the Southern California Association of Governments - pay attention to difficult long-range problems. Most political figures rarely look beyond the date of the next election or appointment.

Take, for example, that draft report issued by SCAG on Thursday. It tackles a formidable subject by offering a picture of what life in the Los Angeles region might be like in 2020 if adequate steps aren't taken to accommodate growth.

And a disturbing picture it is. The study assumes that the region's population, which was 15.6 million in 1994, would grow to 22.4 million in 2020. That translates - assuming that only currently planned projects and other improvements are completed - into 966 miles of extremely congested freeways (compared with 34 miles today) and an average afternoon peak highway speed of 24 mph, instead of 32.4 mph.

(We imagine traffic would be far worse for some commuters, such as those forced to use the 101-405 freeway interchange, if public officials fail to deal with problems that are painfully evident now.)

Whether all this growth will occur is a matter of speculation. It might not if a lot of people take seriously a remark commonly attributed to Yogi Berra: ``Nobody goes there anymore - it's too crowded.''

There also is a question of whether there will be enough water to sustain that growth. Periodic droughts are a fact of life in California. Meanwhile, little is being done to replace the water that Southern California will lose in the not-too-distant future when Arizona demands its full share of the Colorado River allotment.

Nevertheless, it would be foolish not to anticipate a lot more growth during the next quarter century and make plans for it. That's what SCAG tried to by making a variety of recommendations, from improving highways and public transportation to doing a better job of balancing jobs with housing.

We aren't suggesting that SCAG has all the answers. It might be dead wrong in some instances.

Nevertheless, SCAG has performed a useful service by alerting the public and affected public agencies to potential problems, and presenting some options for dealing with them. We urge the leaders of those agencies to seek public input and start thinking about what they need to do before it's too late.