As city officials unveiled a scale model of the Salt Lake International Airport this week - showing what $115 million worth of improvements would look like in the next 18 years - their optimism and long-range planning must be applauded.

Most cities and most airports - and Salt Lake City is no exception - struggle with day-to-day problems that take up most of the available time and dollars.But city officials also are looking far into the future, showing a willingness to invest now to make something special out of the airport and the salt marshes of the city's largely undeveloped northwest quadrant.

This ambitious plan includes making the already-excellent airport into a "world-class" facility and building golf courses, industrial parks, and other facilities in the surrounding area.

Airport plans, to be completed by the year 2006, call for construction of an additional 12,000-foot runway for $60 million to $75 million; doubling the size of Terminal 2, a $10 million project that will expand baggage and ticket areas and provide a new Delta Airlines tower; construction of a $30 million, four-levelparking complex.

None of the improvements will cost taxpayer dollars. The airport is operated by the Airport Authority, a quasi-independent body, and pays all its own expenses. The bonds issued to cover the new construction in the next 18 years will be paid out of the airport's own revenues.

Parking fees will be raised Nov. 1 to help offset the cost of the first $30 million bond approved earlier by the City Council to finance the multi-level parking complex. Half-hour parking rates will go from 35 cents up to 50 cents, and all-day parking will go from $2.85 to $3 per day.

In addition, the airport qualifies for several million dollars in federal money from the Airport Trust Fund to help finance improvements and repairs.

City and airport officials clearly are thinking big-and that's the way it should be. It would be folly to refuse to act until overcrowding forces a decision.That would cost more in the long run. An optimistic outlook requires that the airport get ready now to handle the growth that lies ahead.