If you are among the 4 1/2 million people expecting to see the Olympics here next summer, there are some things you should know to help you in your planning. Los Angeles has a reputation, far beyond its borders, for being a lot of communities in search of a city. The metropolitan area ranges over hundreds of square miles, filling the Los Angeles Basin, spilling over into the San Fernando Valley, and, seemingly, across its southern boundary line into Orange County. Those communities are connected by a network of freeways - more than 500 miles of them.
You've probably heard about L.A.'s freeways. And what you've heard has not been good, since they tend to make news when they aren't working well - when vehicles are moving slowly or not at all.
One of the worst such times is expected to come during the July 28-to-Aug. 12 Olympics period.
''It's next to impossible to calculate the number of vehicles on our freeways ,'' says Sgt. Gary Townsend of the California Highway Patrol Olympic Coordinators Office. ''But we can tell you that during the Olympics we expect there to be 2.7 million additional vehicle miles traveled.''
There's good reason for those mileage estimates.
The spread-out quality of Los Angeles is reflected in its Olympic venues. Because the Los Angeles Olympic Organizing Committee (LAOCC) decided not to build facilities just for the Games but instead to use, wherever possible, existing sites, you'll have to travel 25 miles to Long Beach to see yachting, volleyball, and fencing events; water polo will be 30 miles away at Pepperdine University. The farthest event, one part of the equestrian competition, will be at the Fairbanks Country Club in San Diego County, 110 miles to the south.
''We will have additional staff on hand . . . during that period. Message boards will tell of possible problems down the road, and we expect fast response from tow trucks and auto clubs,'' says Sergeant Townsend.
Not everyone expecting to see the Olympics will be coming from out of town. Since tickets went on sale June 14, tens of thousands of orders have been processed, - and southern Californians have bought 65 percent of those sold.
At present, 123 events are sold out: opening and closing ceremonies, gymnastics, swimming and diving, synchronized swimming, and tennis among them. Still, the committee will continue selling tickets to other events through May 4 .(Prices range from $3 to $95 and average about $17.)
Los Angeles is a city used to playing host. Five million visitors a month - some 40 million a year - come here. And the Olympic committee is expecting about 250,000 visitors each day for the XXIII Olympiad.
According to the Los Angeles Visitors and Convention Bureau, there are over 100,000 hotel rooms available in the Los Angeles Basin (including Orange County). A double room in a good hotel will cost you from $90 to $245 in 1984, with a middle range of $125 to $140. That is, if you can get one. Three-quarters of the area's hotels are already booked to 80 percent capacity for the Olympics period.
You would do well, of course, to try for accommodations near the Olympics area where you will be doing your spectating. If you can't find hotel or motel rooms available, you will find that more than 20 firms have been organized for the sole purpose arranging alternative sleeping spaces. Price estimates for these range from $25 to $50 per night for one, $50 to $70 for two.
For a list of those offering alternative housing, send a self-addressed, stamped envelope to the Greater Los Angeles Visitors and Convention Bureau, Attention: Olympic Housing, PO Box 71608, Los Angeles, Calif. 90071.
Remember that these firms are not endorsed by either the committee or the Visitors and Convention Bureau. Most do offer insurance against injury, damage, and theft, but you should check carefully the caliber of their accommodations and compare their prices against those at local hostelries before signing with them.
Many visitors will be using Los Angeles International Airport (LAX) as the gateway to the city. Those who do will find a spruced-up and, one hopes, smooth operation.
International visitors will especially benefit from the reconstruction. The new West Terminal, for arriving and departing foreign flights, will offer a that is two-thirds of the size of all existing LAX terminals. With 72 US Customs counters, it will be able to process close to 2,000 passengers an hour.
According to airport spokeman Jack Francois, LAX will have good directional signs in international symbols. In the International Terminal, multilingual greeters will assist non-English-speaking visitors. Information desks in each terminal, not just the International, will be staffed by representatives of the committee to assist Olympics visitors.
There is regularly scheduled motor coach transportation, by companies such as Airport Service Inc., between the airport and local hotels. Information kiosks are situated at arrival level, just outside terminal buildings. Expect to pay $ 15 or more round trip to outlying locations.
And, even in this land of the automobile, you might want to consider riding the city buses during the Olympics.
''Sixty-five percent of the people going to events at the Coliseum must take the buses,'' Sergeant Townsend says. That's because as many as 127,000 people a day are expected to compete for the 16,000 parking spaces on the grounds.
There will be some parking available in outside lots, of course, but some of parking spaces will be as far as two miles away, and fees could range as high as problems.
Bus travel can ease those problems.
Mark Littman, a spokesman for the Los Angeles Rapid Transit District, says, ''We're going to create a transportation system from scratch - 475 buses, totally separate from our regular service, that will concentrate on the Olympic sites.''
The transit district will offer three services for Olympics bus riders:
* Shuttle service to venues less than five miles apart - Dodger Stadium, the Rose Bowl, UCLA, and the Coliseum will be among sites visited on the back-and-forth routes, and those buses could go every minute or so, as demand warrants, at a cost of $2 a ride.
* Express buses departing from a central downtown location for specific Olympic sites at a cost of $4 one way.
* Park-and-ride buses, carrying people from suburban locations as far away as the San Fernando Valley to downtown, connecting up with express or shuttle service. They will cost $6 one way.
A special $10 ticket will be sold to allow all-day use of the city's buses, both regular and special Olympic. It will be available beginning July 14, two weeks before the Games begin. For information, call (213) 626-4455.