When Florida became the first state in the country totally to deregulate intrastate trucking and buses, industry executives predicted anarchy. They feared an excess of free enterprise would paralyze the state's transportation system. At least, that's what lobbyists told the legislature.

But regulation lapsed at the end of June under a "sunset" provision of the law, and predictions involving the death of trucking proved to be greatly exaggerated.

A recent survey of the transportation industry in Florida showed that the immediate effects were:

Price adjustments, both up and down in both trucking and busing.

Some routes added, others dropped.

A surge of small new trucking companies filling gaps left by bigger ones.

A surge of new ridership on some bus lines where fares were cut and routes added.

A vice president of Greyhound Bus Lines told a recent Interstate Commerce Commission seminar in Washington that his company had opposed deregulation in Florida but was now pleased because it found that Greyhound could better allocate resources without having to deal with state government regulations. But he cautioned moving "too fast" on deregulation nationwide.

The ICC has commissioned a $200,000 study of the impact of deregulation on Florida, particularly with respect to five major areas:

Penetration of the Florida market by truckers from other states.

Price options and discounts offered shippers and consumers.

Effect on small communities of changes in service by truck and bus lines.

Quality of service.

The number of company failures caused by deregulation.

The Florida survey, conducted by a Miami consulting firm (Industrial Traffic Consultants, Inc.), found that bus lines responded to deregulation by cutting fares and dropping service to some towns and some routes. Florida Trailways cut fares 10 percent between intrastate points and offered discounts for children and elderly riders. A company spokesman said the reduced rates produced as much as 20 percent more ridership on some runs.

Trailways dropped some of its less lucrative runs, especially in small towns, but state representative George Sheldon (D-Tampa) said most of the points dropped by Trailways have been picked up by other carriers. Sheldon led the successful deregulation fight in the 1980 Florida legislature.

By dropping some routes and some stops, Trailways cut its trip time on the 250-mile Tallahassee-to-Tampa run by more than two hours, and shortened other trip times by similar amounts. It also added 1,620 miles a day of routes connecting 16 towns that previously had not had bus service.

Gulf Coast Motor Lines, running routes in the Tampa Bay and Orlando areas, dropped 14 of its regular routes within two weeks of deregulation. An official said the company could make more money on its charter services. The cutbacks affected about 5,000 riders, but the company says it did not get a single complaint.

Greyhound dropped service to 34 towns, mostly in rural north and central Florida, producing some complaints, but Sheldon said most residents didn't realize they had bus service and didn't notice losing it.

On the other hand, according to Sheldon, charter bus rates in Florida have dropped by between 30 percent and 50 percent and the industry has almost doubled in size.

Truckers also dropped many small communities from their regular routes, but almost overnight small independent truckers stepped in to pick up the slack. Bus lines, no longer restricted in the kinds of package express they can handle, have taken over some of the small-town shipping. In some cases, the added package revenue kept bus lines from dropping passenger service.

A major problem for Florida truckers is that out-of-state truckers bringing cargoes into Florida now can haul new loads out instead of deadheading back. Previously, regulations against "backhauling" required the trucks to return empty. A Tampa trucker, Bill Smalley, said "these companies are selectively choosing their backhaul freight and are charging lower rates to secure shipments than we possibly could. If they can fill an empty trailer even part of the way, it's all gravy."

William Bostic, an executive with Commercial Carrier Corp. in Auburndale, said his firm has lost some business to interstate truckers, but he said customers are coming back after experimenting with the cheaper trucks.

"Our best customers are finding they cannot operate on a catch-as-catch-can schedule and are coming back to us," said Bostic. "We offer them high quality and regular service and they realize that jumping around will cost them more in the long run."

It was mostly the larger companies that lost business with deregulation. Independent truckers have found the market much looser. The Miami survey found that the total number of trucking firms in the state jumped about 25 percent after deregulation. Most of the firms are going after the "gravy accounts" in large urban areas, according to the survey.

The antitrust division of the Florida attorney general's office is preparing to keep closer watch for predatory anticompetitive practices by larger carriers.