Ticket agents, in the words of the song, have come a long way from St. Louis.

Once there was a person in the neighborhood who could order a ticket and save you a trip to midtown or the airport.Now there is a travel agent who may be styled an adviser or even a counselor.

What does the agent do in this evolved role?

According to a survey taken at the end of 1989 by the Louis Harris organization for the trade paper Travel Weekly, almost everything but actually take the trip.

The most remarkable statistic that came up in the Harris interviews with 706 travel agency offices showed that 48 percent of their clients did not just ask which airline, hotel or car-rental company to use, but asked where to go.

Much as travel agents welcome this broader role, since it holds out the possibility of a regular clientele that can be encouraged to use airlines, hotels, and other operators that pay the highest commission, it also has a down side. Agents are starting to be held responsible if they give clients bad advice or sell unsatisfactory services and are finding themselves involved in lawsuits or making cash payments to avoid suits.

Before the 50s, one travel lawyer said, good travel agents had detailed knowledge of what they were selling. They put together trips brick by brick, talking to each source on the way and tailoring tours for individual clients.

The upsurge of tour operators - another level between the traveler and the trip - has created a situation in which agents are picking tours by numbers and selling a product about which they may have little knowledge.

One agents' lawyer said there was no harm in this so long as the clients knew that the agent was merely an intermediary. But agents may be tempted to display expertise they may not have.

Judging by letters to this department, there is almost no imaginable way of being cheated, abused or both that American travelers do not suffer, from being abandoned in midtrip by tour companies to finding their reservations not honored to trying to deal with agents who refuse delivery of registered mail.

What the letter writers want is their lost vacations back, something no one can deliver.

Short of that, most want to roast the gizzards of everyone who had anything to do with the events. Lawsuits against tour operators and travel agents are a poor third because they require money for a lawyer, plus time.

But lawsuits are gaining. And courts are evolving a concept that a client can successfully sue if a travel agent behaved knowledgeably and could "reasonably" have known or should have known, for instance, that the hotel was being reconstructed, with work starting at 7 each morning.

Ten years ago, cases against travel agents usually fell solely under "agency law": the agent had a contract, even if not written, to sell the client certain things.

The client could sue if its terms were not fulfilled. But if the principals - the real suppliers, meaning the airlines, railroads, hotels and others - were known and identified to the clients, the suit would be against them. The agency could be sued only for its profits, meaning commissions, on a given trip. Commissions start at 10 percent for basic reservations.

Thomas A. Dickerson, a New York lawyer who specializes in consumer travel cases, said the courts of New York, New Jersey, Pennsylvania and Ohio were delineating the agent's new responsibility.

Jeff Miller of Ward, Klein & Miller in Washington said he saw such cases in California and Florida too.

Miller, whose clients are travel agencies and tour operators, said that the evolution of travel-agent law had been evolving rapidly in the last two years, particularly in cases in which tour operators strand clients.

Dickerson cites rulings that agents have a "fiduciary" responsibility, meaning that they are entrusted to do something that the clients cannot do themselves. Under law, courts hold fidiciaries to a high standard of care.

Rodney E. Gould of Rubin, Hay & Gould in Massachusetts is the lawyer for a New York travel agency that a client of Mr. Dickerson is currently suing.

Yet the two lawyers agree that a ruling in a 1989 New York case, in which the agent failed to tell the client who bought an air ticket that at the time in question visas were needed to enter France, demonstrates what should be expected of a travel agent.

In this case, Levin v. Kasmir World Travel, Justice David P. Saxe of the New York Supreme Court ruled for the plaintiff, saying:

"The travel agent is not merely a dispenser of tickets but also a fiduciary on whose expertise a traveler may reasonably rely." The plaintiff won the $600 cost of the ticket.

Dickerson, author of the reference work "Travel Law," (Law Journal Seminars-Press) cites other recent cases.

In a 1980 case, Prechtl v. Travel House of Garden City, N.Y., in which travelers were booked on a flight that had been canceled, the Nassau County (N.Y.) Civil Court ruled the agent guilty of negligence, saying: "The usual situation is that a person with little or no knowledge of the industry seeks an agent to help him. Like other agency situations, the agent here has a fiduciary responsibility."

Speaking for travel agents, Paul Ruden, senior vice president for legal affairs for the American Society of Travel Agents, said that agents were deeply concerned to find themselves having to live up to the standards that courts were imposing.

Agents, he said, are being put into the position of being virtual guarantors of all conditions on a tour and they cannot insure against all failures.

"These are all lower court decisions," Ruden said, "and we hope to be able to get a higher court to give a clear interpretation of what reasonable commercial obligations are."

Of the travel agent's role, Gould said: "Travel agents, when asked for advice, should give reasoned advice" or remain silent.

By reasoned, Gould means that the agent should state where the information came from, whether his recommendations are based on personal knowledge or just a listing.

In Gould's view, the advent of computer reservation systems opened the agent to greater risk.

"It takes away the direct contact with the carrier or hotel," he said. "If you had to call Air France, they would tell you a visa was needed, but the terminal does not."

Arthur Schiff of Schekter Rishty & Goldstein in New York was for nine years general counsel to the Society of Travel Agents, and he has drafted model disclaimers for agents.

"Things are evolving," he said. "Courts are becoming more aware of travel. Agents need to define carefully their roles."

He said dangers lurked for agents who were too eager to make a sale and did not disclose that other suppliers were involved.

"Where he discloses," Schiff said, "he shifts the risk from himself to the consumer."

The second paragraph of Schiff's model disclaimer "Notice to All Clients" says: "Because we act only as sales agents for these travel companies and maintain no control over their personnel or operations, only they can be responsible should any aspect of their travel arrangements not be to your satisfaction."

Of course, the agent may not want to put this before a client when the sale is about to close, and the client may not want to sign, and courts have disregarded disclaimers in any case.

The case Dickerson and Gould are litigating involves a $50,000 suit by Samuel H. Marcus of Queens, N.Y. against Zenith Travel of New York.

The suit grew out of a tour to the Orient put together by Hemphill Harris, a luxury tour operator that collapsed last fall, causing Mr. and Mrs. Marcus, on arrival in Tokyo, to be denied accommodations at the hotel where they had been booked. Dickerson has also filed a class action suit directly against Hemphill Harris and other parties.

The suit against Zenith is based on reports in the travel trade press last year that Mr. Dickerson maintains should have warned the agency that something was awry at Hemphill Harris.

Gould maintains that calls by Zenith to hotels that were substituted for the original hotels just before departure gave no indication that the new hotels would not honor the reservations.

On Oct. 12, Justice Saxe, who is presiding, ruled that the trial should go ahead on three of four of the Marcus complaints.

"The duties imposed on travel agents have increased as the role of travel agents in assisting customers make travel plans has expanded," Justice Saxe said.

"Beyond the duty to confirm, travel agents are expected to provide information which is necessary and of importance to the traveler."