American drivers, it seems, are anything but confident that the family auto is a reliable machine that will always get them where they want to go. Millions of them are paying annual fees (about $30 to $50) to join motoring clubs where the primary benefits are emergency road assistance or a tow if the car breaks down or doesn't start.

The oldest and largest of the clubs is the American Automobile Association, established in 1902. The AAA is an affiliation of 165 regional organizations throughout the United States and Canada -- including AAA-Potomac, the Washington-area club -- that has grown to an overall membership of more than 26 million. Another of AAA's major benefits is helping members plan vacation driving trips.

At least a dozen other national auto clubs also have emerged, mostly in the past two decades, and offer similar benefits to the driving public. Among them are clubs operated by oil companies, such as Amoco, Mobil, Exxon, Chevron and Shell; two large merchandise chains, Montgomery Ward and Sears Roebuck; at least one auto manufacturer, Ford; two travel card firms, American Express and Diners Club; and a senior citizens organization, the American Association of Retired Persons.

Even a magazine, Reader's Digest, is currently testing a new auto club, Drive America, among a small sample of its 16 million monthly subscribers.

Sooner or later, most drivers are going to receive a membership solicitation in the mail from one or more of these clubs, which should prompt at least two basic questions: "Is an auto club membership something I really need?" and, if the answer is yes, "Which of the many clubs is best for me?"

The answers to both questions must be based on individual circumstances, but there are guidelines to help you reach a decision.

Auto clubs advertise a variety of benefits that divide roughly into two categories: emergency help and trip-planning assistance. Usually it is the emergency benefit -- somebody to call when your car won't run -- that is most important to auto club members.

All of the clubs provide emergency road help in one of two distinct ways: They either send a truck from their own network of towing services, or they ask you to arrange for your own towing by calling any available service. (Afterward they will reimburse you for the cost up to a specified amount, which generally ranges from $40 to $75, depending on the club.)

Both the AAA and the Amoco Motor Club, a 4 million-member club celebrating its 25th anniversary this year, have their own network of trucks with whom they have contracted for service. The AAA says it is linked to 18,000 auto-service facilities; Amoco says it has 5,600 facilities in its network. Amoco's trucks also provide the emergency help for such other clubs as the American Express Driver Security Plan, the Diners Club Motor Plan, the American Association of Retired Persons Motoring Plan and the Reader's Digest club.

Amoco has recently installed a new computerized dispatch system, which, according to national manager Rudy Murcinko, "is unique." From anywhere in the country, he said, you can call its toll-free number, and while you are on the phone, Amoco will arrange to have a truck sent out. AAA offers the same service when you have car trouble within your membership region. If you call the AAA's toll-free number from outside your region, as a spokesman explained, AAA will give you the number of two nearby services, but you must make the additional call to get one of them.

With either AAA or Amoco (and the clubs that use its service), you only have to present your membership card to get emergency assistance; there is no additional cost.

The other auto clubs described in this article operate under the reimbursement plan: You call the service facility of your choice, and then the auto club reimburses you later up to a specified amount. One exception is the Allstate Motor Club, a 1.4 million-member organization operated by Sears Roebuck. It uses both the reimbursement system (in most states) and the network system (in six states: New York, New Jersey, Illinois, Michigan, California and Florida).

Is one way better than the other?

When you call AAA or Amoco, they assist in getting service to you, and they contend that if a towing firm has people waiting, members get priority over nonmembers. Once a truck arrives, you need only show your card; in most circumstances, there should be no additional charge for the help. (There may be a charge if you want to be towed to a place other than the service station from which the truck was dispatched.)

The reimbursement clubs argue, however, that their arrangement gives you flexibility to find the service firm that can get to you quickest, rather than restricting you only to the firms that are part of a network, which may have a backlog of calls. "You can call the closest, fastest service possible," said Rich Hansen, spokesman for the Shell Motorist Club. You do have to make your own search, however, and you must pay up front. You are reimbursed after submitting the service firm's receipt.

In either case, a call for emergency help generally means a truck will be dispatched to your car to provide such basic assistance as starting a dead battery, changing a flat tire if you have a good spare, delivering gas, replacing a fan belt, unlocking a car door, pulling you out of a ditch after a snowstorm, or giving you a tow back to the service station.

None of the auto clubs makes anything but minor repairs on your car while it is in your driveway or on the side of the highway. The car is towed back to the service facility for repairs, in part to get you off a busy highway or road for safety's sake.

AAA-Potomac, which has about 471,000 members in the Washington area, averages about 1,050 service calls a day, according to spokesman Douglas J. Neilson, who estimated that 80 percent of the membership has sought emergency help. During the evening rush-hour snowstorm of Feb. 24, the club got 200 calls in one hour.

Supplementary emergency benefits -- most or all of them offered by all auto clubs -- may include up to $500 in hotel, meal and transportation expenses if your trip is interrupted by a damaging car accident more than 50 to 100 miles from home; partial reimbursement for legal fees if you are charged with a traffic violation; bail-bond posting; emergency check-cashing privileges; lost credit card protection; and a lost-key registry. The clubs vary in how much they pay for these expenses, though not by much.

The second category of benefits is travel-planning assistance. The primary benefit is trip planning. You mail in or, in some clubs, phone in your proposed destination (or walk in at AAA offices), and the club will return a map marked with the most direct or the most scenic route, as you prefer. AAA, Mobil, Exxon and others also offer U.S. atlases and regional guidebooks to attractions and accommodations.

About 25 percent of the Ford Auto Club's 130,000 members routinely use the route planning service, said Leo Larkin, a club spokesman.

Supplementary travel benefits include rental car discounts; hotel and motel discounts; accidental death insurance; and quarterly travel-related magazines, such as Ford's Fair Lanes.

Most clubs also have their own special benefits: Ford members sometimes get discounts on Ford parts and accessories; Allstate members can cash checks at Sears outlets nationwide; AAA charges no fee for American Express travelers checks and operates full-service travel agencies in 815 of its 1,050 offices.

The cost of membership varies according to the club. On the low side is the American Association of Retired Persons Motoring Plan at $29.95 for member and spouse. On the high side is AAA-Potomac, which charges $46 for the first year and $36 for subsequent years for the member only. An associate membership for your spouse is $18; the charge is also $18 for each child. Members are covered for whatever auto they are driving.

AAA membership costs vary throughout the country, depending on the region. Some are higher than the Washington area and some are lower. Most other clubs set one national fee. Some, however, do not offer memberships for dependent children who are of driving age. Several clubs allow you to charge your membership to their charge card.

Is membership in an auto club worthwhile? That depends a lot on your mechanical skills, the age of your car and if you see emergency road service as the principal benefit.

Perhaps not, if you are what Amoco's Rudy Murcinko described as the "self-reliant" driver, "a person who can fend for himself." A good amateur mechanic, able to make his or her own repairs, certainly would fall into that category.

You might also find the emergency services unnecessary if you keep your car well-maintained, drive mostly new cars or have no history of requiring start-up or road service.

On the other hand, many drivers join AAA for "peace of mind and reassurance," said spokesman W. Allan Wilbur in the club's Falls Church headquarters. They like the idea of having someone obligated to show up if a malfunctioning car has stranded them.

Auto club managers point out that in this day of self-service gas stations many drivers are not giving their cars proper care, which means the cars may be subject to more-frequent breakdown. And with the high price of new vehicles, many Americans are holding on to the family car longer. Older cars, as their drivers unfortunately learn, tend to experience increasing problems as they roll up more miles.

If all you want from a club is emergency road assistance, it could take one to two calls a year for your membership to pay for itself. Call Carl, a Washington towing service, charges $15 to give your car a jump start. The basic cost for towing is $25 plus $1.50 a mile. That compares to annual auto club membership fees of about $30 to $50.

How fast a tow truck shows up depends on the demand for road service, according to auto club managers. A big snowstorm or an uncommonly cold morning could mean you are in for a long wait, whether or not you belong to an auto club.

Beyond emergency road assistance, drivers considering auto club membership should ask themselves how often they might use the other benefits. Will they read a quarterly magazine? Would it be helpful to have somebody plot a tour route? Will they use car-rental or hotel and motel discounts? Do they need additional accidental death coverage beyond any other coverage they may already have? Is payment of hotel and meal expenses comforting if they have to wait for repair of a car damaged in an out-of-town accident?

Apparently, many of these benefits are attractive. About 80 percent of AAA-Potomac's membership take advantage of its tour-routing and other travel-assistance programs, according to spokesman Douglas Neilson.

If you are considering a membership, ask for an application from several clubs. Then compare the benefits offered, the amounts reimbursed and the annual cost. Pick the club that offers you the best deal for the benefits that are most important to you.

Among the major U.S. auto clubs:

Allstate Motor Club: Special benefits include emergency check cashing at Sears outlets; an accommodation directory with 14,000 listings with prices guaranteed (or the club pays the difference); and a road atlas. The club reimburses you up to $50 for emergency road help. The annual fee is $32 for member and spouse. For information: 34 Allstate Plaza, Northbrook, Ill. 60062, (800) 323-6282.

American Association of Retired Persons Motoring Plan: Membership in AARP is open to individuals 50 years of age and older for an annual fee of $5. As an AARP member, you are eligible for the Motoring Plan at an annual rate of $29.50 for two adults. Emergency road assistance is provided through Amoco's network of service facilities. Plan members get up to 20 percent discounts at participating Holiday Inns. For information: AARP, 1909 K St. NW, Washington, D.C. 20049.

American Automobile Association/AAA-Potomac: AAA and its affiliated members probably offer the largest array of traveler services, available at 1,050 offices throughout the United States and Canada. The local club, AAA-Potomac, has full-service offices at 1825 I St. NW and in Wheaton Plaza, Falls Church, Alexandria and Manassas. The offices provide full travel-agency services, sell travelers check's, issue the international driver's license, route individual motoring trips, distribute AAA regional guides free to members and assist in the preparation of passport applications.

The local club has 83 service facilities with 370 trucks on contract to offer emergency road help. A membership is $36 yearly for an individual (plus $10 for the first year) and $18 each for associate members in the family. For information: 8111 Gatehouse Rd., Falls Church, Va. 22047, (703) 222-6671.

Amoco Motor Club: Amoco is perhaps AAA's major competitor; like AAA, it also dispatches emergency assistance trucks from its own network of facilities in the 48 continental states. Amoco also offers a variety of travel benefits, including trip-routing. The fee is $34.95 a year for member and spouse and $19.95 for each additional member of the family. You don't have to be an Amoco charge-card holder to join. For information: P.O. Box 9043, Des Moines, Iowa 50369, (800) START-UP.

American Express Driver Security Plan: The American Express plan is available to its card holders. Many of the travel and emergency assistance benefits are provided through the Amoco Motor Club. The cost is $33 a year for member and spouse. For information: American Express green-card holders, (800) 528-4800; gold-card holders, (800) 327-2177.

Chevron Travel Club: Currently Chevron has about 360,000 members, but it is soliciting the 100,000 members of the Gulf Auto Club, which goes out of business March 31 as a result of Chevron's purchase of Gulf Oil. Membership is open to Chevron/Gulf charge-card holders. If you require emergency road help, the club will reimburse you up to $40. Trip-routing, a 96-page atlas and most other travel-related benefits also are offered. The cost is $3 a month for an individual or $4 a month for a family. For information: P.O. Box P, Concord, Calif. 94524, (800) 227-1677.

Diners Club Motor Plan: The travel and emergency benefits are provided through the Amoco Motor Club to holders of personal (not corporate) Diners Club cards. If an authorized facility is not available, members can call one of their choice and will be reimbursed up to $35. The cost is $45 a year for member and spouse. For information: (800) 334-3300.

Exxon Travel Club: Exxon was organized in 1964, primarily to offer travel-related benefits to Exxon card holders, including lodging guides and trip-routing. About five years ago, it added emergency road assistance, and now the club is open to the general public. Members are reimbursed $50 for emergency road assistance. The cost for travel benefits only is $2.25 a month for an individual, $2.75 for a couple and $3.50 for a family. Emergency road assistance is an additional $1.25 a month. For information: P.O. Box 3633, Houston, Tex. 77001, (713) 680-5723.

Ford Auto Club: Anyone can join but most of the 130,000 members own a Ford vehicle. The club has been growing since Ford recently began selling auto club memberships through its car dealerships. Ford offers the a full range of emergency help ($50 reimbursement) and travel benefits, plus the occasional opportunity to buy Ford parts and accessories at discount. The cost is $39.95 a year for member and spouse. For information: P.O. Box 224688, Dallas, Tex. 75222, (800) 348-5220.

Mobil Auto Club: Along with the standard travel and emergency ($60 reimbursement) benefits, members get a copy of one of Mobil's very popular annual regional lodging guides. The first year you get the guide for your region; afterward, you can request any region. Membership is open only to Mobil card holders. The cost is $36 a year for member and spouse. For information: P.O. Box 5039, North Suburban, Ill. 60197-5039, (800) 621-5581.

Montgomery Ward Auto Club: At 1.5 million members, Montgomery Ward is one of the largest auto clubs, offering most of the standard travel and emergency benefits. It reimburses road assistance at up to $75, one of the highest amounts. It provides a 24-hour toll-free number to explain benefits should you need them in an emergency. The cost is $45 a year for member and spouse and $12 a year for all children. For information: 200 North Martingale Rd., Schaumburg, Ill. 60194, (800) 621-5151.

Shell Motorist Club: Membership is open only to Shell charge-card holders. The club provides travel and emergency benefits, including up to a $75 reimbursement for emergency road assistance. The cost is $39 a year for member and spouse. For information: 6001 North Clark St., Chicago, Ill. 60660, (800) 331-3703.