TRAVEL INSIDER : New Rates Help Avoid the Drop-Off Dilemma : Auto rental: As companies eliminate the charge for not returning a car to its original site, one-way trips are more affordable. But it still pays to compare prices.

For years, one of those annoying extras that could seriously inflate car rental costs has been the drop-off charge, the penalty you pay for returning the car to a location different from the one where you picked it up. If you were driving between two far-apart cities, the drop-off charge frequently could run as high as $900 or more.

Recently, several major car rental companies have acted to eliminate the drop-off charge for mid-size and full-size cars, making one-way rentals more affordable . . . and easier to arrange. Hertz, the nation’s largest car rental firm, announced its decision to do so in October. On a more limited basis, Avis, Budget and National also have taken steps to get rid of the drop-off charge on at least some one-way rentals.

That’s the good news. The bad news is that, despite the lower prices, a one-way rental still remains substantially more expensive than returning a car to the original rental site.

Still, the rental car companies are moving in the right direction. As one-way rentals become more affordable, vacation driving options increase.

Instead of being limited to circle itineraries beginning and ending at the same point, travelers can plan point-to-point drives over some of the country’s most scenic and historic routes.

One scenic drive well known to Californians is the rocky Pacific Coast from San Diego and Los Angeles north to San Francisco and Portland, Ore.. One of the nation’s most historic drives traces the famed Oregon Trail for 2,000 miles from Independence, Mo., across Wyoming’s South Pass to Oregon City, just south of Portland, or vice versa. In America’s heartland, motorists can tackle the length of the Great River Road, which follows the flow of the Mississippi River from Minnesota to Louisiana.

Under the new Hertz “One-Way Rates” plan, now available at all 1,500 of the company’s national outlets, travelers can pick up a mid-size rental car in Denver, keep it for a week and return it in Los Angeles at a daily rate of $68.99--which comes to a total of $482.93 (before taxes, any refueling charge and optional insurance). Until the new rates were introduced, a one-way rental would have cost $174.99 for the week, plus a drop-off charge of $900. Total: $1,074.99.

It should be noted, of course, that sightseers who cover the same itinerary but then backtrack to Denver to return the car could keep it for a full two weeks and still pay less than they would for a one-way rental. At the weekly rate of $194.99, a two-week rental, returning the car to the pickup site, would come to $389.98.

The car rental firms are aiming one-way rates at leisure travelers with the hope of attracting new business. Currently, only about 10% of the nation’s car rentals are on a one-way basis. For a long time, some car companies have offered one-way rentals without a drop-off charge in certain areas, such as within the states of Florida and California, and they have proved very popular.

In most other locations, however, rental firms over the years have imposed drop-off charges in order to cover what they say is the cost of returning a car to its original rental site. Often rental employees have had to travel by plane, train or bus from the car’s home base to the drop-off location, pick up the car and then drive it back. Or one or more rental cars might be shipped back by truck. The drop-off charge also is seen as a way to recoup the loss of revenue from a car that is out of service while it is being returned to its home fleet. Generally, drop-off charges are assessed on a sliding rate--the farther away the drop-off destination, the higher the cost.

But now changes in the industry, including computerization, have enabled Hertz and its competitors to keep much closer track of their one-way rental cars and, as a result, to cut their expenses in retrieving them.

These savings are being passed along to the consumer.

For example, Hertz has organized its one-way rental program so that in many cases, its customers actually are driving the cars back to the original rental site. Spokeswoman Annalise McKean-Marcus explains it this way: A customer rents a car in Denver and drops it off in Los Angeles. To get the car back to Denver, Hertz checks its computerized reservations system for a customer headed in that direction. One customer might take the car as far as Las Vegas, another might drop it off in Salt Lake City and a third finally get it back to Denver.

Hertz has limited its one-way rentals to mid-size and full-size cars, says McKean-Marcus, because they are better suited to longer drives.

Among the one-way programs with no drop-off charges--all with unlimited free mileage and rental taxes that are based on the tax rate at the pickup location--are:

* The Hertz Corp. Hertz’s rates vary by rental location, which might be a consideration in deciding where to begin and end a trip. For example, a three-day rental (mid-size) that is picked up in Washington and dropped off in Atlanta is $99.99 a day for a total of $299.97. If the car is rented in Atlanta and driven to Washington, the price is $68.99 a day for a total of $206.97.

Rates also vary by length of rental--one to two days, three to four days, and five days and up. The one-to-two-day rate is highest, and the daily rate drops in each of the two succeeding categories. For information: (800) 654-3131.

* Budget Rent a Car. About 300 of Budget’s 1,150 U.S. locations currently participate in the firm’s 3-year-old “One-Way USA” program, and others are expected to be added gradually. Unlike Hertz, Budget offers a standardized rate throughout the country.

With a seven-day advance reservation, a one-way rental is $89 a day for the first two days and $49 a day for each additional day. With a one-day advance reservation, the rate is $99 a day for the first two days and $59 a day for each additional day. The weekly rate, with a one-day advance reservation, is $399 with a rate of $49 a day for each day over seven.

Among Budget’s participating locations in the West are Los Angeles, Denver, Las Vegas, Reno, Seattle, New Orleans, Albuquerque and Portland. For information: (800) 527-0700.

* Avis Rent a Car. Introduced two years ago, the Avis one-way program is available at the firm’s 800 corporate outlets and at many but not all of its 800 franchise outlets. Rates are quoted on a daily and a weekly basis, and they can vary from location to location.

For a three-day rental, Avis currently is quoting a cost from San Francisco to Phoenix of $227; from Dallas to San Francisco, $237. For information: (800) 331-1212.

* National Car Rental System. National has experimented with a variety of one-way rental programs over the past five years, and about eight months ago it adopted the one now in effect, according to spokesman Michael J. Olsen. It is available at all of the firm’s 500 corporate outlets and most of its 500 franchises. Similar to the Hertz program, it offers rates that vary from location to location. For information: (800) 227-7368.

Each of the one-way rental programs is different, and comparison shopping is recommended. Price variations can be substantial.

On the Denver-to-Los Angeles itinerary, Hertz is quoting a one-week rate of $482.93. Avis beats it easily with a rate of $399. National’s rate is $464. And under Budget’s plan, the one-week rate is also $399. In each case, cars offered are typically mid-size models--i.e., a Buick Skylark, Ford Tempo, Chevrolet Lumina.

Depending on the rental firm, the rate at any of them may be slightly lower if you or your employer have a corporate account number, if you are a regular customer of one of the rental firms, or if you have an airline frequent-flier number. National, for example, offers a Denver-to-Los Angeles rental at $430 (instead of $464) to anyone who is a member of any frequent-flier program.

And you might also want to compare rates with rental firms that continue to impose drop-off charges. Sometimes the drop-off charge is low enough to make rental costs competitive. For example, Hertz is quoting the cost of a seven-day rental from Washington, D.C., to Seattle at $689.93 without a drop-off charge. In contrast, Alamo Rent a Car assesses a $300 drop-off charge, but its weekly rate is only $188.99, bringing the total coast-to-coast rental cost to just $488.99. Still, Budget beats both of them with its $399 weekly rate between the two cities.

Curiously, on a Denver-to-Los Angeles rental, Alamo doesn’t come anywhere close to being competitive with these same firms. It is quoting a drop-off charge of $1,500, and this doesn’t include the weekly rental rate. Spokeswoman Kathy Bradley says high drop-off charges such as this are meant to discourage one-way rentals to certain destinations where a one-way car cannot be put back into service quickly.