If you’ve ever been hit with a surprise fee when you rented a car or booked an airline ticket and found yourself saying, “There ought to be a law,” I have some good news for you: There is. Or at least, there could be.

There could be two laws, actually. The Clear Airfares Act is a Senate bill that would require airlines and online travel agencies to disclose any additional fees before you buy a ticket. And the End Discriminatory State Taxes for Automobile Renters Act would prohibit states or localities from collecting a discriminatory tax on motor vehicle rentals.

Just one problem: Neither of these bills has been passed.

A few weeks ago in this column, I explored which laws benefiting the traveling public trade groups hoped to see passed in 2010. To my disappointment, the travel industry seemed more interested in seeing Congress reauthorize the Federal Aviation Administration than pass laws that would actually help travelers directly, but that’s hardly a surprise. The reauthorization bills are loaded with amendments that help the trade groups’ members, so who can blame them?

But these proposed rules could make your next trip better, and they deserve our attention.

“Last year, airlines implemented a holiday surcharge on the busiest travel days during the holiday season and after, and I think consumers should be made fully aware if their airfare includes one of these surcharges,” said Sen. Robert Menendez (D-N.J.), who introduced the Clear Airfares Act.

It’s not just the holiday fees. The surcharges have spread to other times of the year, including Super Bowl weekend. When you book an airline ticket online, you don’t always see the total price until you’ve made a decision to buy. And even then, you don’t have an idea of the true cost of the flight until after you’ve shelled out more for luggage, a seat confirmation or early boarding privileges.

Menendez believes that fees should be disclosed before you buy.

“Trying to figure out everything that goes into your airfare is like a pilot trying to land a jumbo jet in a thunderstorm with no map and no electronic instruments,” he told me. “It’s possible, but it’s awfully tough.”

Why would airlines resist this kind of disclosure? Because leisure travelers are so price-sensitive that a fare difference of even a few dollars can affect their purchasing decisions. Some airline apologists have also pointed out that there are technological challenges to calculating a total fare, but I’m told that the latest reservations systems can handle Menendez’s proposed price rules without any trouble.

The car rental bill, which was introduced by Rep. Rick Boucher, a Virginia Democrat, would stop municipalities from collecting “discriminatory” taxes on rental cars. The taxes can add several dollars a day to the price of a vehicle, and often more. The car rental industry, which often finds itself in the awkward position of having to defend these indefensible surcharges, supports the proposed law.

“It limits taxes placed on rental car consumers to issues tied specifically to the operation of the rental car facility,” says Robert Barton, president of the American Car Rental Association, a trade group.

The car rental industry’s support for the bill isn’t entirely altruistic. If stadium and convention center taxes are removed, prices won’t necessarily fall. Car renters would probably pay the same rates, but more of the money would go to the car rental companies. Given the current state of that industry, this might not be a bad thing.

In the meantime, what can you do when you’re faced with a strange-looking tax on your car rental bill, or an odd fee on your airline ticket? Apart from writing a letter of complaint to the municipality where you paid the stadium tax, or firing off a missive to one of your elected representatives, not much.

Car rental customers have a slight advantage; at least their total rate is quoted upfront, including all the taxes. Airline passengers have to go fare-shopping with a calculator to get a real idea of how much they’ll pay for their flight.

I wanted to close by recommending a clever Web site where you can find the real price of a flight. But I haven’t heard of one, and several Internet searches led me back to my own Web site, where I lamented the impossibility of finding the real price of a ticket.

Maybe there ought to be a law.

(Photo: MaugiArt/Flickr Creative Commons)