Take a wild guess: Which of these will end up costing you the most money?

a) The road less traveled

b) The lost highway

c) The scenic route

The answer, of course, is that this is sort of an insane question. But since you were already willing to take the travel quiz, permit me to suggest that the correct response is actually:

d) the path of least resistance.

We as leisure and business travelers walk this path often, perhaps most famously at the car rental counter. Despite achingly precise language in rental contracts advising us that we may already have vehicle collision coverage through our credit card company or car insurance policy, many of us - largely because we’re unfamiliar with the terms or deductibles of our existing coverage - find it easier to buy the rental car company’s loss and collision coverage on the spot. In rental car lingo, we don’t bother declining the loss-damage waiver (LDW) or collision damage waiver (CDW). This adds up to millions of dollars we shell out needlessly to the rental car companies each year.

The thing is, most of us are aware we’re doing it. That’s what the path of least resistance is about. It tantalizes with its conveniences and amenities that we don’t necessarily need, want, use, or get.

Speaking of rentals

Pre-paying for your rental car’s tank of gas may seem like a good idea, especially when the rental company offers the street price for fuel. However, you should first ask yourself whether you’ll actually need a full tank. On many day trips or overnights you may only need half a tank or less, in which case you’ll have pre-paid for gas you didn’t use. Compare your rental’s miles per gallon against your projected round-trip driving distance before taking the option.

Also be wary if an electronic toll collection gizmo like E-Z Pass is mounted on your rental car’s windshield. It’s convenient for sure, but the first and only time I used one I was blindsided when the third-party vendor that provided the passes to the rental company not only charged me for the tolls but also surcharged me for using the pass. The charge runs about $2.50 a day, usually capped at $10.00 for a weekly rental.

Track your banking fees

You know to avoid ATM surcharges at home, but be particularly careful while traveling overseas, advises travel writer Lisa Davis, a managing editor at First Class Flyer. “I was in India and got charged $5 for every cash withdrawal,” Davis says. “I learned to either take a large amount of cash out at once or call my bank and negotiate the fees, explaining I travel internationally for business.” Davis says her bank told her that she could avoid surcharges if she limited her transactions to her home bank’s overseas partner banks, and provided her with a list of them before she left.

If you cruise, don’t lose

Once you book a cruise it’s not necessary, economical, or even more convenient to buy certain additional services facilitated by the cruise line, notes Karen Bauer, owner and operator of travel agency Interliner.com. “If you're taking a cruise and are considering the motor coach transfers between airport and pier, do a little research and some quick math,” Bauer says. “Almost always if there are at least two of you traveling together, it's going to be the same or less to take a cab. And that way you go when you want to go without waiting for 62 other people to board a bus.”

Avoid the room service trap

If the path of least resistance had snacks, you can be sure they’d be provided by room service. By now most of us are familiar with jacked-up room service menu prices and accompanying surcharges, but what if the kids have been buzzing about room service for weeks? There’s no reason in-room dining has to be provided by the hotel. “Call the hotel restaurant, pick up the order yourself, and take it back to your room,” suggests Traveling Mamas blogger and former flight attendant Beth Blair.

And if you do succumb to room service and its fees, be mindful not just of the service surcharge, but also of any pre-added gratuity. It’s all too common for guests to inadvertently add a tip on top of that, Blair notes.

Watch these other hotel fees

Upon check-in, speak with the manager and try to eliminate or reduce resort fees that may include “access to the tennis courts, fitness center, and even discounts at the on-site restaurants” that you and your family may never use, Blair says.

Frequent business traveler and AllBusiness.com blogger Ken Walker once got some money back “for a ‘mountain-view room’ in a Denver hotel whose ‘view’ was blocked entirely by the new hotel that went up across the street.”

And if you pay to use your hotel’s Internet access or valet parking once or twice, Walker urges scouring your bill upon check-out to ensure it doesn’t include a recurring charge for those services for every day of your stay. Speaking of the Internet, if you or your employer haven’t sprung for a cellular Internet laptop card whose usage fee almost always beats your hotel’s, Walker suggests asking for a guest room in proximity to any area of the hotel that might host a free wireless network, as you might be able to connect to it, rather than the hotel’s paid network, from the comfort of your room.

Kids in tow? Be first in the room and scout it for items that are for purchase. “My family stayed at a resort where golf hats and shirts were in the room,” notes Blair, “and if the item tag was removed it meant you wanted to purchase it. My kids instantly spotted the hats and began to remove the tags. [Fortunately] I caught them in time.”

Hotels are also getting more clever by positioning water and other snacks in odd parts of the room away from the mini-bar, so that guests don’t immediately associate those treats with potential costs until it’s too late. Don’t fall for it.

Guests make mistakes, too.

Hotels are also prone to introducing errors on your bill caused by other guests, notes Walker. All it takes is for a” guest to transpose a couple of numbers on his restaurant receipt and you're the one who will be charged,” he says.

He recalls one instance when a guest mistakenly “gave my room number as hers. I was charged $75 for a late night ‘Champagne & Cheese for two, with strawberries and tea.’ I’m six feet, 285 pounds, and fairly obviously from Texas. I looked the manager straight in the eye and asked him, ‘Do you think that's something I would order?’ They dug up the signed copy of the receipt, looked at the woman's name, apologized profusely, and took it off the bill.”