JULY 19 — If you’re planning on vacationing in Europe this summer, recent headlines may have prompted some questions. Does the weakened euro, partly the result of the fiscal crisis in Greece, affect whether you should put charges on your credit card in euros or in dollars? Is it legal and safe to use Uber in the wake of protests by taxi drivers throughout Europe, particularly in France where drivers have recently blocked roads to airports and set tires on fire? Do the International Air Transport Association’s efforts to implement more universal carry-on guidelines mean the time has come to buy a smaller roll-aboard bag?

Here’s what you need to know.

1. Should you make charges in euros or US dollars?

You’re asked at a hotel or restaurant if you would like to pay in euros or dollars. What do you say? In general, always choose the currency of the place you’re in. It’s not uncommon for there to be a markup on the currency conversion rate. Even worse, if you pick your home currency you’re typically socked with a service fee known as a dynamic currency conversion fee (or DCC), which can add up to an additional 2 per cent, 3 per cent, even 6 per cent or more, of your bill.

Eager to pay in dollars because you want to know right then and there how much you’re spending? Resist the urge and use a currency converter app such as XE (xe.com/apps) instead. Do it often enough and you’ll have saved enough money for a little shopping spree.

As for travellers planning to visit Greece, it’s possible there may be a few hurdles. In recent weeks some ATMs ran out of cash, resulting in long lines at others. On the other hand, the dollar is strong, making the islands even more alluring to US tourists.

2. Is it OK to use Uber?

Uber, the digital car-hailing service based in San Francisco, has clashed with regulators throughout Europe including the Netherlands, Spain, Italy and Germany. In France, the situation has been particularly incendiary. Taxi drivers have demonstrated from Paris to Marseille in protest of UberPop, Uber’s low-cost service, in some cases becoming physically violent with drivers they thought worked for Uber.

Unlike France’s taxi drivers, UberPop drivers are not required to have professional chauffeur’s licenses. Indeed, the French interior minister, Bernard Cazeneuve, called UberPop illegal. The service is suspended while Uber contests the law in a case pending before the French Constitutional Court. (There won’t be a resolution until the fall.)

While the government said it’s not legal to use UberPop, it is legal to use UberX, which in France is a black-car service that includes vehicles like a Mercedes-Benz C-Class and a Peugeot 508, as well as other forms of Uber there (like UberVan), whose drivers have professional licenses.

Still, be sure to pay attention to the local news. If there are more demonstrations, you may wish to stay out of the fray by taking the Métro (or a long walk) instead.

To find out if any of Uber’s services are available in the city you’re visiting, simply open the app on your smartphone. If service is available, you’ll automatically have the ability to request a car. Just be aware that in many cities in the United States there are low-cost Uber options in addition to black-car service, but in some European cities black-car service may be the only option - so expect to pay more.

3. Do you need new carry-on luggage?

In June the International Air Transport Association (IATA), which represents members of the airline industry, put forth industry-wide guidelines for cabin baggage on aircraft with 120 or more seats.

The new preferred bag size, the group said, would be 21.5 by 13.5 by 7.5 inches, smaller than the common 22-by-14 by-9-inch bags many passengers have. Soon travellers would be able to buy these smaller carry-on bags, which would come with an “IATA Cabin OK” logo. The association said it would not make Cabin OK logo tags available to travellers with bags that already meet the guidelines. Consumers would have to shell out for new bags if they want the Cabin OK designation.

Buying the bags would be voluntary, the association said. But passengers who choose not to get the new luggage could face uncertainty as to whether their bag would remain on-board a participating airline if the overhead bins were full. That’s because OK Cabin bags would theoretically be given priority to stay on-board in the event that not all carry-on bags could be accommodated. I say theoretically because, ultimately, the airline would still have the right to check any bag. In other words, there would be no absolute guarantees for anyone. Individual participating airlines could choose to implement the guidelines however they see fit, including allowing some larger bags on board.

Days after the initiative was announced, however, the association said it was halting the roll out “in light of concerns expressed, primarily in North America.” Still, you would be wise not to rush out and buy one of the roomier roll-aboard bags on sale in the United States right now.  — The New York Times