Unless you have an unlimited budget, don't use your mobile data in the US! Proximus charges €14.52 per MB used there. This means that a connection of just a few minutes to mobile networks will literally blow up your bill.
However, your telecom operator (whatever it is) is obliged to block your Internet connection abroad when your data consumption reaches 60 euros outside the bundle. This limit can be increased or decreased on request.
Here are some solutions to limit your costs abroad:
Pocket Wi-Fi
Companies such as
mywebspot have specialized in renting a box that allows you to enjoy unlimited (secure) internet and a broadband connection in more than a hundred countries for as little as 5.4 euros per day.
In concrete terms, you must first reserve it online. The box is then delivered to you before your departure. On your return, simply return it in a pre-stamped envelope.
A simulation on this company's website gives a total amount of 255.30 euros for 27 days (9.45 euros/day). To this amount must be added the shipping costs (14.90 euros) and the return costs (9.90 euros), for a total amount of 286.10 euros. The car charger is optional and costs 6 euros.
Mobile data bundle
Proximus as well as other operators offer special packages for abroad. However, these may not be sufficient in your case. For example, the Proximus Daily Travel Passport option costs 5 euros/day of use. For this price, you have 80 MB/day at your disposal (in addition to an SMS and call pack). Since you are leaving for 27 days, this will cost you 135 euros.
With the other Proximus option, Daily Travel Surf, you have 100 MB/day at a rate of 17.99 euros/day. This means a total amount of 485.73 euros in your case. This is actually more expensive than the daily rental of the connected tablet offered by Apollo (10 dollars/day or 8.65 euros/day), i.e. about 234 euros for 27 days.
Free Wi-Fi
In the United States, the possibilities of free connections are very extensive. They can be found in hotels (which is not interesting in your case), campgrounds and most restaurants. As a result, you will often have to pay a drink to get access to them.
Moreover, this type of connection is rarely secure, which exposes you to possible hacking attempts.
Prepaid card
It is possible to buy a local prepaid SIM card when arriving in the United States. This can be used in your phone provided that it is "unlocked", i.e. your mobile phone is unlocked in case it has been locked by a mobile operator under contract. Your smartphone must also be compatible with US networks.
For the rest, "cards to top up your communication credit can easily be bought in mobile phone shops, supermarkets, CVS-type drugstores, petrol stations, etc.", according to the experts at Le Routard.
However, this is a formula not recommended by Axelle Blanpain, a lifestyle blogger who has already done a few road trips in the United States. "I had analyzed the issue of the prepaid SIM card and I never applied it because I always found it very complicated, especially since the rates applied are not the same from one state to another."
Offline plan
Applications such as Google Maps (iOS, Android) or TomTom Go Mobile (iOS, Android) allow you to access road maps in offline mode, provided you have downloaded them to your smartphone beforehand.
In fact, the GPS function of your smartphone can work without the need to activate cellular data. Please note that maps on TomTom Go Mobiles are available free of charge for a limited number of kilometres: 75. Once this limit has been exceeded, you will have to pay to continue using the downloaded maps: 5.99 euros for a month's use or 19.99 euros for a year. Google Maps remains 100% free.
In this regard, Axelle Blanpain recommends using TomTom Go Mobile rather than Google Maps for a road trip in the United States. "I've used both applications abroad and it seems to me that navigating via Google Maps doesn't work every time when cellular data is not activated on the smartphone. So I tend to use Google Maps when I need maps to get around in cities like New York or London for example."