Depending on where you’re visiting in the US, toll tags might be an unavoidable part of driving. Furthermore, it can be tricky to know which toll tag you need for what part of the country.
Back in 2012, Congress passed the MAP-21 Act, which required that by the end of October 2016, it be possible to have a single toll tag and account for all federally-funded toll roads in the US. There was no penalty for non-compliance, and no funding was provided, so it’s been slow moving.
Technically, this mostly happened in the form of NATIONALPASS for CA, DE, FL, IL, IN, KS, KY, MA, ME, MD, NH, NJ, NC, NY, OH, PA, RI, TX, VA, and WV. Unfortunately, NATIONALPASS has a monthly fee starting at $7.99/mo up to $50 in tolls per month and $10.99/mo if you spend more than $50/mo. This means that you’re paying about $8/mo for the privilege of being able to use it, even if you haven’t driven on a toll road.
Practically speaking, you can get a lot of the country with a couple of toll tags: E-Z Pass, the Florida Turnpike Enterprise hub, and the North Texas Tollway Authority hub.
For the E-ZPass network on the East coast, you can get one from any of the states or authorities that issue them and they all work together. Someone has helpfully built a comparison matrix here: E-Z Pass System Comparison.
I’d suggest the Massachusetts E-ZPass because the tag doesn’t require a deposit and there are no annual fees or non-usage fees. You’ll need a holder to be able to be able to move this tag between vehicles, so I suggest the JL Safety one.
For the North Texas system, I recommend the K-Tag that comes with suction cups. There is a sticker version, but it’s difficult to move between vehicles. Like the Massachusetts E-ZPass, you don’t pay anything for it when you’re not using it, though you’ll have to pay $25 for them to send you the movable one.
I don’t currently have a Florida tag, but with any luck, I can wait it out until one of the other networks interoperates with it.
If you’re looking to get a toll tag for one of these areas that aren’t in one of the big networks, hopefully it’ll become easier soon. I’d suggest going for a movable transponder if you can get one versus the sticker. If you don’t mind paying about $8/mo ($96/year) for most of the networks, the NATIONALPASS will get you there.