We have used EZ-Pass in many of the eastern states. It works well, you pre-load an amount on your account, and the system charges our cc an amount we set once our balance falls below a certain level. EZ-Pass (that we got in Florida) does not have any fees (you have to buy the transponder) whether the account is active every month or not. We recently signed up for the K-Tag system (no charge for the tag) which covers Kansas, Oklahoma, Texas, and some of Colorado (I've heard). This system isn't supposed to have any fees either. I believe you get a bill or notification of a bill and go in and pay it (we haven't used it yet so not 100% on that).
One other note... many toll roads are removing the pay booths and they just capture your license plate if you don't have a valid transponder/tag and either send you a notice or there are signs informing you that you must log into their website to get your bill.
An additional note, our EZ-Pass account allows us to change the license plate on file so we can move the transponder from one vehicle to another (K-Tag is a sticker and is for one vehicle only).