Nationwide Electronic Toll Collection (ETC) Interoperability has been an elusive goal for some time. In practical terms that would mean you’d be able to use your MnPASS transponder to pay tolls on a road trip to Chicago or in your rental car in Florida, and in turn, residents of those states would be able to use their IPass and Epass to pay tolls on the MnPASS express lanes. There was, in fact, a 2012 mandate for nationwide interoperability by 2016. In 2015 MnPASS was still interoperable with no other states, so I wrote an article about the status of things. The deadline has long come and gone, but I recently noticed that MnDOT has announced their intention to become interoperable with the E-ZPass network as of summer 2021, so it’s time for an update.

Introduction to Electronic Toll technology

Electronic tolling is the idea that you can use a toll road or toll lane without stopping at a toll booth to pay cash; instead a transponder in your car communicates with an overhead reader on the highway and tells it to deduct the amount of the toll from the account you have set up. Originally these transponders were “active” – having batteries and electronic circuitry – and thus were relatively expensive for the agencies to buy. In the early 2000s there were a number of different active systems out there, but gradually states in the Northeast and lower Midwest have joined the E-ZPass network.

E-ZPass was originally a consortium of the toll agencies in New York, New Jersey, and Pennsylvania. These three agencies consisted of two-thirds of the U.S toll industry, so nearby states were motivated to join up by linking computer billing systems and if necessary, switching protocols. Some agencies maintain their own branding – Illinois State Toll Highway Authority calls theirs “IPass” for example – but henceforth I’m going to refer to the entire network as “E-ZPass”.

Meanwhile, states like Minnesota that were isolated from the E-ZPass block saw no need to be interoperable, and thus chose their own active technology. Minnesota (and Washington) used a system from an Israeli company called Advanced Telematics. The southern states tended to use Transcore, and California had its own standard, commonly called Title 21. Following this first generation of active transponders, newer technology was introduced in the form of passive RFID sticker tags. Although the readers are slightly more expensive, the transponders issued to motorists are much, much cheaper, essentially just a sticker with an antenna, a capacitor, and one chip as opposed to an active electronic device. Originally the standard was ISO 18000 6B (commonly called “SeGo” as branded by one of the companies that added proprietary security enhancements to it), then ISO 18000 6C.

States other than the E-ZPass group that introduced electronic toll technology, or switched protocols, as Minnesota was doing at the time of the last article, tended to use SeGO or 6C. (I saw a request for proposals for a 6C system, so in the prior version of my tolling technology map, I coded it as such, but a MnDOT person I subsequently spoke with indicated that they actually went with SeGo.) The large E-ZPass group shows no sign of switching to one of the newer, passive sticker tags, so we still have three completely different toll systems out there.

There are benefits to active transponders – they can beep to let the driver know a toll was read and paid, and the one formerly used by Maine would even display the account balance on a digital readout. But I think the barrier to E-ZPass switching is more bureaucracy, trying to get all those now dozen or so agencies to agree on something.

Here are simplified maps of the toll technologies in use at the time of my original article and today.

Barriers to Interoperability

Interoperability requires two components: first, there has to be an actual agreement between agencies linking computer systems. Second, there has to be a common protocol. I’m not an expert in computer systems, but I’m assuming the main obstacle is just finding the funding and political will to link all the dozens of different systems around the country together. Instead, I’ll focus on the protocol issue.

Things were still a mess in 2015, with seven different protocols in use. Today, except for Alabama and a few isolated bridges that still use RFID proximity cards, and thus really aren’t electronic tolling in the sense that you can drive through a gantry without stopping, there are now only three. This is significant because gantry readers that can read up to three different protocols exist.

A number of states, including Minnesota, have installed multi-channel readers as part of their plan to switch to newer protocols (as well as for future interoperability) The idea is to have an orderly phase-out of the old transponders by having equipment that can read both the old and new protocols.

Changes since 2015

Back in 2015, the toll agencies in Texas, Oklahoma, and Kansas, which have always used compatible equipment, were in the process of linking their systems together. That is now fully completed except for the city-owned Laredo international bridges. Interestingly, there was talk about the Texas / Kansas / Oklahoma block linking with Florida, which also used SeGo, but that apparently has stalled. The biggest push is for Florida and E-ZPass to link up, but talks have been going on for years without a clear path forward.

The main issue is that E-ZPass has gotten big enough that smaller agencies have no negotiating power. And most of the E-ZPass block have single-channel readers that can only read their own protocol, TDM, meaning they can’t accept Florida’s or Minnesota’s SeGo, and there’s been no encouragement from the group for agencies to install multi-mode readers on new or renovated projects. What’s more, many E-ZPass facilities have actual barriers that don’t lift unless a toll is paid on the spot. This precludes any sort of back-end “toll by plate” scenario where a photo of the license plate of passing cars without a TDM transponder is taken, and later matched to a valid account from another state for billing.

As a result, states that want to be compatible with E-ZPass are left with no choice but to issue active transponders that can do TDM, despite the added cost. North Carolina is doing so, and the Central Florida Expressway Authority has also started. When tolls were introduced on the Louisville area bridges, they of course wanted to be on E-ZPass, but from the start they also issued 6C stickers for locals that aren’t interested in using it on the E-ZPass network. Interestingly, South Carolina and Toronto use TDM equipment but show no inclination to link with E-ZPass.

Minnesota Joins E-ZPass

MnDOT is in the same dilemma as the Florida agencies. So once again, MnDOT will be issuing expensive active transponders, this time with the TDM protocol, to all new customers, and any existing customers that want one. I believe it’s likely these will be the same commercially-available dual-mode SeGo/TDM model that can be turned off when carpooling in an express lane that North Carolina issues. It’s unknown if there will again be a purchase or monthly charge for the much more expensive active transponders. North Carolina charges $7.49 plus tax for a dual-mode transponder (you can go to the website to virtually switch if off for carpooling) or $16.49 for one with a physical switch, the “flex” model. Like Minnesota, if you just want a sticker for non-E-ZPass use, it’s free.

I asked MnDOT why they’re making this transition now, as opposed to 5 years ago or 5 years from now, but I didn’t really get an answer. Five years ago, the response I got could be fairly characterized as “we’re ready when the federal government makes us.” Perhaps they decided that with the ongoing requests to be able to use it in Chicagoland, combined with the lull in interest locally due to the pandemic, it was time.

Until now I’ve never owned a MnPASS. Personally, I do not favor highway tolls. Like all user fees, sales taxes and the like, they’re inherently regressive, impacting the poor more than the rich. It makes no sense that governments build things like freeways, transit, and state parks that benefit society and then discourage society from using them by charging for them at the point of use. And in many cases, promises were made to the residents of states that tolls would be removed when the construction bonds were paid off. Kentucky kept their promise. Illinois and most other states broke their promise.

But my main reasons for not having an MnPASS aren’t philosophical; I just have no real use for it. I don’t like driving in traffic and then paying for parking. I’ve been able to avoid having to take a job downtown – I’ve always taken jobs in suburban office parks and now mainly telework. But now that I could use MnPASS on road trips to Chicago or when I rent a car in Florida, I’m likely to get one. Having to pay $50+ in inflated toll charges to the rental company for driving a rental car from Miami to the Keys because the Florida’s Turnpike Extension wouldn’t take cash was just galling to me. The Northeast, where I also travel from time to time, is also starting to go cashless, and soon my travels there would have become an issue without a compatible electronic pass. But not anymore.