Highway News Roundup, Fall 2021

E-ZPass Electronic Toll Interoperability is Now Here

As I’ve written about several times before, there was a 2012 federal mandate to have electronic toll collection be interoperable nationwide by 2016. In practical terms this would mean you’d be able to use your same toll transponder to pay tolls nationwide. That deadline came and went without the country achieving full interoperability. Nevertheless, slow but steady progress has been made.

There are two facets to interoperability: the systems have to be able to read tags from other systems, and additionally each agency has to sign agreements and have their back-office systems linked up. For example, Minnesota used a different system than California, Illinois or New York, so interoperability was not possible. On the other hand, Minnesota for several years has used the same system as Texas, Oklahoma, Kansas, Florida, Puerto Rico and Atlantic Canada, but has never bothered to sign an agreement with any of them.

With respect to electronic compatibility, things have settled down so in North America there’s basically one older electronic system and two newer passive ones. The E-ZPass group, covering much of the Midwest and East of the country uses a system with active battery-operated, electronic transponders. Meanwhile states that are isolated from E-ZPass or implemented tolling afterward use one of two more modern, cheaper systems that use passive, battery-less RFID transponders, basically just a sticker with one integrated circuit and an antenna.

Minnesota has had multiple channel readers on the roadway with the theoretical capability to read E-ZPass transponders for a couple of years now, ever since the switch to the sticker tags from the old active Telematics transponders. But E-ZPass has shown no inclination to require or even encourage it’s three dozen agencies to install multi-channel readers to accept sticker tags. So, states like us that want to join E-ZPass need to revert to issuing expensive, battery-operated electronic transponders. The sticker tags still work and stay in circulation, but all new tags will be E-ZPass.

Here’s a progression of maps showing how the situation has evolved since I first started covering it. Georgia is planning to join E-ZPass soon, so the remaining yellow will turn purple and we’ll be left with two major interoperable blocks in purple and blue, and the isolated systems in brown (graphics by author).

US Toll Interoperability 2015.
US Toll Interoperability 2015.
 US Toll Interoperability 2020.
US Toll Interoperability 2020.

By 2020, except for the Laredo international toll bridges, all the Texas, Oklahoma, and Kansas agencies had linked up. The situation in Orlando was complicated, the Central Florida Expressway Authority (CFX), Florida Department of Transportation) (FDOT), and Florida’s Turnpike Enterprise (FTE) all operate toll roads there, with a road often changing ownership at a random exit. CFX (branded E-Pass) accepted E-ZPass while FDOT and FTE (branded Sunpass) did not. You couldn’t drive from the airport to Disney or the beach with E-ZPass.

With both Minnesota and the remainder of Florida having joined E-ZPass, here’s the situation as it is currently. As a side note MnDOT has decided to retire the MnPass brand in favor of the generic E-ZPass, while Florida has kept their E-Pass and SunPass branding.

US Toll Interoperability Fall 2020
US Toll Interoperability Fall 2021.

Here is the much simplified map to be effective soon; Georgia has announced it intent to join E-ZPass. Of note South Carolina and Toronto use E-ZPass compatible equipment and could join just by signing an agreement.

US Toll Interoperability 2022
US Toll Interoperability 2022.

The Connected Corridor

In fall 2020, a demonstration project for the next evolution of traffic signal controllers was completed. Traffic signal controllers have evolved over the years from simple electro-mechanical timers, to microprocessor controlled electronic devices, and now the newest ones are capable of running custom software and being linked to central systems through fiber optics. The newest evolution is Adapted Traffic Signal Control (ATSC) where traffic signals communicate with each other and additional sensors to provide some artificial intelligence to the network. For example, a traffic signal might tell another one down the road that an unusually heavy volume of traffic is heading its way so it should plan on lengthening the next phase.

The next step beyond that is traffic signals that actually communicate with vehicles. That’s what the Highway 55 “Connected Corridor” was about – a demonstration project to test out the technology and get an idea what challenges might be faced with a widespread implementation.

The Connected Corridor project was a three-year project to help the Minnesota Department of Transportation (MnDOT) advance the future of transportation. The project included the planning, design, deployment, and operation of connected vehicle technologies – including software systems and infrastructure to understand how to plan and prepare for emerging transportation technologies. This project included vehicle-to-infrastructure (V2I) technology, which helps vehicles “talk” to infrastructure to improve safety and efficiency of roadway users.

MnDOT Connected Corridor Summary Report, 2020

As part of an ultimate setup, in addition to sensing how many cars and where they are, things like speed and turn signal use can be communicated to the signal from cars and logged in order to help traffic engineers. In turn the signal could communicate to the car how much longer the red light will last (if the signal knows), which the car could then display to the driver or maybe even shut off the engine if the light will be red for an extended time. This demonstration was much more modest though, due to budget limitations and lack of “connected” vehicles. The only functional implementation was signal priority for snow plows at select intersections.

Connected Corridor. Photograph: Author
Close-up of connected corridor Transceiver. Photograph: Author

Full Connected Corridors or even widespread implementation of ATSC are probably some years away, but the groundwork is being laid as most new controllers installed are ATSC capable. In my home city of Bloomington, most city-owned signals have been upgraded and linked to each other and the city public works building via fiber. A county project to string fiber to all the signals along Old Shakopee Road is also underway.

Highway 74 Reverts to Gravel

On four miles of Highway 74, from Elba to County Road 30, an unusual “deconstruction project” took place. Crews came out, removed the badly deteriorated pavement and then left gravel behind permanently. Unpaving lightly travelled roads has been a thing both in Minnesota and across the country: the 40-year lifecycle cost for a paved road is roughly three times that of a gravel road. But this is the first it has been applied to a Minnesota trunk highway. The road is extremely lightly travelled; annual average daily traffic (AADT) is 400, and there is no money for reconstruction. This joins a seven-mile-long gravel section from County Road 20 to near US 61 at Weaver.

Highway 74 is the last state trunk highway to include a gravel section, due to very low traffic volume (the existing gravel sections are AADT 75) and the difficulty maintaining pavement deep in a ravine. Most of Minnesota’s trunk highways were paved by the 1950s, but a few sections of gravel remained in the northeast and southeast until the 2000s, the penultimate being a section of MN 65 through the Bois Forte Indian Reservation.

Deteriorated section to be returned to gravel
Deteriorated section that was returned to gravel. Source: Google

About Monte Castleman

Monte is a long time "roadgeek" who lives in Bloomington. He's interested in all aspects of roads and design, but particularly traffic signals, major bridges, and lighting. He works as an insurance adjuster, and likes to collect maps and traffic signals, travel, recreational bicycling, and visiting amusement parks.

12 thoughts on “Highway News Roundup, Fall 2021

  1. Sheldon Gitis

    Does anyone have any idea how much money has been spent building, maintaining and operating the MnPass/E-ZPass highway lanes and Electronic Toll systems, including the costs for law enforcement and cleaning up the mess from the crashes the additional lanes generate, and how much revenue the toll lanes have generated?

    What percentage of all the vehicles on 394 and 35 and any other MnPass/E-ZPass highways are equipped with transponders, and how much has MnDOT spent building and maintaining highway lanes for this, I suspect, relatively small group of drivers of transponder-equipped vehicles?

    1. Nate

      As far as I know, Minnesota does not have Toll-only roads, like most of the other states that have EZPass.
      Minnesota’s tolling is only used as an augmented use for HOV Lanes.

      So cost for infrastructure for building, maintaining (and the extra crashes?) are only somewhat offset by the fact that the lanes are primarily intended as public transit expressways, with HOV personal vehicles being a way to extend the capacity of those lanes (and encourage behavior modification for trips) and finally the toll infrastructure is a way to further extend that capacity and generate revenue for those that want the transponders.

      The lanes aren’t purpose built to be toll lanes, but it is a fair question to ask if the tolling is paying for the transponder infrastructure.

      I don’t have answers to EZ pass revenue, but here’s some DOT data on intended usage of the lanes- the interesting parts to me being that the lanes are regulated to flow at speeds higher than 45mph 90% of the time during peak travel time, as well as the fact that there’s a significant difference in average travel times in travel time for HOV lanes vs. Non HOV lanes. This page also shows that the bulk of the income from transponders has to first pay for the transponder infrastructure, then road/infrastructure costs get the remaining.


      1. Sheldon Gitis

        Apparently we agree, “it is a fair question to ask if the tolling is paying for the transponder infrastructure.” So if it’s a reasonable question to ask, why hasn’t it been answered?

        The toll of the tolling is a lot more than just “transponder infrastructure.” The costs of the tolling include, at least a portion of, all the construction, maintenance, land use, and patrolling costs of the additional lanes of traffic. The fact that the transponder-equipped private vehicles share the lanes with buses doesn’t make the lanes any less expensive. The HOV lanes would be less expensive if they only carried HOVs, with no transponder-equipped private vehicles requiring some mysterious “transponder infrastructure” of indeterminable cost.

    2. Monte Castleman Post author

      That’s an interesting question and I don’t know the answer. Very early on I read that the system was operating at a loss. I’m not sure if it’s still true, or if it included such things amortization of the initial capital expense and additional wear and tear on the roadway, or only ongoing operational costs.

      It’s notable that in the past few years the entire electronic infrastructure had to be replaced; new multi-channel readers to allow an orderly phase-out of the old Telematics transponders (and to comply with the upcoming national interoperability mandate). Now new E-ZPass compete transponders and a new back-office system to comply with that mandate. And replacing all the overhead signs with electronic ones to read “Express” instead of “HOV” lane and removing the diamond pavement markings and installing new overhead signs, including electronic ones to indicate who is currently allowed to use the lane, to comply with the new MUTCD.

      1. Sheldon Gitis

        When it comes to paving and maintaining additional highway lanes, it appears the only cost consideration is how much the Highway Dept. can get and spend.

        Charles L. Morohn, former traffic engineer and creator Strong Towns, explains how the racket works in his recent book, Confessions of a Recovering Engineer. As Morohn describes it, there’s basically 4 considerations: safety, cost, speed and volume. For the traffic engineers, the goal is increased speed and volume. Safety is ignored, and the only cost consideration, is ass-backward – making the project as costly as is possible. So the signage and electronics and “back office’ computer systems and transponder-equipped vehicles for a handful of suburban commuters to bypass the riff-raff in the toll-free lanes are added to the HOV lanes.

        The additional lanes do not to make the highways any safer or less costly, but rather, make them the money black-hole cluster-fuck nightmare they are.

  2. Brian

    400 vehicles per day seems to be plenty to justify a paved road. There are plenty of suburban residential streets with well under 400 vehicles per day that are paved.

    Now, I recall that this highway has soil conditions that make maintaining pavement very expensive.

  3. Mike Hess

    Monte, in your research did you learn how the MnPass figures out if you are in the lane with 2+ passengers and deserve to ride for free, or if you should pay with your transponder? I noticed last weekend heading up 35W in the HOV lane that when I passed a sensor/transponder on the side of the road it would flash – picking up my EzPass I bought years back for our road trips back east? But since I had car full of people I shouldn’t’ have to pay, right? how does it decide/know?

    1. Brian

      MNDOT sells a transponder that can be turned off when you have 2+ people in the car. There are also foil bags that transponders can be placed in so they won’t be detected.

    2. Monte Castleman Post author

      So, the basic answer is “it can’t / doesn’t”

      Minnesota issued MnPass / E-ZPass transponders (as well as Virginia and North Carolina, where they use E-ZPass and have HOT lanes) include an user activated on-off switch. With the active transponders it’s an electric switch that disables the electronic circuitry, with the sticker tags it would physically move the passive IC into a shielded compartment. None of the other E-ZPass agencies issue tags that can be shut off because they don’t have HOT lanes, only full time, any number of occupant toll roads and bridges.

      You’re not the first person that’s noticed they’ve been incorrectly charged when an out-of-state EZ-Pass that they may have had for years, intended for use only on road trips out East, suddenly and unexpectedly started getting hit by the Minnesota readers. The official line on what you’re supposed to do if you’re carpooling on a Minnesota E-ZPass lane with a non-switchable transponder is to remove it from your windshield and place it in a rf shielded bag (or just remove it from the car). For people that carpool regularly in Minnesota and travel to other states it probably makes sense to close the out-of-state account and get a switchable Minnesota issued transponder, especially since we’re one of the agencies that doesn’t charge fees for maintaining an account.

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