Remember the old days, pulling up to the toll collection booth and dropping some loose coins in the bin? Even at a young age (counting the endless line of vehicles in front of and behind us) I always marveled at the vast riches contained in those baskets.

Of course, it’s all automated now. Just about every major toll system in the U.S. has converted to cashless payments. But the digital transactions add up just as fast – and the rates haven’t gotten any cheaper.

Take the Dallas North Tollway, a heavily traveled artery that runs from downtown 30 miles north to the affluent suburb of Frisco. Depending on payment method and vehicle size, the fees typically range from $0.22 to $0.44 per mile – or about $7 to $14 from end to end. Double that for local commuters going to and from work each day.

Some of the high-volume segments see more than 50,000 cars and trucks passing through daily. That’s well over $2 million in revenues every 24 hours.

Most of the north Texas locals have transponders mounted in their vehicles that are linked to a prepaid TollTag account. Sensors mounted atop toll plazas read the devices as they pass below… and then automatically deduct charges as they accrue.

You might have similar technology installed where you live, perhaps under a different name like E-ZPass, FasTrak or SunPass. They all work about the same, invisibly collecting electronic payments day and night from every vehicle that crosses certain roads, bridges or tunnels — without the need (or expense) of attendants.

As for visitors without an account, most toll systems have automated technology that captures license plate images as they zip past cameras at 70 miles per hour. The driver is later billed the old-fashioned way: a mailed invoice. Following last month’s trip to Tulsa, I’ll soon be getting one courtesy of the Oklahoma Turnpike Authority.

If you’ve visited the Keystone State, then you’re probably well acquainted with the Pennsylvania Turnpike, which stretches the entire width of the state. Standard toll-by-plate rates have risen to 14.3 cents per mile (plus $2.26 per gantry passed).

A trip from Pittsburgh to Philadelphia runs about $70. Drivers who enter at the Ohio border and make the full 550-mile transit to the New Jersey side will rack up a hefty bill of $110 – even more for commercial trucks.

First opened in 1941, this multi-lane expressway accommodates 570,000 vehicles on an average day. That traffic load swells to 700,000 during busy holidays, like Thanksgiving. The average trip is 24 miles and racks up a bill of $7.84. That puts annual revenues near $1.5 billion (less $80 million or so for routine maintenance).

And rates generally increase about 5% to 6% annually.

Let’s just say there are less productive assets. If your portfolio has room for a tax-free municipal bond, the Pennsylvania Turnpike Authority recently issued $600 million in new revenue bonds whose principal and interest are backed by the system’s fees. They carry a solid AA- credit rating from Standard & Poor’s.

But I digress.

There are larger and more profitable toll transit systems. Those honors go to Florida and New York, respectively. Nationwide, there are more than 5,000 miles of pay-to-drive roads in 38 states from California to the Carolinas. Collectively, Americans make more than 5 billion trips on these stretches annually.

In fact, the United States leads the world in toll road revenues, edging out China. While that factoid will surely elicit groans from motorists, investors might have a different perspective.

Originally, this is where I planned to pivot towards metaphorical toll collectors that rake in steady cash flows. Like publicly traded airports, which pocket sizeable fees from every arriving and departing aircraft. Or title insurance provider Fidelity National Financial (NYSE: FNF), which acts as a tollkeeper for the housing market.

That was until I ran across a curious business whose toll-related profits come, quite literally, from tollways. After all, somebody must install all the camera and sensor infrastructure and handle the back-end payment processing. There are only a few large-scale vendors in this space.

The industry leader is New Jersey-based Conduent (NSDQ: CNDT), which provides a wide range of “smart mobility technology solutions” to government and commercial clients in more than 20 countries worldwide.

Just last month, Conduent was awarded a contract to implement a pay-by-plate collection system for the Richmond Metro Transportation Authority (RMTA). The agreement covers everything from imaging technology to payment processing.

This is the latest in a long line of business wins with state regulatory bodies: the Virginia Department of Transportation, The Ohio Turnpike and Infrastructure Commission and many more. Every day, it handles approximately 13 million tolling payment transactions on behalf of 600 different government transportation agencies.

That’s just one part of this multi-faceted business, whose client roster includes 4 of the top 5 automakers, 6 of the top 10 banks, 46 of the 50 states, and half of the Fortune 100. Other outsourced services range from simple customer service to government benefits enrollment and Medicare claims administration.

Across its various business lines, Conduent generates $3.2 billion in annual revenues. With high renewal rates (key clients have been on the books for 20+ years), most of this income tends to be recurring in nature. And thanks to meaningful margin expansion, EBITDA rose by more than 50% last quarter to $37 million.

I’d like to see further improvement in the free cash flow department. But the recent uptick in new business signings is encouraging. Beyond that, Conduent is sitting on a treasure trove of 500 U.S. patents (190 in the transportation sector alone).

A 30% pullback has discounted the market cap to just $370 million, which is less than last year’s pre-tax operating income of $504 million and just three times trailing EBITDA. At yesterday’s close of $2.35, you can pick up a few shares for just a handful of quarters.