It seems like it'd be logical to make these kinds of agreements upfront: Maryland can't collect $ in tolls from out of state residents

The Washington Post reports ("Out-of-state drivers owe more than $137 million to Maryland. The state wants to recoup the unpaid tolls") that Maryland has millions of dollars in uncollected road tolls assessed on cars registered in other states.  

Maryland moved to cashless tolls, and people without an EZPass transponder are mailed a bill.  But while Maryland residents can be fined and lose their license for not paying, the State has no similar recourse against nonresidents.

The article states that Maryland Transportation Authority is considering selling the debt to private debt collectors, while some elected officials are suggesting that the state agency ink reciprocity agreements.

The article reports that some states have reciprocity, like Pennsylvania with Delaware, so that they can collect tolls across borders.  

And that Virginia's system requires EZPass transponders, making collection easier, but Maryland doesn't.

A few years ago, Congress mandated inter-operability for all the various toll pass collection systems.  Although the hoped for deadline of 2016 has long since passed ("Unifying our toll road systems," WJLA-TV).

And many of the systems are multi-state, like EZPass, which has 19 member tolling agencies in the Northeast and Mid Atlantic..

But wow, if you know from the outset that a goodly number of users will be from out of state, why not create inter-state collection compacts at the outset?

And inter-operability in tolling and collection systems.

It's an amazing example of planning failure.