I meant to include a pdf of the new law, here it is attached.

I was involved in the Legislative discussion when this bill was presented, and got to try to straighten out some of the problems with it.  (Unfortunately I was not entirely successful!)  Here is a link to the final version of the law as posted on the Statute Search web page:  https://legislature.maine.gov/legis/statutes/23/title23sec3121.html

The original intent of 23 MRS 3121 was to provide lenders with some sort of assurance that when they financed the purchase of a home on a private road, there would be some mechanism in place to insure that the access to that home would remain passable.  Where there is already a road association established under 23 MRS 3101, or even any sort of informal maintenance agreement, this law does not apply.  It only kicks in where there is no provision for maintenance.  If the abutters cannot come to any sort of agreement, the "default" position that kicks in is that each landowner pays an equal share.

The intent of the new law was to fill the gap where 3101 does not apply because there are fewer than four benefited properties, or where no road association has been formed.  In such cases, lenders may refuse to approve a mortgage.  They borrowed language from a law in another state that supposedly has been working well, that is to say, it satisfied the lenders.

But as originally worded, the proposed bill conflicted with 23 MRS 3101-3104.  It also used the ambiguous and outdated term "private way," which does not refer to privately owned roads, but to a class of roads now known as "public easements."  Since public easements are open to pretty much unrestricted public use by foot or motor vehicle, forcing abutting landowners to maintain the road for public use at private expense would raise serious questions of constitutionality.  This is mainly a problem on abandoned and discontinued roads, not private roads, so we got them to change the term from "private way" to "private road."  Therefore it should not be applied to abandoned or discontinued roads, but apparently not all realtors understand that.

An early version of the bill required only residential properties to share in maintenance.  In a state with a thriving logging industry, that could leave the owners of  residential properties bearing the entire cost of maintenance, while log trucks could use the road with impunity.  (I also know of cases where a gravel pit uses a private road, and they would also have been exempt.) We pushed to get ALL landowners to share the cost of road maintenance, and they did change the first line of the law to include all landowners.  Unfortunately, farther down the first paragraph it still says, "each residential property owner" shares the cost of maintenance.  Also, when that part of the legislation was changed, they also changed the part on Enforcement, so that instead of allowing a landowner to sue any other non-paying landowner, it now only says that the non-paying owner of a residential property can be sued.  So I already know of one case where the buyer of a residential property was assured the abutters would share the cost of maintenance, but it turns out that none of the other properties are residential, and none of them will pay.  This is a case not only of misapplication of the law to a discontinued road with a public easement, but also of failure of the law to require the non-residential properties to share the maintenance.

Does this law apply to discontinued town roads that the town has abandoned maintenance on that the town retains a public easement over?

No.  At least, it is not supposed to.  When I testified on this bill, one thing I was adamant about was that it should apply to privately owned roads, NOT to public easements.  I told them that was a can of worms they didn't want to get into, as it raises questions of the Constitutionality of forcing private individuals to maintain a public road at private expense.  So they used the term "private road" instead of the confusing and obsolete term "private way," which is defined in 23 MRS 3021 to be a public easement.  Unfortunately, I know of one situation where a property was sold and the buyer was told the access was a private road and that the abutters shared the maintenance.  Only it turns out it's actually a public easement, it has been designated as an ATV and snowmobile trail, and none of the other abutters will agree to pay anything towards maintenance to support the public uses of the road.

Or does it apply only to private roads such as private easements that are shared?

It is intended to apply only to private roads, that is, roads that are privately owned and maintained, and over which the owner can restrict access.

Does it apply to a deeded  easement over someone else's property that is only shared between the dominate and burdened estate? In other words does this obligate the burdened estate to share in maintenance that the dominate estate is using?

That's an excellent question.  The statute begins, "If more than one property shares a common benefit from a private road..."  I would say that if the burdened estate also uses the easement for access, then the owner should share in the maintenance.  However, if the easement is only used by the dominant estate, it would essentially be a private driveway, not a shared private road, and therefore this law would not apply.  (Disclaimer - I am not an attorney.  This is just my personal opinion.)