There are certainly enough signs on I93 and I95 explaining the tolls.
If you have EZ Pass, you are looking for those lanes.
If you don't know what EZ Pass is, you would be looking for a lanes that say cash.
If you don't have EZ Pass by choice, you will be looking for the cash lanes.
I firmly believe it is not a lack of clarity that causes problems, it is inattention. As I said on another thread on this subject, long before open road tolling, drivers would be in the far left lane, and at the last moment have to cut across three lanes of traffic to get to the cash lanes.
Perhaps if this is all too confusing for them, they may not want to be driving at all.