You got me, let's tag the rest of the roadways on Aquidneck Island to trunk while we're at it, just because the page doesn't say not to.

It should be assumed that the trunk route begins/end where the route transitions into another of the same importance because roads are classified based on importance. The trunk route that links Newport to Fall River is described on the Wiki page as 'RI-114 / RI-24 / MA-24'. This means that it should follow Route 114 up to Route 24. You could make an argument that that's vague, as it could mean any section of Route 114, but the roads you tagged as trunk do not link Fall River and Newport. They are not part of the intended trunk route. 

You keep saying that these edits are based on your 'survey' but that could mean anything, and doesn't provide a real explanation for why you are making these edits.