This dataset uses the attributes described in the last paragraph as part of its creation. Of all MV roads from the MassGIS datasset, all those that were either unpaved, "neighborhood" or "local" were initially chosen. This subset was then refined manually to further limit the roads/records to those that appear to have limited evacuation routes and limited connectivity to a larger network.

In March 2021, the Martha's Vineyard Commission (MVC) added 3 attribute fields to this dataset. [MVC_Class] contains a numeric code for use in symbolizing the data for cartographic purposes. Based purely on local knowledge & perception of which roads are the main/primary roads (#4), secondary (#5), neighborhood (#6), and local roads (#33) are identified. The other attributes of [Surface] and [Surface_Source] indicates if a road segment is paved ("Y") or not paved ("N"). The source of that determination is indicated in the [Surface_Source] field. The determinations made by the "MVC 2021" are based on field observations or aerial photo interpretation. Some segments were split to accommodate a change in the road's surface within a segment.