Description: 2020 Census block groups are clusters of blocks within the same census tract that have the same first digit of their 4-digit census block number; that first digit is the block group number. Block group numbers have a valid range of zero (0) through nine (9). Block groups beginning with a zero generally are in coastal and Great Lakes water and territorial seas. A block group usually covers a contiguous area. Each census tract contains one or more block groups and block groups have unique numbers within a census tract. Within the standard census geographic hierarchy, block groups never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urban areas, voting districts, congressional districts, and AIANNH areas. Block groups delineated for the 2020 Census generally contain 600 to 3,000 people.
Copyright Text: US Census Bureau 2020 TIGER/Line data from MAF/TIGER database (MTDB).
Massachusetts Bureau of Geographic Information (MassGIS), Executive Office of Technology Services and Security (EOTSS)
Description: This layer represents all the public and many of the private roadways in Massachusetts, including designations for Interstate, U.S. and State routes.Formerly known as the Massachusetts Highway Department (MHD) Roads, then the Executive Office of Transportation - Office of Transportation Planning (EOT-OTP) Roads, the MassGIS-MassDOT Roads layer includes linework from the 1:5,000 road and rail centerlines data that were interpreted as part of the 1990's Aerial Imagery project. The Massachusetts Department of Transportation - Office of Transportation Planning, which maintains the primary source for this layer, continues to add linework from municipal and other sources and update existing linework using the most recent aerial ortho imagery as a base. The attribute table includes many "road inventory" fields maintained in MassDOT's linear referencing system. See the Attributes section below for more details.The current MassGIS-MassDOT hybrid data layer was first published in November 2018, based on the MassDOT 2017 year-end Road Inventory layer and results of a 2014-2015 MassDOT-Central Transportation Planning Staff project to conflate street names and other attributes from MassGIS' "base streets" to the MassDOT Road Inventory linework. The base streets are continually maintained by MassGIS as part of the NextGen 911 and Master Address Database (MAD) projects. MassGIS staff reviewed the conflated layer and added many base street arcs digitized after the completion of the conflation work. MassGIS added several fields to support legacy symbology and labeling. Other edits included modifying some linework in areas of recent construction and roadway reconfiguration to align to 2017-2018 Google ortho imagery, and making minor fixes to attributes and linework. MassGIS continues to modify the layer as needed.This layer is named EOTROADS_ARC.From this data layer MassGIS extracted the Major Roads and Major Highway Routes layers.
Copyright Text: Massachusetts Department of Transportation (MassDOT), MassGIS