OVERVIEW

This datalayer represents the “major roads” in the Commonwealth from the Massachusetts Highway Department (MHD) Roads datalayer.  Four classes of road are included: Limited Access Highways (such as Interstates with on- and off-ramps as the only means of access), Multi-lane Highways without limited access, Other Numbered Highways (such as state and Federal routes that are not included in the previous two categories), and Major Road-Collectors (non-numbered routes that connect numbered routes).  These major roads are stored as one statewide coverage; the coverage name is MAJRDMHD and the STATE library layer name is MAJ_RD_MHD. In ArcSDE the layer is named MAJRDMHD_ARC.

Another statewide layer, MHDRDPTS (MHDRDPTS_PT in ArcSDE), is a point coverage that may be used for plotting route shields that have the look of those on actual highway signs (i.e. red, white and blue Interstate; U.S. shields; boxes for State routes). To plot these using Arcplot, use the markerset solidshld.mrk; a special font - fnt029 - must be located either locally or in the $archome/igl63exe directory. Issue the pointmarkers command and use the RT-ID (route number) or ART-ID (alternate route number) item, which matches the appropriate symbol in the solidshld.mrk markerset.

Download these files (hold down Shift key and click): fnt029 | solidshld.mrk

To plot these points in ArcView 3.x with appropriate route shield markers, do the following:

1. download a set of route shields created for Massachusetts by Jim Mossman of Data Deja View from the ESRI ArcScripts page.
2. Follow the instructions included in the .zip file for installation of the fonts onto a Windows PC.
3. download mhdrtid.avl, a MassGIS-produced ArcView legend file for symbolization
4. add the Route Location theme in ArcView and load the mhdrtid.avl legend, symbolizing on the RT-ID item.
5. you may want to adjust the size of the markers or select a subset based on the MARKER field to avoid too many shields plotting, depending on your map scale.

Please note that the locations of these points have been chosen to optimize display and do not represent actual roadside locations of route signs.

Jim Mossman has also created a set of ArcGIS Desktop.style files and ArcInfo Workstation markersets. Follow the directions in the download to install.

A third related statewide layer, EXITS_PT, represents major highway exit locations. Attributes include the exit number and the highway route number associated with each exit.

The linework in the Major Roads layer was extracted from the MHD Roads layer. Classes 1-5 were selected, routes built on the RT-NUMBER item, and two classes of annotation (MAJOR and MAJOR2) were copied from the MHD Roads layer. MassGIS staff used workstation Arc/Info to do the processing. Please note that the reselection of classes 1-5 left some discontinuous arcs, resulting in dangles. Some such arcs were connected for continuity, but some dangles remain.

Please refer to the digital metadata files for a complete listing of item descriptions and attributes.

The MAJRDMHD.AAT (arc attribute table) contains the following items:

Item Name		Defnition		Description
CLASS		1-1-I		Designates a road based on functional classification and access; used for plotting. Classes are:  1 - Limited Access Highway  2 - Multi-lane Highway, not limited access  3 - Other numbered route  4 - Major road, collector  5 - Ramp, connector The CLASS item was coded using information in the MRD.INV table as follows:  1 = ACC_CON = 1 AND AUTO-RT-NUMBER NC '    '  2 = (ACC_CON = 0 OR ACC_CON = 2) AND (DIV-L-NUM-TR-LA > 1 AND AUTO-RT-NUMBER NC '   ')  3 = (ACC_CON NE 1) AND (DIV-L-NUM-TR-LA LE 1 AND AUTO-RT-NUMBER NC '    ') AND (FUNC-CLASS > 0)  4 = (FUNC-CLASS > 0 AND FUNC-CLASS < 6) AND (AUTO-RT-NUMBER CN '    ') Class 5 comprises some class 5 and 7 arcs from the MHD Roads layer which were selected as follows: (CLASS = 7 AND STREET_NAME CN 'RAMP-RT' AND STREET_NAME CN 'TO RT') OR (STREET_NAME CN 'ROUTE' AND STREET_NAME CN 'CONNECTOR' AND CLASS GT 4). This class includes ramps and connectors (e.g., cloverleafs) that allow access from one major road to another.
ADMIN_TYPE		1-1-I		Based on AUTO-RT-SIGN from MRD.INV file. Types are:  1 - Interstate  2 - U.S. Federal  3 - State  4 - Major Road / Collector Roads with more than one sign type are preferenced in the above order.
RT-NUMBER		4-4-C		Route number of the road type listed in ADMIN_TYPE (where ADMIN_TYPE is 1-3)
ALTRTNUM1 ALTRTNUM2 ALTRTNUM3 ALTRTNUM4		4-4-C		Alternate Route numbers. Type is either U.S. or State route for ALTRTNUM1, as indicated in the ALTRT1TYPE item. All other alternate routes are State routes. No road in the state has more than four alternate routes.
ALTRT1TYPE		1-1-I		Administrative Type for ALTRTNUM1 (U.S. Route = 2, State Route = 3)
STREET_NAME		40-40-C		Street name from the MRD.STREETS file (see details of this INFO table below)
RT-ID		4-4-I		Markerset symbol number for RT-NUMBER, used for plotting in ArcPlot.
ART-ID		4-4-I		Markerset symbol number for ALTRTNUM1, used for plotting in ArcPlot.
CSN		8-8-C		Uniquely identifies any roadway segment within the entire state. This item is the link to the road inventory file (mrd.inv) (in the QUAD library's database directory in using data in Librarian).

The MHDRDPTS.PAT (point attribute table) contains the following items:

RT-NUMBER		4-4-C		Route Number
ALT-RT-NUMBER		4-4-C		Alternate Route Number
RT-ID		4-4-I		Markerset symbol number for RT-NUMBER, used for plotting in ArcPlot
ART-ID		4-4-I		Markerset symbol number for ALT-RT-NUMBER, used for plotting in ArcPlot
MARKER		3-3-I		Code for scale dependency when plotting markers
FUNC-CLASS		1-1-I		Functional class for road of RT-NUMBER from MHD

The EXITS.PAT (point attribute table) contains the following items:

INTMARK-ID		4-5-B		Exit number
ROUTE		4-4-C		Route Number associated with exit location

 MAINTENANCE

MassGIS produces this layer from the Quad-tiled MHD Roads layer. It is updated upon receiving a new dataset from MHD, at least once a year.

Last Updated 9/24/2004
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