Datasets created for the Border Environmental Health Initiative (BEHI) follow watershed boundaries as defined by Woodward and Durall (1996). As part of the U.S.-Mexico Border Field Coordinating Committee Issues Team, Woodward and Durall used surface-water drainage basins as the primary basis for defining and delineating the extent of the border area from a shared-water resources perspective. In order to provide integrated datasets in the border region, local and regional BEHI datasets have been clipped to this boundary.
This major road feature class is an aggregate of US (1:2 million scale) and Mexican (1:250,000-scale) road data, in which new common classes have been assigned to all road segments. The classes for the major road feature-class are: primary route, secondary route, and tertiary route. This classification scheme ranks roads not solely on number of lanes, surface type, or condition, but also attempts to use relative importance of a given road.
Sorted INEGI 1:250K roads layer to make categories to fit with US roads, using this criteria:
For Carretera (Highway) 1. 4 or more lanes = A10 2. Federal = A10 3. 2 lanes = A20 4. State = A20 5. 1 lane or dirt road = A30
For Calle (Street) 1. All = A20 2. All Calle in this case are highways that run through cities.
Decided not to use the Camino (Way) roads for the binational layer.
A10 = Primary Route (4 or more lanes and/or Federal) A20 = Secondary Route (2 lanes and/or State) A30 = Tertiary Route (1 lane or unimproved main road not State or Federal)