DA 12-121
Attachment B:  Road Categories, Descriptions, and Total Miles 
in Preliminary List of Potentially Eligible Census Blocks
MTFCC Feature Class Feature Class Description Total Miles
S1100 Primary Road Primary roads are generally divided, limited-access highways 
within the interstate highway system or under state 
management, and are distinguished by the presence of 
interchanges. These highways are accessible by ramps and may 
include some toll highways.
474
S1200 Secondary Road Secondary roads are main arteries, usually in the U.S. Highway, 
State Highway or County Highway system. These roads have 
one or more lanes of traffic in each direction, may or may not 
be divided, and usually have at-grade intersections with many 
other roads and driveways. They often have both a local name 
and a route number.
37,164
S1400 Local 
Neighborhood 
Road, Rural Road, 
City Street
Generally a paved non-arterial street, road, or byway that 
usually has a single lane of traffic in each direction. Roads in 
this feature class may be privately or publicly maintained. 
Scenic park roads would be included in this feature class, as 
would (depending on the region of the country) some unpaved 
roads.
665,314
S1500 Vehicular Trail 
(4WD)
An unpaved dirt trail where a four-wheel drive vehicle is 
required. These vehicular trails are found almost exclusively in 
very rural areas. Minor, unpaved roads usable by ordinary cars 
and trucks belong in the S1400 category.
81,640
S1630 Ramp A road that allows controlled access from adjacent roads onto a 
limited access highway, often in the form of a cloverleaf 
interchange. These roads are unaddressable.
115
S1640 Service Drive 
usually along a 
limited access 
highway
A road, usually paralleling a limited access highway, that 
provides access to structures along the highway. These roads 
can be named and may intersect with other roads.
12,609
S1730 Alley A service road that does not generally have associated 
addressed structures and is usually unnamed. It is located at the 
rear of buildings and properties and is used for deliveries.
211
S1740 Private Road for 
service vehicles 
(logging, oil fields, 
ranches, etc.)
A road within private property that is privately maintained for 
service, extractive, or other purposes. These roads are often 
unnamed.
38,255
S1750 Internal U.S. 
Census Bureau 
use.
Internal U.S. Census Bureau use. 1,497
837,278
Source:  Appendix F – MAF/TIGER Feature Class Code (MTFCC) Definitions, pages F-186 and F-187, at 
http://www.census.gov/geo/www/tiger/tgrshp2010/documentation.html (last visited Feb. 2, 2012), and FCC 
analysis.