GeoSpatial Applications

California Geo-spatial Organizations

U.S. Census Bureau - Tiger 2k

The following transportation layers are derived from the US Census Bureau Tiger 2K (June 7, 2002 Version) information. All the layers are statewide and are arranged by their major Census Feature Class Code (CFCC). All data layers are reprojected into the Teale Albers NAD 83 projection, and only a small subset of the attribution is included. Zip Code, and address information is NOT included. CaSIL has divided these transportation layers to help users choose the appropriate level of detail for their project. Please note the size of the datsets, as shown below. In particular note that the local_roads layer is about 40 times the size of the other layers. Do not download it unless you really need it. Users requiring further TIGER information, are encouraged to use the native TIGER files (also on CaSIL) or directly from the Census Bureau. Primary Highway With Limited Access Interstate highways and some toll highways are in this category (A1) and are distinguished by the presence of interchanges. Primary Road Without Limited Access This category (A2) includes nation-ally and regionally important highways that do not have limited access as required by category A1. It consists mainly of US highways, but may include some state highways and county highways that connect cities and larger towns. Secondary and Connecting Road This category (A3) includes mostly state highways, but may include some county highways that connect smaller towns, subdivisions, and neighborhoods. Local, Neighborhood, and Rural Road A road in this category (A4) is used for local traffic and usually has a single lane of traffic in each direction. In an urban area, this is a neighborhood road and street that is not a thorough-fare belonging in categories A2 or A3. In a rural area, this is a short-distance road connecting the smallest towns; the road may or may not have a state or county route number. Vehicular Trail A road in this category (A5) is usable only by four-wheel drive vehicles, is usually a one-lane dirt trail, and is found almost exclu-sively in very rural areas. Road with Special Characteristics This category (A6) includes roads, portions of a road, intersections of a road, or the ends of a road that are parts of the vehicular highway system and have separately identifiable characteristics. Road as Other Thoroughfare A road in this category (A7) is not part of the vehicular highway system. It is used by bicyclists or pedestrians, and is typically inaccessible to mainstream motor traffic except for private-owner and service vehicles. This category includes foot and hiking trails located on park and forest land, as well as stairs or walkways that follow a road right-of-way and have names similar to road names. Railroad Main Line A railroad in this category is the primary track that provides service between destinations. A main line track often carries the name of the owning and operating railroad company. Railroad Spur A railroad in this category is the track that leaves the main track, ending in an industrial park, factory, or warehouse area, or forming a siding along the main track. Railroad Yard A railroad yard track has parallel tracks that form a working area for the railroad company. Train cars and engines are repaired, switched, and dispatched from a yard. Railroad with Special Characteristics A railroad or portions of a rail- road track that are parts of the railroad system and have separately identifiable characteristics.