The road networks of the 50 US States and the District of Columbia. Graphs are undirected.
Longitude/latitude are given in the format used in the TIGER/Line files (see technical documentation).
Excerpt: Coordinates are decimal degrees expressed in Federal Information Processing Standard (FIPS) notation, where a positive latitude represents the Northern Hemisphere and a negative longitude represents the Western Hemisphere. All coordinates are expressed as a signed integer with six decimal places of precision implied.
road category is adopted directly from the TIGER/Line files (refer to the documentation).
Note that the unit of the average speed is somewhat arbitrarily chosen and does not correspond to any usual unit (like km/h or mph).
The C++ program merge can be used to merge the road networks of two or more states. Compile it with g++ -o merge merge.cpp using, for instance, g++ (GCC) 3.3.5.
Reads file1.tmp and file2.tmp. Writes fileResult.tmp.
Merging more than two files.
Reads a space-separated list of input filenames from standard in. Reads all files on the list. Writes fileResult.tmp.
For each input file filenameX.tmp in TIGER/Line format, the program creates a file filenameX.gr that stores the graph topology and the arc weights, and a file filenameX.co that stores the node coordinates in the plane. If option -T is given in the command line, then arc weights in the resulting graph are travel times, otherwise they are spatial distances in meters between the endpoints.
Notice: road category information is ignored in the translation.