Structure of the street graph of Warsaw, as used in simulations.
Part of the data comes from the Open Street Map.
The first part of the file contains information about nodes of the graph -
each node has an identifier and geographic coordinates:
The second part is a list of edges: start and end nodes, length in kilometers,
number of lanes, and average maximum velocity (think of it as a speed limit on a given street):
Road segments with average maximum velocity equal 60 km/h are called minor.
The other ones, with higher velocity, are called major.