Road maps (navigation)

Navigation maps are intended for assessment of roads traffic capacity, length of road sections between settlements, presence of gas stations, service stations and other facilities.

They are made by digital topographic maps, remote sensing data, road atlases. Basis of navigation maps is the graph of roads.

Graph of roads - is a digital vector map consisting of topologically connected arcs and knots, location and properties of which with a given accuracy and completeness transfer the routes and organization of ground traffic.

Graph of roads is created according to the Requirements for navigational maps, including the description of the classifiers, rules of digital description, data formats, editorial and technical instructions and other documents.

Elements of the road graph are intended for use in the tasks on the automated laying the routes between any specified points on the graph.

The graph of roads is created by selected objects of the road network and is the user map with arcs and nodes. At the stage of construction into semantic characteristics of the arcs and nodes there are recorded the information about network connectivity and attributes for solving the search tasks. You can create arcs of two types - with two-way and one-way traffic.

Roads graph editing tools are intended for refinement of the graph in places of multilevel junctions and formations of interdictions of turns.

The user has possibility manually to remove, to add network nodes, to replace an arc with two-way traffic onto arc with one-way traffic, to do paralleling of roads, to create arcs and turns, to form at crossroads the interdictions of turns.

Search of the minimum path between points (settlements) is carried out taking into account any characteristics written down into network arcs (type of roads, speed of movement, number of carriageways). The shortest route can be found or by the minimal length of the path or by the minimum time of a route passage. At a finding of the minimal path there is a possibility of elimination of some arcs, for example emergency sites, from the search. Search results are displayed on the map in the form of object-route.