Built-up areas representation on topographic map
Content rules of topographic maps
Digital topographic map and its requirements
Growth representation on topographic maps
Hydrography representation on topographic map
Object representation on topographic map
Principles of digital topographic map classification
Programs for working with raster maps
Road representation on topographic map
Soil representation on topographic map
The notion of a map
The process of digital topographic maps creation
Road representation on topographic map
Highways and dirt roads
Motor roads can be with pavement (highways) and without pavement (improved dirt roads). A big impact on movement of the equipment has road width, type of pavement, size of longitudinal slope and turning radius, presence and character of road buildings.
Type of pavement determines road durability and service life. Main types of pavement are asphalt, concrete, stone, gravel, macadam and cobblestone. Dirt, field and forest roads are useable for equipment movement only in summer. Its passability depends on solid character and level of moisture. If there is heavy traffic the road will soon destroy.
Steepness of road ascents and descents is called slope. Amount of slope is expressed in per cents and by the following formula:
i = (h / L) * 100
where h - height of ascents and descents, L - length of ascents and descents
Slope equal to 1% denotes 1 meter ascent or descent in every 100 meter of the road. The biggest longitudinal slopes do not go beyond 6-7% in flat area and 9-10% in mountainous area. Amount of turning radius influences on movement of military and other technics. The smallest turning radius for road trains and prime movers is 20 meters. As a rule turning more than 350 meters vehicles pass without retarding the speed. A big number of steep turnings to a great extend limit visibility thus lower the speed significantly.
Presence and character of road buildings (bridges, tunnels, embankments, etc) also influences on military technics movement. They, as a rule, are usually destroyed with the purpose of forming obstacles for enemy troops.
Motor and dirt roads representation
Motor and dirt roads while mapping are usually divided according to its technical perfection and passability into classes. Representation of improved dirt roads on topographic maps is accompanied by sign of carriageway width and pavement type - in addition to solid. Width of dirt (country) road is signed in places, where driveway is possible only along the road, for example, in forest, marsh, etc. In little-inhabited regions and regions which are difficult of access road representation may be accompanied by sign, characterizing road passability or locality out of road for various means of transport, for example: "Transport movement is possible from July till September at the speed 40 km per hour". Representations of roads, which are building now, are also always signed. Road junctions, lay-outs for transport, road numbers, light roadside buildings, exits are also shown on topographic map. Dirty (country) roads on maps with scale 1:25000 are all depicted, on topographic maps with scale 1:50000 and smaller selectively. Improved dirty roads on topographic maps with scale 1:25000-1:50000 are also always depicted, but on maps with scale 1:100000 and smaller selectively.
Highways and improved motor roads representation
Highways, improved motor roads, are always depicted on map. On lines of conventional signs of macadam roads and highways by means of special conventional signs areas with little turning radius (less than 25 meters) and areas with large slopes (8% and more) are marked.
Representation of main roads and highways on topographic maps is accompanied by sign of its characteristics: width of carriageway (for highways width of one lane and number of lanes), width of road bed (for main roads), and type of pavement (asphalt, cobble, gravel, concrete, stone, etc.). Boundaries of pavement type changing are also depicted.
Railroads while mapping are divided: according to the gauge width into broad gauge (1435 mm and more, in Russia 1524 mm) and narrow gauge (less than 1435 mm); according to the number of tracks into single-track, double-track, three-track according to the type of traction into electrified and others ( diesel or steam traction); according to the condition into working, building, non-assembled.
Monorail railroads, underground lines, passing on the surface, also tram lines, tramways, cable cars, and planes are depicted on topographic maps. Building and narrow gauge railroads are represented without division according to the number of tracks and type of traction. Permanent way of non-assembled railroads is depicted by means of special conventional sign. Areas of railroad with slope more than 20% are marked out by means of stroked conventional character in the form of an angle. Cargo-handling areas with width more than 1,5 mm in the map scale are showed according to its real extension. All metro stations are, as a rule, showed on topo maps with scale 1:25000 and 1:50000.
Railway stations, crossing, platforms which are not coincide with map scale are represented without reference to its class by means of one conventional sign. When depiction of railway station coincides with map scale, depot, railway stations, station tracks, turning circles, foot-bridges across station racks, and other objects are represented on topo map. Depot and railway station are represented by means of special conventional sign. Proper names of stations, crossings, platforms, situated outside built-up area, are always depicted. But when they are situated in built-up areas or nearby their names are not depicted, but the names of built-up areas (except cities) are represented with excretion by means of thin line. Names of railway stations, situated out of built-up areas, are depicted.
Bridges and overbridges, expressed in map scale, with width more than 30, 60 and 120 meters are represented respectively on topographic maps with scale 1:25000, 1:50000, 1:100000 according to its real size and are divided according to the building material into wooden, metallic, stone, concrete and according to the construction into plain, two tier, elevating, pontoon and drawbridge. The rest of bridges are shown on topo maps without reference to the building material or construction by means of conventional sign with division into bridges with length 3 meter and more and bridges with length less than 3 meters (bridges across insignificant barriers, pipe for water flow).
Railway bridges representation with length 100 meters and more is accompanied by sign of building material, the altitude framework bottom above water-level (in mean water) or above surface and the length in meters. Representation of bridges with length less than 100 meters is accompanied only by sign of building material. Representation of bridges on main and dirt roads are accompanied by sign only if bridge is more than 3 meters. Herewith building material, width and length in meters, carrying capacity is pointed in tons.
Tunnels in railroads and motor roads are all depicted on topographic maps. Its representation is accompanied with pointing height, width and length of tunnels.
Road embankments and cuttings are represented on topographic maps with scale 1:25000 and 1:50000 if its height (depth) is 1 meter or more, and on topographic maps with scale 1:100000 and 1:200000 if its height (depth) is respectively 2 meters or 3 meters and more. Embankments and cuttings representation is accompanied by sign of its relative height (depth) in meters.
Distance marks (posts and stones) on motor and dirt roads are represented on maps in areas where there is a lack of reference points. At the same time representation of distance marks in some distinct region is accompanied by sign of kilometer number, indicated on distance mark.