What are the road categories?

The main determining factors in the construction of highways are the traffic intensity of vehicles, speed mode and axle load. Depending on this, the width and the road clothing are projected . Road categories are set according to the combination of the following indicators: actual and reduced traffic intensity, number of lanes, speed, width of strip, width of dividing strip, width of reinforcing edge strip, width of roadbed, maximum longitudinal slope, radius of curve in turn. The main categories of roads in the Russian Federation are I, II, III, IV, V.

I and II categories of highways are assigned to areas with a capital type of coverage, which include different roads that have one to several lanes in each direction. They are designed for speeds of up to 120 km / h (1a - up to 150 km / h), cars with axle loads up to 10 tons can travel, they have wide strips (3.75 m), maximum gradients are limited to 3-4%, radii Turns up to 1200 m.

Wide roadsides and dividing strips (only for the I road category) ensure safety and the necessary throughput. The maintenance of highways of this category includes a wide range of works, in particular, for the I and II categories of roads, the snow is cleaned and the icing is cleaned, as movement is carried out all year round.

For roads of the III category, where there is less traffic, a facilitated improved coating is being arranged. They are allowed to width of strips up to 3.5 m and radiuses of turns - 600 m, their maximum slope can reach 5%. But at the same time vehicles with axle loads of up to 10 tons can drive in sections of Category III. The rated speed mode for them is no more than 100 km / h, the number of lanes to each side is not more than two.

The IV category includes roads with a hard surface, but it may not have improvements (covering from gravel, cobblestones). The width of the lanes on them is no more than 3 m, the maximum of longitudinal slopes can reach 6%, the minimum turning radius is 250 m. The maximum axial load is 6 tons, in winter they should be cleaned, but on the cover one can leave a layer of ice and snow.

If the roads do not have improved coverage, during the spring period they may be restricted by the movement of vehicles of a certain payload capacity. The reason for this lies in the fact that in the spring, because of the great humidification of the roadway, its supporting capacity decreases, and under the influence of a certain axial load deformation of the pavement can occur. If the restriction is not introduced, then in spring along these roads you should move cautiously, taking into account the fact that due to the arising nerves and cracks the friction of the rolling can constantly change, which complicates the control of the machine.

The V category includes roads that do not have a hard surface (laid along the usual soil). To increase the stability of the upper layer, their surface is sometimes treated with special binding additives. In the period of mudslides or during heavy snowfalls, it is allowed to stop traffic. As a rule, they have only one lane, their design speed does not exceed 60 km / h.