Military

APPENDIX H

THE ROUTE CLASSIFICATION SYSTEM

This appendix implements STANAGs 2253 and 2174

The military route classification system helps in planning and executing battlefield movements. The Highway Traffic Division classifies routes based on how much control is to be exerted on the route. From most to least control, routes are classified as prohibited, reserved, dispatch, supervised, and open.

The degree of control on a route is usually set by the and PM. However, if a route is reserved for a unit, then the commander of that unit decides how much and what kind of control is needed.

Route classifications are developed by military engineers. They use (STANAG 2174) a route classification formula. The formula is made up of a series of numbers and letters that express, in a standard sequence, the route width, route type, lowest military load classifications, overhead clearance, obstructions to traffic flow, and special conditions on a given route. They base their findings on information extracted from route recon reports.

MP make hasty route recons to check route conditions and report changes affecting the route's classification. Routes are classified under favorable light and weather conditions. When movement will be under conditions other than favorable, such as blackout movement, recon instructions must include the ways by which a movement can be completed.

ROUTE CLASSIFICATION COMPONENTS

The report of a hasty route recon usually consists of a map overlay, supplemented by additional reports about various aspects of the terrain. A map overlay is a drawing of a route and its characteristics. The overlay should be prepared on transparent paper when possible.

The route recon overlay is accurate, clear, and concise. Standard topographic symbols, military symbols, and overlay symbols are used to ensure that route recon reports are universally understood. The route classification is used on the route recon overlay.

ROUTE WIDTHS

The width of a route is determined by its narrowest portion, whether that be roadway, bridge, tunnel, or other constrictions, and is expressed in meters or feet (STANAG 2253). The width of the traveled way sets the number of lanes of a given route. The number of lanes determines traffic flow. One lane can accommodate vehicular traffic in one direction only, allowing no over taking in the same direction or passing in the oncoming direction.

A route is single flow when it allows a column of vehicles to proceed and, in addition, lets individual oncoming or overtaking vehicles pass at predetermined points. The width of a single-flow route should be equal to at least 1 1/2 lanes.

A route is double flow when it allows two columns of vehicles to proceed abreast at the same time, whether or not they are moving in the same direction.

In a hasty route recon, instructions indicate whether the anticipated traffic is to be single or double flow and whether the route is for the use of wheeled vehicles or tracked vehicles. In the absence of instructions, routes are reconnoitered and reported based on the minimum traveled way width for double-flow, tracked vehicles.

ROUTE TYPES

For the purpose of classification, routes are designated by their ability to withstand the effects of weather. Route type is determined by the worst section of the route. There are three types of routes (STANAG 2174):

  • Type X is an ail-weather route that, with reasonable maintenance, is passable throughout the year to maximum capacity traffic. The roads that form this type of route normally have waterproof surfaces and are only slightly affected by precipitation or temperature changes. At no time is the route closed to traffic by weather conditions other than temporary snow or flood blockage.
  • Type Y is a limited all-weather route that, with reasonable maintenance, can be kept open in all weather but is sometimes open to less than maximum capacity traffic. The roads that form this type of route usually do not have waterproof surfaces and are considerably affected by precipitation or temperature changes. The route may be closed for short periods of up to one day at a time by adverse weather conditions during which heavy use of the road would probably lead to complete collapse.
  • Type Z is a fair-weather route that quickly becomes impassable in adverse weather and cannot be kept open by maintenance short of major construction. This category of route is so seriously affected by weather that traffic may be brought to a halt for long periods.

MILITARY LOAD CLASSIFICATIONS

The military classifies and assigns a load-carrying capacity, shown in whole numbers, to vehicles, bridges, roads, and routes. Vehicles are classified by weight, type, and effect on routes. Bridges, roads, and routes are classified by physical characteristics, type and flow of traffic, effects of weather, and other special conditions.

Usually, the lowest bridge classification number (regardless of vehicle type or conditions of traffic flow) sets the load classification of a route. If no bridge is located on the route, the worst section of road governs the route's classification. Vehicles having higher load classifications than a particular route are sometimes able to use that route if a recon overlay or a special recon shows that a change in traffic control, such as making a bridge a single-flow crossing, would permit use of the route by heavier traffic.

Whenever possible, the basic military road network is composed of average routes and includes a number of heavy traffic routes and a few very heavy traffic routes. The class of a military road maneuver network is fixed by the minimum route classification of the network. Individual routes are grouped and identified in broad categories:

  • Average traffic routes
  • Heavy traffic routes
  • Very heavy traffic routes

- Class 50

- Class 80

- Class 120

OVERHEAD CLEARANCE

Overhead clearance is the vertical distance between the road surface and any obstruction over it that denies use of the route/road to all vehicles or loads that exceed this height. If clearance is unlimited, symbolize it by using in the route classification formula.

ROUTE OBSTRUCTIONS

Route obstructions are factors that restrict the type, amount, or speed of traffic flow. Route obstructions are indicated in the route classification formula by the abbreviation (OB). If an obstruction is shown in the route classification formula, the route recon overlay will show the exact nature of the obstruction. Recon overlay symbols are used to describe the nature of each obstruction on the route recon overlay. Certain obstructions must be reported:

  • Overhead obstructions, like bridges, tunnels, under passes, overhead wires, and overhanging buildings, with overhead clearance of less than 4.3-meters (14-feet).
  • Reduction in traveled way widths that are below standard minimums prescribed for the type of traffic flow, such as bridges, tunnels, craters, lanes through mined areas, and projecting buildings or rubble.
  • Gradients (slopes) of 7 percent or greater.
  • Curves with a radius of 25 meters (82.5 feet) and less (STANAG 2253).
  • Ferries.
  • Fords.

SPECIAL CONDITIONS

Some "obstructions" are temporary or special conditions. Snow is not usually classified as an obstruction to traffic as vehicular movement depends on the depth of the snow and/or the presence of snow removal equipment. But, where snow blockage is regular, recurrent, and serious, the route classification formula is followed by (T).

Flooding is not usually a factor in classifying routes unless flooding is regular, recurrent, and serious. Then the route classification formula is followed by (W).

ROUTE RECON SYMBOLS



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