Obstructions along a road are indicated by the symbol OB at the end of the
formula. Details of the obstructions are shown in Section III on the DA Form 1248 and on
the accompanying overlay. Obstructions to be reported include the following:
Overhead obstructions (such as bridges, tunnels, underpasses, overhead
wires, and overhanging buildings) with an overhead clearance of less than
Reduction in traveled-way widths that are below standard minimums
prescribed for the type of traffic flow (Table 2-1, page 2-5) (such as bridges,
tunnels, craters, lanes through mined areas, and projecting buildings or
Gradients (slopes) of 7 percent or greater.
Curves with a radius of curvature of 25 meters and less (STANAG 2253).
Regular, recurrent, and serious blockage from the effects of snow or flooding are
represented in the road classification formula. The symbol T (for snow blockage) and/or the
symbol W (for flooding) follows the road classification formula. In the case where the
conditions for snow and flooding both exist, a T and a W follows the route classification
Usage and proper sequence of presentation are shown in the following examples
of the road classification formula:
A 5.0/6.2 k. This formula describes a road with no limiting characteristics or
obstructions, a minimum traveled-way width of 5 meters, a combined
traveled-way and shoulder width of 6.2 meters, and a concrete surface.
B g s 4/5 l (OB). This formula describes a road with limiting characteristics
of steep gradients and a rough surface, a minimum traveled-way width of
4 meters, a combined traveled-way and shoulder width of 5 meters, a gravel
or lightly metalled surface, and with an obstruction.
B c (f?) 3.2/4.8 p (4.3 km) (OB) (T). This formula describes a road with
limiting characteristics of sharp curves and unknown foundation, a
minimum traveled-way width of 3.2 meters, a combined traveled-way and
shoulder width of 4.8 meters, a paving brick or stone surface, a route length
of 4.3 kilometers, with an obstruction, and subject to snow blockage.
A 7 + 7/20 k. This formula describes a dual road. Each traveled way is
7-meters wide, and the overall width is 20 meters (including the shoulders).
It has a concrete surface and no limiting factors.