Figure 1-8 Bridge Symbols
All multiple track railroads, most single-track railroads, and some abandoned railroads are
portrayed on ONC and TPC charts. Typically, railroads are sufficiently sparse and can be readily
identified and distinguished from each other. Railroads may make smaller fix points (small
towns, intersections) more identifiable. Railroads are not always easy to see from low altitudes,
even though they are portrayed boldly on the chart.
1. As a rule, railroads are easier to detect in hilly or mountainous
terrain than in flat populated areas. Since a locomotive must
operate on gentle grades and turns, the track bed in mountainous
regions are normally characterized by numerous cuts, fills, trestles,
and tunnels. Thus, the features associated with the track bed lend
visual significance to the railroad. Railroad yards are excellent
radar checkpoints, and generally shown if they exceed 2000 feet in
length and five tracks in width. Railroad stations have distinctive
buildings, and are generally shown in areas of sparse culture.
CHART LEGEND REVIEW