Which statement describes a Single Line (bi-directional) operation?

Which statement describes a Single Line (bi-directional) operation?

• A. Trains can run up and down on a single line
• B. Three or more lines in operation
• C. Two separate parallel lines for up and down
• D. A single-direction line

Answer: (A)

Moving in both directions on the same track is what Single Line bi-directional operation means. This setup relies on signaling and control so trains traveling toward each other don’t meet on the same section, using passing places to allow them to pass when needed. The statement trains can run up and down on a single line describes this situation exactly. Other scenarios describe multiple tracks or a line that only allows one direction, which do not fit the idea of one line used for traffic in both directions.

Moving in both directions on the same track is what Single Line bi-directional operation means. This setup relies on signaling and control so trains traveling toward each other don’t meet on the same section, using passing places to allow them to pass when needed. The statement trains can run up and down on a single line describes this situation exactly. Other scenarios describe multiple tracks or a line that only allows one direction, which do not fit the idea of one line used for traffic in both directions.