Along horizontal and vertical curve alignments, alignment stakes are placed how often?

• A. Every mile
• B. Every quarter or half station
• C. Only at the curve's ends
• D. Every two stations

Answer: (B)

Placing stakes at short, regular intervals along a curve gives enough reference points to accurately transfer the design onto the ground. Since a station is 100 feet, a quarter station is 25 feet and a half station is 50 feet. Using these increments provides a practical balance between precision and labor: you have plenty of points to control the curve’s geometry, including the centerline through the curve, the tangents, and any transitions, without creating an excessive number of stakes. This density helps prevent cumulative errors as you lay out the line and check how the curve progresses from straight to curved, and it also aids in marking the vertical alignment changes along the profile. Stakes only at the ends or spaced every two stations would leave gaps too large to maintain the intended curvature accurately, especially on longer or sharper curves.