Extend the sheet to calculate superelevation runoff lengths and pavement cross‑section elevations at stations along the curve. With Excel’s built‑in functions, you can also generate banking diagrams automatically.
= MIN( F2, D2 ) (check):
Since 6.16% ≤ e_max (7%), . Check passes. Minimum radius for 80 km/h & e_max 7%: R_min = 6400 / (127 × (0.07+0.14)) = 6400 / (127×0.21) = 6400 / 26.67 = 240 m → R=250 m is adequate. Advanced Features to Add | Feature | Implementation | |---------|----------------| | Transition length | L = (e × normal crown width) / superelevation runoff slope | | Runoff length | Based on relative gradient (AASHTO Table 3‑21) | | Tangent runout | L = (normal crown % × width) / relative gradient | | Curve types | Drop‑down list (simple, spiral, compound) | | Graphical output | Plot e vs R for a given speed (parabolic limit curve) | | Unit conversion | Automatically handle m → ft, km/h → mph | Complete Excel Sheet Layout (Example Data) | Curve ID | Speed | Radius | e_max | f | Req e | Adopted e | Check | R_min | |----------|-------|--------|-------|----|-------|-----------|-------|-------| | C1 | 80 | 250 | 0.07 | 0.14 | 6.16% | 6.16% | OK | 240 | | C2 | 100 | 400 | 0.08 | 0.12 | 7.68% | 7.68% | OK | 315 | | C3 | 60 | 120 | 0.06 | 0.15 | 8.66% | 6.00% | e_max insufficient | 137 | In C3, required e (8.66%) > e_max (6%) → adopted e = 6%, but the actual friction will be higher than allowed – warning triggered. Conclusion A well‑designed Excel sheet for superelevation calculation eliminates repetitive manual work and ensures compliance with design standards. By embedding the equilibrium equation, friction lookup tables, and safety checks, you create a robust tool for highway designers. superelevation calculation excel sheet
Introduction Superelevation (also known as cant or banking) is the transverse slope provided to a road or railway curve to counteract the effect of centrifugal force on vehicles. Properly designed superelevation ensures safety, comfort, and stability for vehicles negotiating a horizontal curve. Extend the sheet to calculate superelevation runoff lengths
= IF( F2 <= D2, "OK", "e_max insufficient – increase radius or reduce speed" ) (minimum radius for given speed and e_max): Check passes