Superelevation Calculation Excel Sheet -

= MIN( F2, D2 ) (check):

= IF( F2 <= D2, "OK", "e_max insufficient – increase radius or reduce speed" ) (minimum radius for given speed and e_max):

= (B2^2) / (127 * C2) - E2 (adopted e):

| Speed (km/h) | f_max | |--------------|-------| | 30 | 0.17 | | 40 | 0.17 | | 50 | 0.16 | | 60 | 0.15 | | 70 | 0.14 | | 80 | 0.14 | | 90 | 0.13 | | 100 | 0.12 | | 110 | 0.11 | | 120 | 0.09 |

=VLOOKUP(B2, $J$2:$K$11, 2, TRUE) (required e): superelevation calculation excel sheet

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.

| A | B | C | D | E | F | G | H | I | |---|---|---|---|---|---|---|---|---| | Curve ID | Design Speed (km/h) | Radius (m) | e_max (max superelevation) | f (from table) | Required e (calc) | Adopted e | Check (e ≤ e_max) | R_min (m) | In a separate sheet (or same sheet, columns J–L), create a lookup table for side friction factor (f) vs design speed (AASHTO Green Book 2018): = MIN( F2, D2 ) (check): = IF(

= (B2^2) / (127 * (D2 + E2)) (if e is limited):

[ e + f = \fracV^2g \cdot R ]

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.