Superelevation Calculation Excel Sheet < ORIGINAL × 2024 >

| 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 |

| 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):

Manually calculating superelevation for multiple curves is time‑prone to errors. An automates the process based on the governing design standards (e.g., AASHTO Green Book, IRC, AS 5100). This article explains the theory, the step‑by‑step calculation procedure, and how to build a reusable Excel sheet. Key Parameters for Superelevation Calculation | Parameter | Symbol | Typical unit | Description | |-----------|--------|--------------|-------------| | Design speed | V | km/h or mph | Regulates the curve’s radius and superelevation | | Curve radius | R | m or ft | Centreline radius of the horizontal curve | | Side friction factor | f | dimensionless | Coefficient of lateral friction between tyre and pavement | | Superelevation rate | e | m/m or % | Transverse slope (e.g., 0.07 = 7%) | | Acceleration due to gravity | g | 9.81 m/s² | Constant | Fundamental Equation For a vehicle on a curved path, the equilibrium of forces gives the basic superelevation formula:

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

= MIN( F2, D2 ) (check):

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

=VLOOKUP(B2, $J$2:$K$11, 2, TRUE) (required e): | Speed (km/h) | f_max | |--------------|-------| | 30 | 0

[ e_required = \fracV^2127 \cdot R - f ]

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.

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

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.

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

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. Key Parameters for Superelevation Calculation | Parameter |