Super Elevation Calculator

Design Parameters

Design Standard

Design Speed

Curve Radius

Side Friction Factor (f)

Default values based on selected standard

Road Parameters

Road Width (per lane)

meters

Number of Lanes

Divided Highway

Max Superelevation Rate

Typically 7-10% (IRC: 7%, AASHTO: 10%)

Results

Super Elevation Rate (e)

0.00%

Ratio: 1:0

Banking Angle (θ)

0.00°

Transition Length

0.00 m

Outer Edge Elevation

0.00 m

For 3.5m wide lane

Adverse Camber Check

Not Required

Speed vs Radius Analysis

Road Cross-Section Preview

Visual representation of superelevated road section (exaggerated for clarity)

Reference Tables

IRC Recommended Values

Speed (km/h)	Max 'f'	Max 'e' (%)
20	0.21	7.0
30	0.18	7.0
40	0.16	7.0
50	0.15	7.0
60	0.15	7.0
70	0.14	7.0
80	0.14	7.0
100	0.13	7.0
120	0.12	7.0

AASHTO Recommended Values

Speed (mph)	Max 'f'	Max 'e' (%)
15	0.21	10.0
20	0.19	10.0
25	0.18	10.0
30	0.17	10.0
35	0.16	10.0
40	0.15	10.0
45	0.14	10.0
50	0.14	10.0
55	0.13	10.0
60	0.12	10.0
65	0.11	10.0
70	0.10	10.0
75	0.09	10.0
80	0.08	10.0

About Superelevation

What is Superelevation?

Superelevation is the banking of a roadway along a horizontal curve so that the outer edge of the road is higher than the inner edge. This helps counteract the centrifugal force experienced by vehicles navigating the curve, improving safety and comfort.

Why is it Important?

Proper superelevation design:

Reduces the risk of skidding or overturning
Improves vehicle stability on curves
Enhances driver comfort
Increases safety, especially in wet conditions
Allows for higher design speeds on curves

Design Considerations

The superelevation rate (e) is calculated using the formula:

e + f = V² / (127R)

Where:

e = superelevation rate (decimal)
f = side friction factor
V = design speed (km/h)
R = radius of curve (m)

Transition Curves

Transition curves are used to gradually introduce superelevation from normal crown to full superelevation. The length depends on the design speed and rate of rotation.