Vertical Curve Calculator
Calculate vertical curve parameters for road design and construction projects. Enter your values below to compute the curve elevation at any point.
Professional Engineers: Get precise vertical curve calculations in seconds. Our tool helps you avoid costly design errors and ensures compliance with engineering standards.
Need Professional Engineering Services?
Our team of licensed engineers can help with your road design and construction projects.
Call now for a free consultation and quote tailored to your project needs!
Frequently Asked Questions
What is a vertical curve in road design?
A vertical curve is a transition between two different grades (slopes) in a roadway. It provides a smooth change in elevation for vehicles, improving safety and comfort. There are two types: crest curves (when transitioning to a lower grade) and sag curves (when transitioning to a higher grade).
How do you calculate vertical curve elevation?
The elevation at any point on a vertical curve can be calculated using the parabolic equation: E = EPVI + G1x + (G2-G1)x²/2L, where E is elevation, EPVI is PVI elevation, G1 and G2 are grades, x is distance from PVC, and L is curve length.
What is the K value in vertical curves?
The K value represents the horizontal distance required to achieve a 1% change in slope. It’s calculated as K = L/|G2-G1|. K values are used to determine minimum curve lengths based on design speed to ensure adequate sight distance.
What are typical vertical curve lengths?
Typical vertical curve lengths vary based on design speed and grade change. For highways, curves might range from 100-500 feet for low-speed roads to over 1000 feet for high-speed freeways. Minimum lengths are specified by design standards like AASHTO.