2 Vertical curves A crest vertical curve is to be designed to join a 2.5% upgrade with a 3% downgrade at a section of a two-lane highway. The design speed of the highway is 55 mi/h. A. Determine the minimum length of the curve for safe stopping sight distance (demonstrate that the used formula for L satisfies the appropriate relation between L and SSD). Use design values for the PIEV time and vehicle deceleration rate once the brakes are hit. B. If the elevation of PVI point is 400 ft above the sea-level, calculate the elevation of PVC point above the sea level (Y). C. Write down the parabolic equation of the vertical curve denoting its height (Y) as a function of horizontal distance from the PVC point (x).

2 Vertical curves A crest vertical curve is to be designed to join a 2.5% upgrade with a 3% downgrade at a section of a two-lane highway. The design speed of the highway is 55 mi/h. A. Determine the minimum length of the curve for safe stopping sight distance (demonstrate that the used formula for L satisfies the appropriate relation between L and SSD). Use design values for the PIEV time and vehicle deceleration rate once the brakes are hit. B. If the elevation of PVI point is 400 ft above the sea-level, calculate the elevation of PVC point above the sea level (Y). C. Write down the parabolic equation of the vertical curve denoting its height (Y) as a function of horizontal distance from the PVC point (x).

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter15: Geometric Design Of Highway Facilities

Section: Chapter Questions

Problem 19P

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