A coefficient that is a function of the design
speed. Obtained from the AASHTO Design guide. Usually
in the range 0f 0.1 to 0.3.

Grade

Grade is the rise or fall of the roadway profile
per 100 units in length. Usually expressed as a %

gravitational
constant, g

g = 9.81 m/s^{2} or 32.2 ft/s^{2}

Super
elevation, e%

The cross slope to a road that is used to counteract
the centripetal forces developed as a vehicle goes around a
curve. Maximum value is approximately 10%

Stopping
Sight Distance

The distance required for a vehicle to observe,
react and brake the vehicle to a stop. Calculated in two parts:
the perception reaction distance and the braking distance

Velocity,
V

Speed of the design vehicle

Vertical
Curve

A regular curve that has a quadratic mathematical
form. For vertical curves the general equation is

A is the grade difference

L is the length of parabolic curve

X= distance from beginning of the
curve to the point of interest