Route and Transportation Surveys Flashcards

Using the arc definition, what is the degree of curve for a simple circular curve with a radius of 573 feet?

Answer: 10°

Using the arc definition, D = 5729.578 / R = 5729.578 / 573 ≈ 10°.

The tangent length (T) of a simple horizontal curve with radius R and intersection angle Δ is calculated as:

Answer: T = R × tan(Δ/2)

The tangent length is T = R × tan(Δ/2), derived from the right triangle formed by the radius, tangent, and line to the PI.

In route surveying, what does the abbreviation 'PI' stand for?

Answer: Point of Intersection

PI stands for Point of Intersection, which is where the two tangents of a horizontal curve meet.

A compound curve in route surveying consists of:

Answer: Two or more circular arcs with different radii curving in the same direction

A compound curve uses two or more circular arcs of different radii that both curve in the same direction, sharing a common tangent at the point of compound curvature (PCC).

The external distance (E) of a simple horizontal curve is the distance from:

Answer: The PI to the midpoint of the curve

The external distance E is measured from the PI to the midpoint of the curve (the point on the arc closest to the PI), calculated as E = R(sec(Δ/2) − 1).

The arc length (L) of a simple horizontal curve with radius R and central angle Δ expressed in radians is:

Answer: L = R × Δ

Arc length equals the radius multiplied by the central angle in radians: L = R × Δ.

In the chord definition of degree of curve, D is the central angle subtended by a chord of what length?

Answer: 100 feet

The chord definition defines D as the central angle subtended by a 100-foot chord, commonly used in railroad surveying in the US.