1. SIMPLE.

The simple curve is an arc of a circle. The radius of the circle determines the sharpness or flatness
of the curve.

2. COMPOUND. Frequently, the terrain will require the use of the compound curve. This
curve normally consists of two simple curves joined together and curving in the same direction

.3. REVERSE. A reverse curve consists of two simple curves joined together, but curving
in opposite direction. For safety reasons, the use of this curves should be avoided when
possible.

4. SPIRAL. The spiral is a curve that has a varying radius. It is used on railroads and most
modem highways. Its purpose is to provide a transition from the

¢ REVERSE ء٤۶‎ 0 ടല curve

2.a. ( Explain any 3 methods with fig and equations.5 mark for each. Fig+equations=
3+2,)(5x3=15)

The following are some of the linear methods used for setting out simple circular curves:
(i) Offsets from long chord
(ii) Successive bisection of chord

(111) Offsets from the tangents—perpendicular or radial (iv) Offsets from the chords produced.