Given Data Initial Road Design: • Design speed: 85 km/h • • Radius of both circular arcs: R = 845 m = 0.44 m/s³ = 250 m • Rate of gain of radial acceleration on all transitions: q Length of straight section between the curves: Lstr Redesigned Road: New design speed: 120 km/h • New radius: R' = 2500 m 3 Horizontal Alignment An existing road with a design speed of 85 km/h passes from one tangent through a right hand circular arc onto a second tangent, and then through a left hand circular arc onto a third tangent which is parallel to the first. The circular arcs are joined to the straights by clothoid transition curves. Radius of both circular arcs Rate of gain of radial acceleration on all transitions Length of straight between the two curves Length of both circular arcs R q Lstr 250 m a) What is the perpendicular distance between the parallel straight sections? b) Using the same tangents and Intersection Points, the arc radii are increased to 2500m and the transition curves upgraded to a design speed of 120 km/h. How long is the straight section between the two curves after this redesign?

The following table shows the stations and ordinates for a mass diagram. The free-haul distance is 600 ft. Overhaul cost is $12 per station yard. (a) Use the method of moments to compute the additional cost that must be paid to the contractor. (b) Sketch the ground profile if the finished grade of this roadway section is level (0 percent).