A highway with a design speed of 100 km/hr is designed with a sag curve connecting a descending gradient of 3% with an ascending gradient of 5%. (A) If comfort is the primary design criterion, assuming a vertical radial acceleration of 0.3 m/s^2 calculate the required length of the sag curve (comfort criterion). (B) If a bridge structure were to be located within the sag curve, with a required clearance height of 5.7 m, then assuming a driver’s eye height of 2 m and an object height of 0.26 m, calculate the required length of the sag curve is stopping sight distance is 215m  (clearance criterion).

As a roadway designer you are asked to design a horizontal curve for a two-lane road that are 12' wide each. There is an enormous boulder in the way of the construction zone and the minimum distance needed to excavate towards to the center must be solved for. The distance is required to sustain a speed of 55mph at a maximum super-elevation of 10%. Find the minimum distance from the boulder to the center of the road that fulfils the design requirement

A vertical curve was designed in 2006 for SSD requirements at a design speed of 120 km/h to connect grades G1 = +1% and G2 = -2%. The curve is to be redesigned for 120 km/h design speed in the year 2050. Vehicle braking technology has advanced such that vehicle deceleration rate has increased by 40% relative to 3.4m/s2 value used in the original design. However, due to the higher percentage of older people in the driving population, design reaction times have increased by 20%. Also, because vehicles have become smaller, the driver’s eye height is assumed to be 0.9 m above pavement. Compute the difference in design curve lengths for the 2006 and 2050 designs. Assume heye =1.08 and hobs = 0.60 m.