A section of road needs to be realigned because it includes a 'broken back' curve. The realignment will replace the broken back curve with a single left-hand horizontal circular curve. To help with the design of the circular curve, the following information has been supplied:

The road is located in a rural area with a speed environment of 90 km/hr and the terrain is considered to be mountainous.

> The road must be suitable for use by all types of vehicles, including design prime movers and semi-trailers.

> Transition curves are not needed in the design.

> Icy conditions are not experienced on the road surface during winter.

> The normal rate of rotation will be present along the superelevation development length and normal crossfall will exist on each tangent.

The left-hand horizontal circular curve will start at chainage 260.00 metres, it will be 460.00 metres long and it must have a radius of 250.00 metres.

> The superelevation will be fully developed on the tangents.

Using this information,complete the following:

(a) Draw a sketch, including labels, showing the existing situation and what the realignment is going to achieve. (4 Marks) (b) Calculate the maximum superelevation required for the left-hand horizontal circular curve and explain whether, or not, the design of the curve is appropriate for the location and conditions associated with the road. Show all of your workings. (5 Marks) (c) Using the maximum superelevation value calculated in (b) above, determine the superelevation development length associated with the left-hand horizontal circular curve. (2 Marks) (d) Using the superelevation development length calculated in (c) above, determine the chainage where the superelevation associated with the left-hand horizontal circular curve reaches 5.24%. (5 Marks)