Answer Happy

3. After 10 years, the stop-controlled junction in Question 2 will be upgraded into a roundabout as shown in Figure 2. Using the peak hour flow rate in Table 1, project the peak hour flow rate after 10 years using the average annual growth rate of 5.5%. Using the projected peak hour flow rate and the u-turn peak hour flow rates given in Table 2, draw the skeleton diagram to show the origin-destination flow diagram. Subsequently, calculate the reserve capacity of the (10 marks) roundabout. Given: W = 10 m, L = 31.5 m, e₁= 7 m, e₂ = 8 m Table 2: Peak hour flow rate for u-turn movements Flow (vph) Figure 2: Three-legged roundabout Approach South West East 188 196 174