2. Peak-hour traffic demand between an origin-destination pair is initially 3,500 vehicles. The

two routes connecting the pair have performance functions t₁ = 2 + 3 (x₁/c₁) and t₂ = 4 + 2

(x2/c₂), where the t's are travel times in minutes, the x's are the peak-hour traffic volumes

expressed in thousands, and the c's are the peak-hour route capacities expressed in thousands

of vehicles per hour. Initially, the capacities of routes 1 and 2 are 2,500 and 4,000 xeh/h.

respectively. A reconstruction project reduces capacity on route 2 to 2,000 yeh/h.

Assuming user equilibrium before and during reconstruction, what reduction in total peak-hour

origin-destination traffic flow is needed to ensure that total travel times (summation of all

Xata, where a denotes route) during reconstruction are equal to those before reconstruction?