Exploration of trapezoidal flowrate contractions resulting from pavement distress

Highway traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Highway capacity is the apex point of the flow and density curve. The flow and density curve is asymmetric. It has 2 chambers (unconstrained and constrained). Obviously the constraint is capacity. The extent of highway capacity loss depends solely on the degree of traffic flowrate disturbances. Trapezoidal flowrate contraction is a description of the rate of flowrate forward movement within the constrained chamber of flow/density curve. A capacity estimation method was used that is based on extrapolation of the free flow part of the fundamental diagram representing flowrate and density in a 'with and without pavement distress' impact study in Skudai Malaysia. The method applied assumes that the density at capacity is not affected by road distress which implies that capacity losses are fully the result of speed changes. Capacities for two directions of one road section were estimated and compared. Results show that capacities for road section with good and distressed surfaces differ significantly and trapezoidal flowrate contraction ranges from 4m/s to 11m/s depending on the degree of capacity loss.