Multimetric Analysis of a Simulated Mixed Traffic of Motorcycles and Automobiles: Flow, Energy, CO2 and Costs

The fleet of developing countries consists of motorcycles and cars. This heterogeneous traffic condition has its advantages and disadvantages, which results in conflicting points of view (e.g., motorcyclists enjoying a higher mobility while car drivers resent their decreased speed). In this paper, we corroborated the notion that traffic evaluation depends on the chosen metric (e.g., vehicle flow, fuel consumption, monthly costs) and the point of view (driver, rider, and policy makers). To this effect, we studied a mixed traffic condition, considering that the vehicle performance is affected by three scales: engine, vehicle, and traffic. We modeled the engine using empirical correlations of power and energy efficiency, the vehicle based on a balance of propulsive and resistive forces, and traffic with a cellular automata model. We simulated 189 traffic conditions and evaluated vehicle flow, average energy consumption, total CO2 emission of the road, and monthly costs. We also discussed the results from the point of view of the driver, rider, and society. We concluded that the optimal condition depends both on the choice of metric and point of view, and that is not appropriate to use results from homogeneous traffic to analyze heterogeneous traffic conditions, even if both scenarios present the same total vehicle flow.