Stability Analysis of Connected and Automated Vehicles to Reduce Fuel Consumption and Emissions

Obtaining an optimal stability condition is very important to benefit traffic flow operations for a mix of connected and automated vehicles (CAVs) and regular vehicles. In view of multiple spatial anticipations of CAV car-following models, this paper presents a stability analysis method for mixed CAV flow from the perspective of the uniform local platoon. Transfer function theory was used to derive the stability criterion of the uniform local platoon, based on which a stability chart of equilibrium speeds and CAV feedback coefficients was calculated. Numerical simulations were also performed on a segment of highway with an on-ramp using car-following models to evaluate the impacts of the stability analysis on fuel consumption and emissions [carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx)]. The stability chart indicates that by controlling CAV feedback coefficients, the optimal stability condition can be obtained, in which the uniform local platoon remains stable for all driving speeds. Moreover, the stability analysis method can reduce fuel consumption and traffic emissions. (C) 2018 American Society of Civil Engineers.