Analysis of traffic flow with mixed manual and semi-automated vehicles

The paper analyzes the effects on traffic flow characteristics and environment when semi-automated vehicles with automatic vehicle following capability (in the same lane) operate together with manually driven vehicles. We show that semi-automated vehicles do not contribute to the slinky effect phenomenon observed in today´s highway traffic when the lead manual vehicle performs smooth acceleration manoeuvres. We demonstrate that semi-automated vehicles smooth traffic flow by filtering the response of rapidly accelerating lead vehicles. Using simulations we show that the fuel consumption and pollution levels present in manual traffic simulated using a car following model that models the slinky effect behavior observed in manual driving can be reduced during rapid acceleration transients by 7.3% and 3.8%-47.3% respectively, due to the presence of 10% semi-automated vehicles. The data obtained are qualitatively valid and demonstrate the beneficial effect of semi-automated vehicles in mixed traffic in improving air quality and fuel consumption