Investigating Impacts of Pickup-delivery Maneuvers on Traffic Flow Dynamics

Even if urban logistic has been extensively investigated in the literature, its effects on traffic flow dynamic remain mostly unknown. This paper aims to assess the impact of pickup-delivery trucks on traffic conditions. To this end, we resort to a theoretical but realistic urban arterial where deliveries are completed in double-park. The study first focuses on traffic flowing at capacity and determines the analytical formulation of the effective capacity when neglecting the effects of traffic signals. This formulation only depends on the characteristics of the arterial, the average time headway between truck arrivals and the average stop duration. It turns out that the pickup-delivery maneuvers strongly reduce the capacity. Then, this modeling framework is extended to other traffic conditions. The use of the macroscopic fundamental diagram (MFD) makes it possible to incorporate effects of traffic signals. To this end, an existing MFD estimation method is adapted to the case of double-park deliveries. The comparison of the MFD estimates highlights that logistic activities have a major impact for traffic conditions near the maximal capacity. It confirms that creation of dedicated delivery areas and related logistic policies (pre-booked area, off-pick hours deliveries, etc.) are very promising solutions to improve both the efficiency of the transportation network and the logistic system.