Traffic Theory

This work introduces the goal of predictability into ground delay program (GDP) cost optimization under capacity uncertainty for a single airport case. This is accomplished by modifying traditional GDP delay cost functions so that they incorporate predictability. Extra premiums are assigned to unplanned delays, and planned but unincurred delays, due to their unpredictability. Two stochastic GDP models are developed based on deterministic queueing theory and continuous approximation to estimate the delay components in the cost functions: a static no-revision model and a dynamic model...

Several factors contribute to traffic congestion on highway facilities including adverse weather conditions. However, the extent of weather impacts on traffic flow and congestion delay on freeways is not fully known. This study analyzed an extensive set of historical traffic data from the state of California to gain a better understanding of the proportion of traffic delay that can be directly attributed to weather. A congestion estimation model was developed to estimate vehicle delays directly attributed to rain on 17 urban freeway corridors. It was found that delay due to rain ranged...

Queue spillbacks are a major problem in urban signalized arterials because such spillbacks can lead to gridlock and excessive delays. Several methods based on fixed-location detector data have been proposed to identify the occurrence of queue spillbacks and implement signal control strategies to mitigate their impacts. This paper presents two queue spillback detection methods based on connected vehicle (CV) or probe data. The first method requires only the use of CV data and is based on the notion that nonequipped vehicles in queue that arrive after the last CV-equipped vehicle can be...

In oversaturated urban traffic conditions when traffic demand exceeds capacity at signalised intersections, queues fail to clear during the allocated green times. Once a queue reaches the upstream intersection in an arterial, a queue spillback occurs that reduces the upstream link capacity. To mitigate the negative impacts of spillbacks, this article introduces a real-time adaptive traffic signal control method for global management of spillbacks along signalised arterials. The key idea of the proposed method is to implement a real-time partitioning of the arterial to detect critical...