A rolling-horizon quadratic-programming approach to the signal control problem in large-scale congested urban road networks

The paper investigates the efficiency of a recently developed signal control methodology, which offers a computationally feasible technique for real-time network-wide signal control in large-scale urban traffic networks and is applicable also under congested traffic conditions. In this methodology, the traffic flow process is modeled by use of the store-and-forward modeling paradigm, and the problem of network-wide signal control (including all constraints) is formulated as a quadratic-programming problem that aims at minimizing and balancing the link queues so as to minimize the risk of queue spillback. For the application of the proposed methodology in real time, the corresponding optimization algorithm is embedded in a rolling-horizon (model-predictive) control scheme. The control strategy’s efficiency and real-time feasibility is demonstrated and compared with the Linear-Quadratic approach taken by the signal control strategy TUC (Traffic-responsive Urban Control) as well as with optimized fixed-control settings via their simulation-based application to the road network of the city centre of Chania, Greece, under a number of different demand scenarios. The comparative evaluation is based on various criteria and tools including the recently proposed fundamental diagram for urban network traffic

Urban Goods Movement and Local Climate Action Plans: Assessing Strategies to Reduce Greenhouse Gas Emissions from Urban Freight Transportation

This report examines how freight transport/goods movement has been addressed in U.S. city climate action planning. Transportation generally is a major contributor of greenhouse gas (GHG) emissions, and freight transport represents a growing component of transportation’s share. Almost all climate action plans (CAPs) address transportation generally, but we wished to focus on efforts to reduce GHG emissions from freight transport specifically. We analyzed 27 advanced local CAPs to determine the degree to which freight transport was targeted in goals and strategies to reduce GHG emissions. We found only six CAPs that included direct measures or programs to reduce freight emissions. Many of the CAPs mentioned general transportation objectives such as lowering vehicle miles traveled or reducing emissions from city-owned vehicle fleets, but most did not include strategies or actions that explicitly targeted freight transport. We identified the specific strategies and actions that cities are taking to address GHG emissions from freight transport, such as working with the freight community to promote anti-idling and encourage transitions to electric and alternative fuel delivery vehicles. We also analyzed freight transport plans relevant for the same cities, and found that most do not explicitly mention reducing GHG emissions. Most of the freight plans are focused on improving reliability and efficiency of freight movement, which would likely have the ancillary benefit of reducing GHG emissions, but that goal was not explicitly targeted in most of these plans. Based on our findings, we recommend that cities specifically target freight transport goals and strategies in their CAPs and better coordinate with planners developing freight transport plans to identify GHG emission reduction approaches

Using a cognitive prosthesis to assist foodservice managerial decision-making

The artificial intelligence community has been notably unsuccessful in producing intelligent agents that think for themselves. However, there is an obvious need for increased information processing power in real life situations. An example of this can be witnessed in the training of a foodservice manager, who is expected to solve a wide variety of complex problems on a daily basis. This article explores the possibility of creating an intelligence aid, rather than an intelligence agent, to assist novice foodservice managers in making decisions that are congruent with a subject matter expert\u27s decision schema