Case Studies to Develop a Highway-Rail Grade Crossing Analysis Framework Using Microsimulation

693JJ621C000017There are approximately 126,700 highway-rail at-grade crossings in the U.S. A portion of those involve high-volume public streets where crossing events result in measurable traffic backups and delays to the extent that mitigation efforts are needed. Conventional traffic analysis methods such as those in the Highway Capacity Manual are limited in their ability to quantify the impacts of traffic interruptions due to a train crossing. Microscopic traffic simulation methods are capable of analyzing these events and simulation software has been a part of the practitioner\u2019s toolbox now for 30 years. However, there has been no technical guidance nor consistency on how these tools should be applied to evaluate crossing events. Using microscopic simulation, researchers performed two case studies from which a framework has been developed that can be used by practitioners and decision makers for performing traffic operations analyses of at-grade crossings. The framework offers guidance for a consistent approach to the development and application of such models

CDOT Dynamic Traffic Assignment (DTA) Implementation Plan

PO 401001494This report presents a vision and an implementation plan for region-wide dynamic traffic assignment (DTA) in Colorado. With the proper approach and methods, DTA can be a powerful and cost-effective decision support tool for CDOT\u2019s and MPOs\u2019 transportation planning and engineering responsibilities and activities. In the report, simulation-based DTA models are described, and their key features are explained and placed in the context of current traffic microsimulation and travel demand modeling practices. DTA makes it possible to address numerous traffic management and operations strategies, to improve project evaluation, and, with suitable implementation and application, realize benefits in the form of reduced traffic delay, improved safety, lower greenhouse gas emissions, and greater toll revenues from dynamically-priced facilities. DTA will also reduce costs and improve the quality and consistency of future simulation studies. The report outlines a recommended technical approach to DTA employing regional mesoscopic simulation with capabilities for hybrid mesoscopic-microscopic simulation for increased detail and accuracy when needed. The report provides an implementation plan for realizing the technical approach and capturing the benefits of DTA in metropolitan areas big and small across Colorado. The implementation plan identifies steps, methods, best practices, and recommendations for successful DTA development, calibration, and application

Turning Transportation Planning Data Into Effective Web Sites Giovanni Flammia and Andres Rabinowicz

The Web offers a unique opportunity for State Departments of Transportation and planning agencies to disseminate to large audience interactive results of transportation studies. This paper provides a technical backgrounder about the differences between GIS desktop applications and web mapping applications in the context of transportation planning. In a web mapping application the application server performs all of the computations and manages multiple user sessions. This technical constraint determines what functions are available and how they can be implemented effectively to display interactive maps and reports

A Decentralized and Continuity-Based Algorithm for Delineating Capacitated Shelters' Service Areas

This paper introduces a novel algorithm for delineating mutually exclusive service areas of shelters which have finite capabilities to accommodate residents who are unevenly distributed in space. Minimizing the travel cost and keeping spatial continuity with capability constraint are the convergent objectives of this algorithm. The algorithm partitions an entire residential area into a number of spatial units to handle the unevenness of demand, and employs a shift insertion mechanism to reduce travel cost and to improve the spatial continuity of service areas. A series of experiments and scenarios has been conducted for the city of Memphis, USA, to validate the proposed algorithm. Comparative experiments under different constraints show that the proposed algorithm is a feasible solution for delineating service areas. Various application circumstances (for example, travel-cost calculation methods and the granularity of available demographic data) are discussed to evaluate the algorithm\u27s feasibility. The proposed algorithm can be applied not only to delineating service areas of existing shelters but also to optimizing location allocation of new shelters or other facilities with similar characteristics