Transportation Intelligence

Volume 9 Number 6

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December 2011

Environment

Safety

Structures

Administration

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Guide to Sustainable Transportation Performance Measures
This document describes opportunities to incorporate environmental, economic, and social sustainability into transportation decision-making through the use of performance measures. Performance measures allow decision-makers to quickly observe the effects of a proposed transportation plan or project or to monitor trends in transportation system performance over time. This document provides examples of best practices in sustainable transportation performance measurement that are being applied across the country. (US Environmental Protection Agency report, August 2011, 58p.)

Predicting Walkability
This research provides a number of mathematical formulas for predicting the quality of the walking environment from the perspective of the user using operational and physical variables. The formulas were derived by combining the perception data gathered from participants in the community street reviews with measurements of the walking environment. The two main areas that were researched to enable the derivation of formulas were:
- when walking along the road (path length)
- when crossing the road (road crossing).
This research describes the process for obtaining the data and deriving the formulas, and recommends the formulas most suitable for practitioner use. This research and the background resource material can be referenced at www.levelofservice.com. (New Zealand Transport Agency research report 452, August 2011, 114p.)

Environment (voir aussi Environnement)

Sustainable Roadside Design and Management for Urban Freeways in Western Washington
This report addresses the question: What does it take to achieve and maintain sustainable urban roadside restoration projects in Western Washington that provide for necessary roadside functions at lowest lifecycle costs? It makes recommendations under five categories: general, agency communication and process, design, construction, and maintenance. It identifies two major problems common to urban roadsides: the establishment of transient encampments and intense invasive weed pressures. Urban roadside environments are extremely varied and serve many functions; therefore, the report does not recommend a single type of roadside planting or maintenance suitable for all situations. Integrated Vegetation Management is a key tool for planning and implementing urban roadside maintenance. (Washington State Department of Transportation report WA-RD 774.1, July 2011, 116p.)

Flooded Bus Barns and Buckled Rails: Public Transportation and Climate Change Adaptation
The objective of this project is to provide transit professionals with information and analysis relevant to adapting U.S. public transportation assets and services to climate change impacts. Climate impacts such as heat waves and flooding will hinder agencies’ ability to achieve goals such as attaining a state of good repair and providing reliability and safety. The report examines anticipated climate impacts on U.S. transit and current climate change adaptation efforts by domestic and foreign transit agencies. It further examines the availability of vulnerability assessment, risk management, and adaptation planning tools as well as their applicability to public transportation agencies. The report provides examples of adaptation strategies and discusses how transit agencies might incorporate climate change adaptation into their organizational structures and existing activities such as asset management systems, planning, and emergency response. By focusing specifically on public transportation, and the unique assets, circumstances, and operations of that mode, the report supplements transportation sector wide studies whose scopes did not allow for more in-depth treatment of transit. (US Federal Transit Administration report 0001, August 2011, 128p.)

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Safety (voir aussi Sécurité)

Evaluation of Safety Strategies at Signalized Intersections
This report presents crash modification factors (CMFs) for safety strategies at signalized intersections. CMFs are a tool for quickly estimating the impact of safety improvements. The report will be of particular interest to safety practitioners responsible for programming and implementing highway safety improvements at intersections. (TRB’s National Cooperative Highway Research Program (NCHRP) Report 705, 2011, 48p.)

Strategies for Reducing Pedestrian and Bicyclist Injury at the Corridor Level
This study was funded by the California Department of Transportation (Caltrans) to develop methods for identifying sites where there is potential for significant reductions in pedestrian and bicyclist injury. Several approaches for identifying sites with high potential for reducing pedestrian and bicyclist injury were evaluated and compared, a framework was developed for conducting benefit-cost analyses, and a prototype was developed for a training protocol for conducting analyses of pedestrian and bicyclist safety in a corridor or network. The basic principle followed is that sites with the most potential for reducing injury are those sites where the most injuries can be prevented per dollar spent. Several approaches to developing statistically stable estimates are explained and compared: (i) extend the number years for both the baseline and follow-up periods, (ii) expand the size of the target sites considered, and (iii) apply Bayesian methods to include a modeled estimate of risk in the calculation. (California Department of Transportation report CA11-1214, July 2011, 74p.)

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Structures (voir aussi Ouvrages d'art)

Development of Steel Design Details and Selection Criteria for Cost Effective and Innovative Steel Bridges in Colorado
This research focuses on finding a method for creating cost effective and innovative steel bridges in Colorado. During the research, a software package was created at Colorado State University that takes user inputted data and outputs the lightest wide flange shape that will satisfy the loading. Once the program was completed, design charts and design tables were created for several one, two, and three span steel bridges. Overall, this research has provided CDOT and others who will use the software or design charts with a tool that will facilitate the construction of innovative steel girder bridges. (North Dakota State University.Upper Great Plains Transportation Institute report MPC11-243, July 2011, 151p.)

Acceptance Procedures for New and Quaility Control Procedures for Existing Types of Corrosion-Resistant Reinforcing Steel
As the Virginia Department of Transportation (VDOT) continues to move forward with implementing the use of corrosion-resistant reinforcing (CRR) bars, it is important for VDOT to have a means of characterizing the candidate bars as well as ensuring that the quality of approved CRR bars is preserved. The purpose of this study was to provide VDOT’s Materials Division with a method/specification for evaluating CRR bars. The study determined that visual assessment cannot be relied on to determine bar type. Further, steel fabricator markings cannot be relied on to identify the type of steel. However, magnetic sorting provides a quick and easy method for differentiating between magnetic and nonmagnetic alloys. If more quantitative results are required, X-ray fluorescence provides a practical and much-needed method for positively identifying bars. (Virginia Center for Transportation Innovation and Research report FHWA/VCTIR 11-R21, June 2011, 80p.)

Tool for Analysis of Early Age Transverse Cracking of Composite Bridge Decks
Computational methods and associated software were developed to compute stresses in high performance (HP) concrete composite bridge decks due to temperature, shrinkage, and vehicle loading. The structural analysis program uses a layered finite element model. A composite bridge specimen was built in the structures testing lab in Clarkson University with thermocouple and strain gage instrumentation. After monitoring temperatures and strains for 28 days, the test specimen was loaded by a concentrated load applied by universal testing machine. Cracking under loading was observed and monitored. Software predictions were compared with test data. A one-day training course was conducted in Albany for NYSDOT engineers on August 3, 2011 to communicate the research findings and recommendations as well as provide training for the use of the developed software. (New York State Department of Transportation Research project SPR-06-37 (C-06-37) - Final Report, 29 August 2011, 167p.)

Replacing Thermal Sprayed Zinc Anodes On Cathodically Protected Steel Reinforced Concrete Bridges
This research aimed to address questions underlying the replacement of arc-sprayed zinc anodes on cathodically protected steel reinforced concrete bridges and to develop a protocol to prepare the concrete surface for the new anode, through a combination of literature review, practitioner surveys, laboratory studies, and field investigation (Pier 9 of the Yaquina Bay Bridge, Oregon). The following recommendations were made for old anode removal and surface preparation before new anode application: use a reasonably low air pressure and a reasonably hard and dense abrasive material for sandblasting; have a reasonably thin coating per pass during arc-spray operations; and have a slightly thinner overall Zn coating layer (15-17 mils vs. the currently used 17 mils). It is also desirable to have concrete with good surface cohesion strength and a minimum of 150 psi initial bond strength. For existing concrete with an equivalent electrochemical age of more than 8 years, the reaction layer should be completely removed prior to profiling and arc spraying. (Oregon Department of Transportation report FHWA-OR-RD- 12-02, August 2011, 201p.)

Investigation of Best Options for Using Scrap Tires in Highway Noise Barriers
In Colorado, approximately 60 million scrap tires have been stockpiled and approximately 4.5 million scrap tires are generated annually. Colorado Department of Transportation (CDOT) has goals and policies to promote sustainability/recycling and receives requests for more traffic noise barriers than can be funded. CDOT identified an opportunity to combine these two topics by investigating new ways to incorporate scrap tires into highway noise barriers. This research project reviewed potential noise barrier materials made from scrap tires, selected a material for field testing, designed and built a test barrier at the designated site using the material, and monitored barrier performance for one year. The material selected was a railroad tie replacement made from scrap tire treads. (Colorado Department of Transportation report CDOT-2011-8, June 2011, 104p.)

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Administration (voir aussi Administration)

State DOT Public Transportation Performance Measures: State of the Practice and Future Needs
State departments of transportation (DOTs) are increasingly using performance measures to improve their planning, construction, and operations and in response to greater need for accountability. Typical practices for public transportation performance measures are oriented to collection and reporting of data on operations performance via metrics for issues such as ridership and service cost effectiveness. In the context of the expanded reliance on performance management that is anticipated with reauthorization, there is a need for more effective use of public transportation performance measures to support state DOT investment decision-making. The purpose of this digest is to provide more information on performance measures and performance management approaches that can be used by state DOTs in relation to public transportation programs. (TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 361, September 2011, 44p.)

Marginal Cost Pricing and Subsidy of Transit in Small Urban Areas
This study analyzes economies of scale and density as a rationale for subsidizing transit agencies in small urban areas. A long-run cost model is estimated using data from 2006 to 2009 for 168 transit agencies that directly operated fixed-route bus service in small urban areas. Using vehicle revenue miles as transit output, results show that small urban transit agencies experience economies of scale and density. A full cost model is estimated that includes the addition of external costs and benefits. Results are then used to estimate the optimal fare, which is equal to marginal social cost of service. The needed subsidy is calculated as the difference between the revenue generated by the optimal fare and that needed to maintain efficient levels of production. A survey was conducted that found that close to half of transit agencies in small urban areas have either reduced service or increased fares over the last two years, and the main reason for these actions has been a decrease in operational funding. (North Dakota State University.Upper Great Plains Transportation Institute report, September 2011, 44p.)

Travel Demand Modeling for the Small and Medium Sized MPOs in Illinois
Travel demand modeling (TDM) is an important tool in the transportation planning community. Several small (50,000< population <200,000) and medium (200,000 <population <500,000) sized Metropolitan Planning Organizations (MPOs) in the state of Illinois are unable to utilize TDM tools primarily due to lack of available resources and guidelines at the regional and state level. This study sought to establish the framework necessary for the development, maintenance, and application of small and medium sized MPOs’ TDMs. This study established a framework for developing travel demand models at the MPO regional level considering their limited available resources. As an important part of this study, a statewide group, the Illinois Modeling Users Group (IL-MUG) was created to support, set standards and guide the development, implementation, and maintenance of travel demand models in small and medium sized MPOs in Illinois. (University of Illinois at Urbana-Champaign.Illinois Center for Transportation Studies report FHWA-ICT-11-091, September 2011, 123p.)

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