Colorado Departmant of Transportation report CDOT-2011-13
Date: October 2011
Author(s): Clevenger,CM; Ozbek,ME
The purpose of this study is to review existing Environmental Tracking Systems (ETSs) used by other select state Departments of Transportation (DOTs), as well as the existing Environmental Commitment Tracking System (ECTS) currently in use by Colorado Department of Transportation (CDOT) in an effort to determine which system would be the most beneficial for long-term implementation at CDOT. The findings of this study identify the system that best meets CDOT?s needs for an ECTS with the ultimate purpose of adopting such a system.
Colorado Department of Transportation report CDOT-2011-12
Date: September 2011
Author(s): Mallele,J; Gotlif,A; Littleton,P; Sadasivam,S; Darter,MI;
This study evaluated the longitudinal joint tie bar system currently used by Colorado Departmant of Transportation (CDOT), examining the criteria for proper use of tie bars and determining the maximum number of lanes that can be tied together without negatively impacting the concrete pavement structure. An improved mechanistic-empirical tie bar design method was developed. Tie bar design tables with recommended bar size and spacing were provided for each combination of pavement base types, CDOT concrete mixes, and weather stations. Field studies were conducted to investigate longitudinal joint performance and further evaluate the impact of factors related to design and construction practices.
Florida Department of Transportation report BDK82 977-01
Date: September 2011
Author(s): Sando,T; Moses,R
This study analyzes the influence of several site characteristics on the operational behavior of motorists when passing bicyclists on wider outside through lanes. Several measures of effectiveness were used in this analysis, including: lateral separation between the motor vehicle and bicyclist; motor vehicle shift to the inside lane; motor vehicle outside through lane usage; and motor vehicle speeds before, during and after passing bicyclists. Regression analysis was used to examine the lateral separation between the motor vehicle and bicyclist, vehicle lateral shift to the inside lane, and motor vehicle outside through lane usage. Motor vehicle speeds were analyzed using a paired-t test. The results show that motorists pass closer to bicyclists when a bicyclist is a male, the outside through lane is narrower, motor vehicles are in the adjacent inside lanes, and the overtaking motor vehicle is smaller. This study also developed crash modification factors (CMFs) for asymmetric curb and gutter four-lane roadways with a flush, two-way left-turn lane (TWLTL) and raised median.
TRB?s Transit Cooperative Research Program (TCRP) Synthesis 92
Author(s): McCollum,B; Berrang,SA
The purpose of this synthesis was to examine and document the current state of the practice in transit asset condition management. Transit asset management is defined here as a strategic planning process that supports informed capital investment planning and programming. The report?s objective is to provide transit agencies and their federal, state, and local funding partners with a review of current practices in hopes of encouraging industry-wide discussion on standards and the data needed to measure conditions and use the information in making effective investment decisions.
New Zealand Transport Agency research report 449
Date: October 2011
Author(s): Kingham,S; Taylor,K; Koorey,G
This research investigated what type of cycling infrastructure would encourage ?new cyclists? (ie people who either do not currently cycle at all, or people who do not currently cycle for utilitarian trips) to use cycling as their mode of transport for daily activities in New Zealand. The research involved undertaking an international literature review followed by national surveys and Christchurch-based focus groups, to gain an understanding of some of the motivations and barriers associated with utilitarian cycling, and to evaluate a range of cycling facilities. The research showed that safety was the most significant issue for potential cyclists.
University of Michigan Transportation Research Institute report UMTRI-2011-43
Date: October 2011
Author(s): Sivak,M; Schoettle,B
The age distribution of drivers has major implications for vehicle demand, transportation safety, and environmental consequences of personal transportation. This study examined the recent changes in the percentage of persons with a driver?s license in 15 countries as a function of age. The countries included were Canada, Finland, Germany, Great Britain, Israel, Japan, Latvia, the Netherlands, Norway, Poland, South Korea, Spain, Sweden, Switzerland, and the U.S.A. The results indicate two patterns of change over time. In one pattern (observed for eight countries), there was a decrease in the percentage of young people with a driver?s license, and an increase in the percentage of older people with a driver?s license. In the other pattern (observed for the other seven countries), there was an increase in the percentage of people with a driver?s license in all age categories.
US Federal Highway Administration report FHWA-HRT-10-066
Date: October 2011
Author(s): Carvalho,R; Ayres,M; Shirazi,H; Selezneva,O; Darter,M
The primary focus of this research was to determine the effects of design and construction features, such as overlay thickness and mix type, presence of milling, and type of restoration, on pavement response and performance and to establish their importance in the prediction of future performances of rehabilitated pavements. Long-Term Pavement Performance program Specific Pavement Study (SPS)-5 and SPS-6 experiments provided information to obtain a better understanding of the effects of design and construction features on pavement response and performance of rehabilitated flexible and rigid pavements. The research findings provided guidance to identify appropriate features and rehabilitation alternatives for different pavement types and recommendations for improving data collection activities.
US Federal Highway Administration report FHWA-SA-11-36
Date: July 2011
This primer presents an introduction to the topic of addressing safety as part of the environment analysis process, as directed by the National Environmental Policy Act (NEPA). It presents practitioners with basic concepts for including meaningful, quantitative analysis of project safety issues and for taking advantage of the latest tools, research, and techniques for improving road safety within a project scope. The primer highlights the opportunity and benefits of linking safety planning to the environmental analysis at every stage of the NEPA process.
TRB National Cooperative Highway Research Program (NCHRP) Web-Only Document 181
Date: September 2011
Author(s): Sturm,TW; Ettema,R; Melville,BW
This report reviews the present state of knowledge regarding bridge-abutment scour and the veracity of the leading methods currently used for estimating design scour depth. It focuses on research information obtained since 1990, which is to be considered in updating the scour estimation methods that are recommended by AASHTO, and used generally by engineering practitioners. Though considerable further progress has been made since 1990, the findings indicate that several important aspects of abutment scour processes remain inadequately understood and therefore, are not included in current methods for scour depth estimation. The state-of-art for abutment scour estimation is considerably less advanced than for pier scour.
US Federal Highway Administration report FHWA-HOP-11-032
Date: July 2011
Author(s): Bauer,JK; Smith,MC; Pecheux,KK
This practitioner?s guide is a collection of the observed successes and lessons learned from four metropolitan regions as they developed Regional Concepts for Transportation Operations (RCTOs), a management tool used by planners and operations practitioners to define a strategic direction for implementing effective regional transportation management and operations in a collaborative manner. This document provides information on how to develop and implement an RCTO effectively and efficiently by highlighting practices that have been used successfully to overcome challenges by the four implementing regions that forged ahead into this new territory. This guide offers lessons from these pioneering sites that can help other implementing regions to select the methods that are most effective in improving regional transportation system performance.
US Federal Highway Administration report FHWA-HRT-11-064
Date: November 2011
The purpose of this guidebook is to provide technical advice on the selection and use of traffic analysis tools and methods in a manner that promotes consistency over the course of the project development life cycle. Terminology and processes contained in this guidebook are a composite of the experiences of and approaches used by transportation agencies across the country for instructive and consistency purposes. When using this guidance, individual agencies will need to consider how their own terminology, processes, and procedures correspond to those contained in this document.
Florida Department of Transportation report
Date: November 2011
Author(s): Catal?,M; Downing,S
The development of Google's free online transit trip planner has been one of the most exciting developments in transit for many years. Transit agencies that store trip information into the General Transit Feed Specification (GTFS) file format and forward the data to Google's transit team will have a robust, recognizable online trip planner for free. This project identified opportunities to use GTFS data to support service planning and operational activity. The opportunities are limited to service-level evaluations, given the static nature of the GTFS data. Nonetheless, GTFS data can be used to support service planning efforts. Furthermore, the project identified opportunities to supplement the GTFS with performance-related information and developed a prototype application that integrated GTFS data with an automatic passenger counter (APC).
US Strategic Highway Research Program 2 report S2-L06-RR-2
Author(s): Parsons Brinkerhoff; Delcan
George Mason University School of Public Policy
Housman and Associates
The purpose of this guide is to support transportation agencies in developing institutional arrangements suitable to the special demands of congestion management, now emerging as a new transportation agency priority. In particular, the strategy conventions appropriate to effective management of nonrecurring congestion (NRC) present new challenges for agency policy, organization and staffing, resources, and partnerships, as well as for basic agency culture and leadership. This guide focuses on these special institutional challenges in the form of a change management tool called the Institutional Capability Maturity Model.
Iowa Highway Research Board (IHRB) Project TR-575
Date: June 2011
Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of structural health monitoring (SHM) of highway infrastructure systems, including improved system reliability, improved longevity and enhanced system performance, improved safety against natural hazards and vibrations, and a reduction in life cycle cost in both operating and maintaining the infrastructure. Advancements in MEMS technology and wireless sensor networks provide opportunities for long-term, continuous, real-time structural health monitoring of pavements and bridges at low cost within the context of sustainable infrastructure systems. The primary objective of this research was to investigate the use of MEMS in highway structures for health monitoring purposes. This study focused on investigating the use of MEMS and their potential applications in concrete through a comprehensive literature review, a vendor survey, and a laboratory study, as well as a small-scale field study.
US Federal Highway Administration report FHWA-HRT-11-062
Date: November 2011
Plate girder bridges are usually fabricated from painted carbon steels or unpainted weathering steels. Weathering steels, including the modern high-performance steels, offer the lowest lifecycle cost (LCC) over the design life of the bridge because ongoing maintenance due to steel deterioration is not necessary in most service environments. However, in areas where a bridge is subject to high time-of-wetness or high chloride exposures (i.e., coastal areas or areas where large quantities of deicing salt are used), weathering steels are not effective because the protective patina does not develop, and the steel has a high corrosion rate. In these conditions, structural stainless steel ASTM A1010 (UNS S41003) provides sufficient corrosion protection so that painting is not necessary, and the bridge structure is maintenance-free during its design life. The initial cost of stainless steel is more than twice the cost of carbon or weathering steel. Reducing the cost of stainless steel would improve the LCC of bridges in severe corrosion service conditions. This study was undertaken to identify steels with lower potential cost than ASTM A1010 that could be candidates for bridge construction while still providing low corrosion rates.
US Federal Highway Administration report FHWA-HOP-12-005
Date: December 2011
Author(s): Mallela,J; Sadasivam,S
On-site construction activities can result in significant mobility and safety impacts to road users. The presence of work zone can also result in inconvenience to local business and community, noise and environmental impacts. Work zone road user costs (WZ RUC) provide the economic basis for quantifying these adverse impacts which can then be used for effective decision-making to improve work zone mobility and safety. This report provides practitioners with information on WZ RUC analysis concepts and their applications using case studies drawn from real world projects. WZ RUC primarily refers to monetized components of mobility and safety impacts; increasingly, non-monetary and qualitative components, such as environmental, business, and societal impacts, are being utilized. In this report, each of the monetary components is explored and the computations of these components are illustrated using examples.
Traffic Congestion: Road Pricing Can Help Reduce Congestion, but Equity Concerns May Grow
US Government Accountability Office report GAO-12-119
Date: January 2012
The US Department of Transportation (DOT) approves all congestion pricing projects on roadways that receive federal funds and provides grants for project studies, implementation, and evaluation. DOT?s largest programs for congestion relief, the Urban Partnership Agreement and Congestion Reduction Demonstration programs, have provided grant funds totaling nearly $800 million since 2006 to six metropolitan areas to implement pricing and other strategies. DOT requires sponsors of congestion pricing projects to monitor and evaluate performance and, for High Occupancy Toll (HOT) lanes when applicable, ensure that a federal standard for minimum traffic speeds is met. The 14 congestion pricing projects that have current and complete evaluations generally show that pricing can help reduce congestion, although other results are mixed, and not all possible relevant impacts have been assessed.