en-us Tue, 5 Jun 2012 00:21:48 UTC Inmagic DB/Text WebPublisher http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR233E Mon, 14 May 2012 14:00:00 UTCThis paper describes a data collection methodology to address insufficient data sources for estimation of urban container truck traffic (drayage) volumes. The methodology is sensitive to the characteristics of drayage and offers a systematic approach for acquiring container truck traffic data for constructing models to estimate drayage volumes. The methodology consists of (a) acquiring urban truck traffic estimates and national and provincial- or state-level container traffic databases, (b) characterizing shippers and carriers through field investigations and surveys, and (c) designing a container truck data collection program. Short-term manual truck classification intersection turning movement counts were conducted to obtain body style and axle configuration data for articulated trucks. Temporal expansion factors were developed and applied to short-term count data to produce average daily container truck traffic volume estimates and reveal temporal, physical, and spatial distribution differences between container trucks and other articulated trucks. The paper provides a rationale for selecting count station locations and their temporal characteristics, choosing the number of counts and their duration, determining the types of data to collect, and identifying container generators. The methodology is generally applicable to North American inland port cities. The data feed a model that is intended to assist transportation engineers in understanding urban drayage operations and quantifying the exposure of these trucks. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR234E Mon, 14 May 2012 14:00:00 UTCFreight transportation has a multifaceted impact on the economy, and the importance of understanding freight demand is increasing. There is a significant need to access a wide array of data sources for freight modeling and analysis. However, current data sources are not always easily accessible even with the availability of the Internet. Among the reasons are differing user interfaces, unavailability of data type definition, data format incompatibility, and inability to assess the scope of data conveniently. The repository developed in this study, the California Freight Data Repository, is a user-centered online tool designed from a systems perspective with several objectives. First, it facilitates convenient access, standardized interface, and a centralized location for obtaining freight data. Data dictionaries and lookup tables are provided for each data source to allow users to understand the scope of the data source and to give a clear definition of terms found in the data. A quality assessment summary is also provided to inform users of the strengths and limitations associated with each data source. Second, the repository is equipped with several geographic information system-based visualization tools intended to allow users to perform preliminary evaluation of data to determine their suitability for specific modeling or analysis needs. Third, the repository is designed with a customized search engine to retrieve web resources specifically associated with freight modeling and analysis. This paper presents the metadata architecture used for identifying data sources, the assessment framework used to evaluate selected data sources, and the system and interface design of the California Freight Data Repository. Several use cases are presented to demonstrate the applicability of this resource. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR240E Mon, 14 May 2012 14:00:00 UTCThis paper presents the results of a stated-choice survey design in which reduced information is available about the values of the parameters. The main objective of the survey is to develop discrete choice models to analyze the carrier selection process by shippers. The only information available is the expected sign of the parameter in the utility function. Therefore, the use of a Bayesian approach is necessary in analyzing the efficiency of potential survey designs. The measure of efficiency adopted is the 95th percentile value of the D-error, the determinant of the asymptotic variance-covariance matrix, obtained via Monte Carlo simulation. This measure would maximize the expected gain of information with the experiment. In the survey, the respondents (shippers) will be asked to provide the main carrier's attributes used in the selection process. On the basis of the answers, the survey will be customized to each respondent (situation). In this paper, only the results of the design for situations in which shippers select continuous attributes are presented. An algorithm is developed in a statistical package to search and evaluate the efficiency of 1,000 randomly selected potential survey designs. The algorithm maintains the 10 most efficient designs to be evaluated and uses box plots to identify the most suitable design. The results show that the approach adopted improves the efficiency of the design substantially, which would result in more accurate models from the survey data. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR306E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR307E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR308E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR231E Mon, 14 May 2012 14:00:00 UTCAlthough trucks move larger volumes of goods than other modes of transportation, public agencies know little about their travel patterns and how the roadway network performs for trucks. Trucking companies use data from the Global Positioning System (GPS) provided by commercial vendors to dispatch and track their equipment. This research collected GPS data from approximately 2,500 trucks in the Puget Sound, Washington, region and evaluated the feasibility of processing these data to support a statewide network performance measures program. The program monitors truck travel time and system reliability and will guide freight investment decisions by public agencies. While other studies have used a limited number of project-specific GPS devices to collect frequent location readings, which permit a fine-grained analysis of specific roadway segments, this study used data that involved less frequent readings but that were collected from a larger number of trucks for more than a year. Automated processing was used to clean and format the data, which encompassed millions of data points. Because a performance measurement program ultimately monitored trips generated by trucks as they travel between origins and destinations, an algorithm was developed to extract this information and geocode each truck's location to the roadway network and to traffic analysis zones. Measures were developed to quantify truck travel characteristics and performance between zones. To simplify the process and provide a better communications platform for the analysis, the researchers developed a Google Maps-based online system to compute the measures and show the trucks' routes graphically. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR104E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR204E Mon, 14 May 2012 14:00:00 UTCPerformance Based Standards (PBS) brings an alternative approach to heavy vehicle regulation. It focuses on how well the vehicle behaves on the road, through a set of nationally agreed safety and infrastructure protection standards, rather than how big and heavy (length and mass) it is. Queensland Department of Transport and Main Roads (TMR) encourage innovative vehicle concepts that improve the productivity of road transport, and maintain or improve road safety. Queensland has played a major role in the development of PBS A-double combinations for container transport. The PBS approach for these innovative combinations involved detailed examination of the dynamic performance of the candidate heavy vehicle combinations, and how these vehicles may interact with the existing infrastructure and traffic. Assessing and opening up strategic road networks that unlock the potential for PBS vehicles is seen as a means of addressing increasing road freight. Over 2009 and 2010, TMR undertook a project to assess a key strategic road freight route between Toowoomba and the Port of Brisbane for larger PBS style vehicles that would provide significant productivity increases, particularly for containerised grain for export markets. This paper summarises the procedures and policy considerations developed for providing access for the operation of these 30m long combinations. It also discusses some of the innovative heavy vehicle management practices that enabled the introduction of PBS A-doubles. The productivity and environmental benefits of the operation of PBS A-doubles on the Toowoomba to Brisbane freight corridor are also demonstrated. This project has provided a useful example of the potential for a PBS approach to containerised freight. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR305E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR361E Mon, 14 May 2012 14:00:00 UTCThe report focussed on the extent to which there has been movement on the 23 supply chain blockages identified in the Australian Logistics Council’s report ‘Australia’s Supply Chains – Fixing the Blockages’ (2008). From a review of reports on infrastructure priorities and strategy documents prepared by Infrastructure Australia and submitted to government for consideration, it appears that some progress has been achieved against many of the initial set of 23 blockages identified by ALC Members, including areas of regulatory and institutional reform. However, many seemingly high profile issues do not appear to have shown much progress over the term covered by Infrastructure Australia’s (IA) reports to government. While progress has been achieved, this does not suggest that all blockages have been eliminated to provide a fully integrated and efficient transport system. Further action will be required by all levels of government, with the cooperation of industry, to realise such an outcome over time.