No description available.

No description available.

Continuously monitoring and automatically identifying existing problems in traffic signal operation is a challenging and time-consuming task. Although data are becoming available due to the adoption of emerging detection technologies, efforts on utilizing the data to diagnose signal control are limited. The current practices of retiming signals are still periodic and based on several days of aggregated turning movement counts. This dissertation developed a framework of automatic signal operation diagnosis with the aim to support decision-making processes by assessing the signal control and identifying the signal retiming needs. The developed framework used a combination of relatively low-cost data from Wi-Fi sensors and historical signal timing records from existing signal controllers. The development involved applying multiple data matching and filtering algorithms to allow the estimation of travel times of vehicular traversals. The Travel Time Index (TTI) was then used as a measure to assess the traffic conditions of various movements. Historical signal timing records were also analyzed, and an additional signal-timing measure, referred to as the Max-out Ratio (MR), was proposed to evaluate the frequency in which the green time demand of a phase exceeded its preset value. Thresholds for the TTI and MR variables were used as a basis for the diagnosis. This diagnosis first identified the needs for assigning additional green times for individual signal phases. Further assessments were then made to determine whether or not the cycle length for the entire intersection or capacity was sufficient. The developed framework was implemented in a real-world signalized intersection and proved to be capable of identifying retiming needs, as well as providing support for the retiming process. Compared to field observations, the diagnosis results were able to reflect the signal operations of most of the movements during various time periods. Moreover, the flexibility of the developed framework allows users to select different thresholds for various movements and times of day, and thus customize the analysis to agency needs.

Annual average daily traffic (AADT) is used to estimate intersection performance across Kentucky. The Kentucky Transportation Cabinet (KYTC) currently collects AADTs for state maintained roads, but lacks this information on local roads. A method is needed to estimate local road AADTs in a cost-effective and reasonable manner. A literature review was conducted on AADT models and found no models suitable to Kentucky. Therefore an AADT model using non-linear regression was developed for local roads in Kentucky This model divided the state into three regions utilizing Kentucky’s highway districts. This partitioning accounted for geographic and socioeconomic variability across the state. Each regional model relied upon three independent variables: probe count, residential vehicle registration, and curve rating. HERE proprietary probe counts provide tracking visibility on a select portion of vehicles moving across Kentucky highways. Residential vehicle registrations were used to estimate trip generation information. Finally, the curve rating partially indicates accessibility. The models were adjusted to KYTC daily vehicle miles traveled (DVMT) county control totals for local roads. Sensitivity analysis was conducted to examine the impact of model errors for use in intersection safety analysis. Results indicate that the estimates generated can be effectively used for safety assessment and countermeasure prioritization.

New software and technology is making it easier than ever before for public transportation planners to evaluate how quickly residents can reach jobs and other destinations. Because in the past it was difficult to measure access to opportunities, these concepts remained primarily in the theoretical and academic realms of research. This thesis reviews methods that could be used to evaluate routine bus service improvements and performs a comparative analysis of different methods in the context of New Orleans. There are many different variables in how the analysis could be performed, but this thesis focuses on the role that time of day plays in analyzing service changes. The results show that accessibility can be a very useful metric to evaluate the effectiveness of transit service changes. It goes on to explore techniques that could assist transit planners and schedulers to identify service gaps and prioritize service changes.

This project deals with the viability of establishing a staging operation in the Alberton area which will enable Cargo Carriers Limited to improve its service in the distribution of Iscor's steel. This report discusses the logistics of the staging operation and the cost implication : a forecast is made to compare the profitability of the new operation with the existing method distribute tg i teel. Conclusions reached are: - the establishment of a staging operation will provide an improved service to Iscor at the cost of being 7 percent less profitable (in term s of return on turnover). - the cost of establishing a new depot in Alrode for the staging operation will be in the region of R5 000 000, - by shunting nnd stag in g loads o v ern ig h t In A iberton a capital saving of 27 vehicles will be achieved. T h j establishm ent of a sta g in g operation will also provide Cargo C arriers Limited with the following benefits: - improved p ro d u ctiv ity of fleet. - more flexibility of serv ice. - enough room for any fu tu re expansion of depot. - the possibility of obtaining new bu sin ess from th e larg e in d u strial companies which are located near th e new depot. Because of the operational ben efits and im proved custom er serv ice it is recommended th a t Cargo C arriers Limited pro ceed s with the establishm ent of such an operation.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Mavris, Dimitri N.; Committee Member: Baik, Hojong; Committee Member: DeLaurentis, Daniel; Committee Member: Lewe, Jung-Ho; Committee Member: Schrage, Daniel. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Vehicle operating costs are an invaluable tool to transportation engineers, who utilize them in applications such as cost-benefit analyses and utilization pricing. Many of the existing models in use, however, are significantly out-of-date with current technology. Research was undertaken in partnership with the Texas Department of Transportation (TxDOT) to develop a new model of the operating costs associated with Texas vehicle fleets. A vehicle operating cost (Vcost) model was produced which estimates variable and fixed costs associated with both light-duty and heavy-duty vehicles. The model calculates both aggregate fleet costs and costs for individual representative vehicles. An analysis of Texas Vehicles, Titles, and Registration (VTR) records; Weigh-in-Motion data; vehicle counts; and national car sales data was used to generate the breakdown of the Texas fleet of vehicles and to determine representative vehicles. Operational costs for these vehicles fell into two main categories: fixed costs (depreciation, financing, insurance, and other) and variable costs (fuel and maintenance/repair). Relations were determined for each cost category for each representative vehicle over its entire operational age. In the case of heavy-duty vehicles, much of the operational costs information is proprietary and had to be gathered in survey work conducted with other members of a research team. A computer program was written that incorporates the cost relations for the representative vehicles as well as the Texas fleet characteristics in such a way that the user can examine the costs of both an individual vehicle and the aggregate costs associated with a fleet of vehicles. The user can also input a default fleet composition. The model allows users to alter key parameters (such as fuel price, financing rates, insurance costs, or vehicle fuel economies) for future adaptability to a changing economic and technological landscape. The model was developed in parallel with another researcher working on an advanced fuel consumption model, which would later be integrated into to the Vcost model. / text

Thesis (PhDTransportSystemsEngineering)--University of South Australia, 2003.

Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 106-110). Also available in electronic format on the Internet.