48,454 research outputs found

    Cost Estimate Modeling of Transportation Management Plans for Highway Projects, Research Report 11-24

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    Highway rehabilitation and reconstruction projects frequently cause road congestion and increase safety concerns while limiting access for road users. State Transportation Agencies (STAs) are challenged to find safer and more efficient ways to renew deteriorating roadways in urban areas. To better address the work zone issues, the Federal Highway Administration published updates to the Work Zone Safety and Mobility Rule. All state and local governments receiving federal aid funding were required to comply with the provisions of the rule no later than October 12, 2007. One of the rule’s major elements is to develop and implement Transportation Management Plans (TMPs). Using well-developed TMP strategies, work zone safety and mobility can be enhanced while road user costs can be minimized. The cost of a TMP for a road project is generally considered a high-cost item and, therefore, must be quantified. However, no tools or systematic modeling methods are available to assist agency engineers with TMP cost estimating. This research included reviewing TMP reports for recent Caltrans projects regarding state-of-the-art TMP practices and input from the district TMP traffic engineers. The researchers collected Caltrans highway project data regarding TMP cost estimating. Then, using Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) software, the researchers performed case studies. Based on the CA4PRS outcomes of the case studies, a TMP strategy selection and cost estimate (STELCE) model for Caltrans highway projects was proposed. To validate the proposed model, the research demonstrated an application for selecting TMP strategies and estimating TMP costs. Regarding the model’s limitation, the proposed TMP STELCE model was developed based on Caltrans TMP practices and strategies. Therefore, other STAs might require adjustments and modifications, reflecting their TMP processes, before adopting this model. Finally, the authors recommended that a more detailed step-by-step TMP strategy selection and cost estimate process be included in the TMP guidelines to improve the accuracy of TMP cost estimates

    Tribal Corridor Management Planning: Model, Case Study, and Guide for Caltrans District 1, Research Report 10-01

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    In Northern California, tribal governments and personnel of the California Department of Transportation (Caltrans) District 1, have applied innovative context-sensitive solutions to meet a variety of transportation challenges along state highways that traverse tribal lands. This report describes and discusses the efforts under way and offer suggestions for continuing and extending these initiatives through the development of Tribal Corridor Management Plans (TCMPs). The methods employed in this project are multidisciplinary and include: (1) content analysis of existing corridor management plans; (2) literature review to identify “best practices;” (3) participant observation; (4) interviews with local stakeholders; (5) focus group interviews with Caltrans personnel; and (6) landscape analysis. This study’s authors conclude that Caltrans District 1 staff and tribal governments share common goals for highway operations; however, progress —while significant—has been somewhat hampered by geographic and administrative challenges. It is recommended that Caltrans and the tribes seek early and frequent communication and collaboration to overcome these obstacles. Further, they identify several examples of non-standard design elements that could be incorporated into highway improvements to enhance local sense of place among both residents and travelers. A preliminary TCMP for the segment of State Route 96 that lies within the boundaries of the Hoopa Valley Indian Reservation is presented as an example. Beyond its role as a guide for initiating tribal corridor projects within Caltrans District 1, the report should prove instructive for any efforts to enhance sense of place within transportation byways, particularly in Native communities

    On the use of Fixed Trip Matrices for the Evaluation of Urban Highway Schemes

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    This paper begins with a summary of the theoretical background to the question of fixed or variable trip matrices and briefly reviews current UK advice and practice. The main bulk of the paper is a review of published evidence as to whether network improvements do or do not affect trip matrices. The conclusion is that there is strong evidence of local land use changes, particularly adjacent to major new intersections or access points. However, it is clear that any new development is dependent on the existence of a capacity for relocation or growth in the local economy and a not unfavourable stance by the local planning authority. In the absence of new land development, however, there is little published evidence of changes in trip matrices following network improvements. The conclusion drawn from this evidence, from public interest in the question of generated traffic, and from the lack of reliable forecasting models, is that sensitivity analyses should be carried out to determine the possible effects of changes in the trip matrix before any decision is taken to ignore them

    Traffic flow modeling and forecasting using cellular automata and neural networks : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Computer Science at Massey University, Palmerston North, New Zealand

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    In This thesis fine grids are adopted in Cellular Automata (CA) models. The fine-grid models are able to describe traffic flow in detail allowing position, speed, acceleration and deceleration of vehicles simulated in a more realistic way. For urban straight roads, two types of traffic flow, free and car-following flow, have been simulated. A novel five-stage speed-changing CA model is developed to describe free flow. The 1.5-second headway, based on field data, is used to simulate car-following processes, which corrects the headway of 1 second used in all previous CA models. Novel and realistic CA models, based on the Normal Acceptable Space (NAS) method, are proposed to systematically simulate driver behaviour and interactions between drivers to enter single-lane Two-Way Stop-Controlled (TWSC) intersections and roundabouts. The NAS method is based on the two following Gaussian distributions. Distribution of space required for all drivers to enter intersections or roundabouts is assumed to follow a Gaussian distribution, which corresponds to heterogeneity of driver behaviour. While distribution of space required for a single driver to enter an intersection or roundabout is assumed to follow another Gaussian distribution, which corresponds to inconsistency of driver behavior. The effects of passing lanes on single-lane highway traffic are investigated using fine grids CA. Vehicles entering, exiting from and changing lanes on passing lane sections are discussed in detail. In addition, a Genetic Algorithm-based Neural Network (GANN) method is proposed to predict Short-term Traffic Flow (STF) in urban networks, which is expected to be helpful for traffic control. Prediction accuracy and generalization ability of NN are improved by optimizing the number of neurons in the hidden layer and connection weights of NN using genetic operations such as selection, crossover and mutation

    Maritime Commerce in Greater Philadelphia: Assessing Industry Trends and Growth Opportunities for Delaware River Ports

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    Maritime Commerce in Greater Philadelphia: Assessing Industry Trends and Growth Opportunities for Delaware River Ports is an evaluation of existing port conditions along the Delaware River and market-driven opportunities for expansion. The report includes an economic impact analysis, Delaware River port descriptions, global trends, and recommended strategies for ports growth. Key findings include:Region-wide port activity generates 69millionintaxrevenuesforstategovernmentsacrossGreaterPhiladelphiaandmorethan69 million in tax revenues for state governments across Greater Philadelphia and more than 11 million in Philadelphia Wage Tax revenues.Each on-site port job supports two jobs from port activity and employee spending. Total regional port-related employment is 12,000+ jobs.Delaware River ports import nearly 1/2 of the nation's cocoa beans, almost 1/3 of the bananas, and a 1/4 of all fruit and nuts.Growing maritime commerce in Greater Philadelphia will require collaboration among Delaware River ports to leverage existing strengths and strategically invest in regional infrastructure improvements
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