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Book Variable Speed Limit System Cost Benefit Analysis

Download or read book Variable Speed Limit System Cost Benefit Analysis written by and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The variable speed limit (VSL) system is designed to display both the maximum and minimum speed boundaries based on measured traffic and environmental conditions. In addition, short driver information messages can be displayed to warn of downstream conditions. The VSL can be installed to operate independently (Isolated), in a series of stations (Linked), as a component of a larger management system (Integrated), and in the future as part of an "In-Vehicle" component to provide all types of driver information (In-Vehicle). This analysis compares the four types of VSL systems to the existing "fixed" speed limit system which can display only one speed for all conditions

Book Work Zone Variable Speed Limit Systems

Download or read book Work Zone Variable Speed Limit Systems written by Nicholas J. Fudala and published by . This book was released on 2010 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variable speed limit (VSL) systems have been used in a number of countries, particularly in Europe, as a method to improve flow and increase safety. VSLs use detectors to collect data on current traffic and/or weather conditions. Posted speed limits are then dynamically updated to reflect the conditions that motorists are actually experiencing. Presenting drivers with speed limits that are appropriate for current conditions may reduce speed variance, a concept sometimes called speed harmonization. If properly designed, VSL systems have been shown to reduce crash occurrence and can also reduce system travel time through increased uniformity in traffic speeds. High-volume urban work zones tend to be prone to congestion and safety problems, and VSLs may be one way to ameliorate these issues. VSLs were recently installed at a high-volume, congested urban work zone located on I-495 (the Capital Beltway, hereinafter the Beltway) between the Springfield Interchange in Springfield, Virginia, and the Virginia-Maryland state line on the Woodrow Wilson Memorial Bridge. VSL signs were activated in late July 2008, but initial evaluations of the system showed inconclusive effects. Changing site conditions made a direct before-and-after evaluation of the system deployed in the field problematic, and some problems with the control algorithm were also noted. Given the difficulties in evaluating the system deployed in the field, a calibrated simulation of the site was constructed to assess the effects of the VSL system on traffic operations and safety surrogate measures. The simulation platform also provided an opportunity to examine a number of system configurations to assess how changes in system design and driver behavior might affect a variety of measures. The results indicated that the VSL could create substantial improvements in traffic operations provided the demand did not exceed capacity by too large a margin. The location of the VSL signs played an important role in operational performance. The study recommends that the Virginia Department of Transportation continue to pursue this technology but carefully scrutinize algorithm design and VSL sign placement. Further, a cost/benefit analysis indicated that VSLs may be most appropriate for long-term applications.

Book Dynamic Variable Speed Limit Control

Download or read book Dynamic Variable Speed Limit Control written by Petros A. Ioannou and published by . This book was released on 2012 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Public Roads

Download or read book Public Roads written by and published by . This book was released on 1989 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Notes on the State of the Art of Benefit cost Analysis as Related to Transportation Systems

Download or read book Notes on the State of the Art of Benefit cost Analysis as Related to Transportation Systems written by Joseph D. Crumlish and published by . This book was released on 1966 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review of benefit-cost analysis as a tool for evaluating alternative courses of action describes the technique, discusses a number of benefit-cost studies, and indicates the difficulties inherent in this area of applied economics. * The author concentrates on the application of the technique to large scale transport problems, reviews the literature and indicates in his conclusions where the technique can be helpful and where there is little chance for its success.

Book Effects on Speeds of a Rural Variable Speed Limit System

Download or read book Effects on Speeds of a Rural Variable Speed Limit System written by Emily C. Layton and published by . This book was released on 2011 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Speed limits are generally created for ideal road conditions. When road conditions deteriorate, speed limits tend to become unreasonable, and enforcement of safe driving becomes difficult. Variable speed limit (VSL) systems are used to adjust speeds in accordance with the changing conditions in an attempt to reduce the variation of speeds among all vehicles. This research highlights the findings from the variable speed limit system in place along the Elk Mountain Corridor of I-80 in Southeastern Wyoming during the first and second full winter seasons of VSL implementation. Specifically this research focuses on speeds and variations of speed and the effect the VSL system has had on individual vehicles. The objective of this research was to determine if the VSL system was effective in reducing speeds and speed variation during adverse conditions. Further, this analysis attempts to determine the effect of the VSL system on driver behavior. The VSL system was effective at reducing speeds when properly implemented, reduced speed variation as well. Drivers respond differently to different levels of VSL implementation.

Book Costs and Benefits of General Speed Limits

Download or read book Costs and Benefits of General Speed Limits written by Karl Krell and published by European Conference of Ministers of Transport ; [Washington, D.C. : sold by OECD Publications Center]. This book was released on 1978 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Developing Crash Modification Factors for Variable Speed Limits

Download or read book Developing Crash Modification Factors for Variable Speed Limits written by Raul Avelar and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to perform rigorous safety effectiveness evaluations of variable speed limit (VSL) implementation on freeway corridors. To accomplish this objective, the research team compiled safety data from Virginia, Wyoming, and Georgia and used an interrupted time series study design (with a comparison group for Georgia). The team analyzed data using logistic and negative binomial generalized estimating equations models. The results from Wyoming and Georgia produced evidence of significant reductions in several types of crashes. The research team found total crash reductions of 34.4 and 29.2 percent associated with VSL installations in Wyoming and Georgia, respectively. The economic evaluation for these two States generally indicated larger benefits than costs. For Georgia, the estimated benefit-cost (B/C) ratio was 40.38. The economic analysis for Wyoming yielded a more modest B/C ratio of 9.05, though still indicating benefits outweighing VSL installation costs. Results from Virginia were inconclusive as the analysis found no statistical evidence of a change in overall safety. The inconclusiveness of these results is possibly due to the sample size of the after period, the small amount of time the system was active, and the manner in which the VSL was used in the corridor for enhancing safety during adverse weather conditions.

Book Report on Activities Under the Highway Safety Act of 1966

Download or read book Report on Activities Under the Highway Safety Act of 1966 written by United States. National Highway Traffic Safety Administration and published by . This book was released on 1970 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Evaluation of Variable Speed Limits Using a Genetic Algorithm Approach to Calibrate a VISSIM Model

Download or read book Evaluation of Variable Speed Limits Using a Genetic Algorithm Approach to Calibrate a VISSIM Model written by Brian Joseph Schaefer and published by . This book was released on 2010 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The variable speed limit (VSL) system has been adopted on more and more roadways across the globe as an engineering tool for controlling traffic flow, particularly during congestion situations. An important and fundamental question raised among traffic engineers is: Are the costs of installing and operating variable speed limits really justified? In order to answer this question, this thesis measures the effectiveness of the VSL system applying the VISSIM microscopic simulation model to a non-recurrent congestion situation. For the analysis, a section of interstate was modeled in VISSIM and calibrated so that the simulated results closely reproduce the observed data collected from traffic detectors. The calibration process is accomplished using a genetic algorithm (GA) programmed in MATLAB. Once the interstate system is calibrated to the static speed limit condition, the VSL system is portrayed on the model by temporarily blocking lanes to measure the effectiveness of VSL during an incident situation. Multiple incident locations and different VSL configurations are tested to investigate various possible forms of reality. The simulated results of with-VSL and without-VSL systems were compared and evaluated. The results show that no significant changes in travel times are observed, but queue lengths and fuel consumption decrease by 10-20% and 3-5% respectively. The speed variances upstream of the incidents also decreased 10-25% depending on location, which in the end may lead to fewer crashes. Before a VSL system is constructed a study should be conducted to determine if the cost of installing and maintaining the system is justified by the benefits. The benefits of a VSL system include a decrease in fuel consumption as well as a decrease in the deviation of speeds, potentially leading to a reduction in crashes. Further studies need to be done to determine exactly how much the number of crashes could potentially be reduced. If a governing authority has the means for a VSL system they could potentially be justified by a reduction in crashes on the roadway, but the breadth of this thesis does not have enough evidence to support the case that there will be a definite reduction in the number of crashes"--Abstract, leaf iii.

Book Variable Speed Limit System System Design

Download or read book Variable Speed Limit System System Design written by Edmond L. Seguin and published by . This book was released on 1987 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination for driver requirements for use in the design of variable speed limit systems was the focus of two human factors studies. Driver preferences and opinions relating to message content, display attributes, operational modes, display location, usage guidelines, and the like were addressed in the first study. This report on the second study deals with the determination of the maximum distance between display components of variable speed systems. The FHWA Highway Simulator (HYSIM) was used to examine driver retention through analysis of the driver's ability to recall speed limit information which changed as a function of distance during a pre-programmed highway scenario. Sixty-three subjects completed the experimental trip. Based on an 85th percentile criterion, a recommendation is made for a maximum distance betwen displays of 5 miles.

Book Variable Traffic Signs 1989 1994

Download or read book Variable Traffic Signs 1989 1994 written by and published by . This book was released on 1994 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The 55 Mile Per Hour National Maximum Speed Limit

Download or read book The 55 Mile Per Hour National Maximum Speed Limit written by Donald Gordon Griffin and published by . This book was released on 1984 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: