Download or read book Validation of Arterial Travel time Estimation Models Using Field Data and Simulation written by Michael P. Dixon and published by . This book was released on 2007 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Validation of Arterial Travel Time Models Using Field Data and Simulation written by Jesse Birchman and published by . This book was released on 2006 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field Validation of Speed Estimation Techniques for Air Quality Conformity Analysis written by and published by . This book was released on 2004 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The air quality conformity analysis process requires the estimation of speeds for a horizon year on a link-by-link basis where only a few future roadway characteristics, such as forecast volume and capacity, are known. Accordingly, the Virginia Department of Transportation (VDOT) has at its disposal a variety of techniques, known as "speed post processors" that estimate average travel speeds on each roadway link based on projected volumes from urban travel demand models. Using field data collected at 15 sites in Richmond and Charlottesville, the accuracy of three post-processing techniques was determined by comparing predicted average travel speed and measured average travel speed. On average, the mean absolute errors for the post processors were relatively similar, ranging between 8 and 12 mph. The post processors overpredicted speeds on some links and underpredicted speeds on others; the average of these positive and negative errors for the post processors was between 2 and 6 mph. Based on MOBILE6 simulation runs with Richmond area data, the differences in speed predictions from the speed post processors would have led to at most a 2.5 percent difference in estimated emissions of volatile organic compounds. All three post processors would have underestimated Richmond area emissions of nitrogen oxides by less than 2 percent. Although differences in national fleet data and Richmond fleet data hamper a direct comparison, additional MOBILE6 simulation results with national data suggest these Richmond results are indicative of the sensitivity of MOBILE6 emissions to changes in estimated vehicle speed. For a class of nine suburban arterial roadways, this study showed that the error associated with any of the post processors could be reduced through judicious altering of the default capacity. This reduction was effected relatively easily by modifying the group capacity rather than computing a capacity for each link. Therefore, although any of the three post processors can be used, this study recommends, in the short term, sampling a few links for each roadway category to determine the appropriate capacity for the category, following an approach similar to that presented in this study. For arterial facilities in particular, this study showed what has been anecdotally known in practice: average travel speeds are affected not just by volume but also by other factors such as signal timing. For this study, this proved to be both a curse and a blessing. On the one hand, the twin facts that the speed post processors are volume dependent and that volume explained only a small amount of the variation in travel speed meant that field results did not show the sensitivity to volume expressed in the literature. On the other hand, because average travel speeds tended to stay within a moderate range, this study showed how better calibration with simple post processors can lead to predictions that are within 5 mph of observed data.

Download or read book Travel Time Estimation from Loop Detector Data for Advanced Traveler Information Systems Applications written by and published by . This book was released on 1994 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real time Estimation of Arterial Performance Measures Using a Data driven Microscopic Traffic Simulation Technique written by Dwayne Anthony Henclewood and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic congestion is a one hundred billion dollar problem in the US. The cost of congestion has been trending upward over the last few decades, but has experienced slight decreases in recent years partly due to the impact of congestion reduction strategies. The impact of these strategies is however largely experienced on freeways and not arterials. This discrepancy in impact is partially linked to the lack of real-time, arterial traffic information. Toward this end, this research effort seeks to address the lack of arterial traffic information. :To address this dearth of information, this effort developed a methodology to provide accurate estimates of arterial performance measures to transportation facility managers and travelers in real-time. This methodology employs transmitted point sensor data to drive an online, microscopic traffic simulation model. The feasibility of this methodology was examined through a series of experiments that were built upon the successes of the previous, while addressing the necessary limitations. The results from each experiment were encouraging. They successfully demonstrated the method's likely feasibility, and the accuracy with which field estimates of performance measures may be obtained. In addition, the method's results support the viability of a "real-world" implementation of the method. An advanced calibration process was also developed as a means of improving the method's accuracy. This process will in turn serve to inform future calibration efforts as the need for more robust and accurate traffic simulation models are needed. :The success of this method provides a template for real-time traffic simulation modeling which is capable of adequately addressing the lack of available arterial traffic information. In providing such information, it is hoped that transportation facility managers and travelers will make more informed decisions regarding more efficient management and usage of the nation's transportation network.

Download or read book Urban and Regional Transportation Modeling written by Der-Horng Lee and published by Edward Elgar Publishing. This book was released on 2004-01-01 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'This collection in honor of David Boyce contains genuinely interesting and quality papers that reflect the diversity of interests of the honoree. David Boyce has made a number of significant contributions at the interface of transportation and regional science. He has been a pioneer of injecting rigor and consistency into spatial analysis. The papers here both reflect the ethos of this copious body of analysis and take it further in extensions and applications. It will prove to be an enduring source of ideas and insight.' - Kenneth Button, George Mason University, US

Download or read book Estimation of Travel Time on Signalized Arterial Highway Corridor written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this research was to estimate travel time on a signalized arterial highway corridor using empirical data. Two different methods or techniques were explored; (a) a simulation model NETSIM, which is a comprehensive microscopic traffic simulation model for surface streets; and (b) an analytical approach for estimating average green times of vehicle-actuated signals using bunched exponential model. Field data were collected on an arterial highway (OH-48) located in Lebanon, Ohio. The travel time affected by traffic signals, co-ordination of the signal system, volume or rate of flow of traffic, and geometry of the arterial corridor was considered. NETSIM was used to simulate traffic flow conditions and estimate arterial travel time for the same time period. The NETSIM output of average travel time was compared against the actual travel time recorded on the field. The results of NETSIM study were found to be satisfactory and acceptable for the existing signalized arterial highway conditions. However, further work is required to test the simulation model for greater variability in field observed travel time. Additionally in this paper, a set of formulations to estimate average green times of vehicle-actuated signals employing bunched exponential model were verified for field conditions. Using these formulations, an analytical method for estimating arterial travel time has been demonstrated.

Download or read book Transportation Research Record written by and published by . This book was released on 1997 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Transportation Research Progress written by Filip Gustavsson and published by Nova Publishers. This book was released on 2008 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with new research in the fields of passenger and freight transportation modes: policy analysis, formulation and evaluation; planning; interaction with the political, socioeconomic and physical environment; design, management and evaluation of transportation systems.

Download or read book Real Time Estimation of Arterial Travel Time and Operational Measures Through Integration of Real Time Fixed Sensor Data and Simulation written by Michael P. Hunter and published by . This book was released on 2012 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimating Arterial Link Travel Time Using Loop Detector Data Phase II written by H. Michael Zhang and published by . This book was released on 1998 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes efforts towards developing an arterial travel time model using data from inductive loop detectors and traffic controllers. The model consists of two parts. including the speed estimated from the volume and occupancy measured by detectors and the speed estimated based on critical volume/capacity ratio.

Download or read book Arterial Link Travel Time Estimation Using Loop Detector Data written by H. Michael Zhang and published by . This book was released on 1997 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Arterial Link Travel Time Model with Consideration of Mid block Delays written by Alexandra Kondyli and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: This thesis presents analytical models for estimating arterial travel time with consideration of delays at mid-block locations. The mid-block delays are defined as the delays that through drivers experience due to turning maneuvers of either the other major stream vehicles ahead that exit from the arterial or the minor stream vehicles that enter the arterial. These delays typically occur at the intersections with driveways. Volume and travel time data are collected in two-lane two-way and two-lane one-way arterials. These data are used for the development of simulation models and the expansion of the database through simulation. The generated data are used for the development of analytical equations of mid-block delay through regression. The final regression equations provide estimation of arterial mid-block delay depending on the conditions that the arterial operates (congested - uncongested conditions).

Download or read book Estimating and Measuring Arterial Travel Time and Delay written by Henry X. Liu and published by . This book was released on 2012 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: To estimate arterial travel time/delay, the key element is to estimate intersection queue length, since travel time, delay, and level of services can be easily derived from queue length information. In this study, we developed a new traffic flow model, named shockwave profile model (SPM), to describe queuing dynamics for congested arterial networks. Taking advantage of the fact that traffic states within a congested link can be simplified as free-flow, saturated, and jammed conditions, the SPM simulates traffic dynamics by analytically deriving the trajectories of four major shockwaves. This model is particularly suitable for simulating congested traffic especially with queue spillover. In the SPM, a novel approach is proposed as part of the SPM, in which queue spillover is treated as either extending a red phase or creating new cycles. Since only the essential features, i.e. queue build-up and dissipation, are considered, the SPM significantly reduces the computational load and improves the numerical efficiency. We further validated the SPM using real-world traffic signal data collected from a major arterial in the Twin Cities. The results clearly demonstrate its effectiveness and accuracy. This model can be applied to estimate arterial travel time and delay and optimize signal timing in real time.

Download or read book Modeling Travel Time in Urban Arterial Networks with Time variant Turning Movements Using State space Neural Networks written by Timothy Joseph Likens and published by . This book was released on 2007 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Final Report to the Florida Department of Transportation Systems Planning Office on Project Travel Time Reliability Models for Freeways and Arterials written by Lily Elefteriadou and published by . This book was released on 2007 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Travel Time and Average Speed to Evaluate Urban Arterial Performance written by Harini Mangilipally and published by . This book was released on 2012 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic system performance can be measured in various ways, but from the user perspective, congestion is the major criterion. To assess the congestion levels for arterials with numerous signalized intersections and access points, travel time and speed are considered as the key performance measures. Collecting these data for all links in the transportation network is expensive, laborious and time-consuming. Literature, however, documents limited efforts to model and assess performance based on these measures for urban arterials.The objective of this research is to develop and validate models to estimate these key measures for assessment of urban arterial street performance. Road network characteristics, traffic characteristics, traffic control devices and signal parameters were considered as explanatory variables to evaluate delay in link travel time and average network speed. Five models: 1) average speed including length, 2) average speed excluding length, 3) delay in travel time using the basic equation, 4) delay in travel time using Bureau of Public Roads (BPR) equation with standard a and P parameters, and 5) delay in travel time using BPR equation with a and P parameters obtained from a regional travel demand forecasting model were developed. Models were developed including and excluding intercept to show the effect of intercept or constant in the model. Results indicate that average speed models are comparatively better statistical models than travel time models to assess urban arterials performance. The average speed models including length are comparatively better statistical models than the models excluding length.To closely understand the effect of signal spacing on link travel time and average travel speed, statistical analysis on the influence of signal spacing on link travel time and average travel speed was also done and the results show that the increase in the number of signals per mile has a negative effect on arterial performance.