Browsing by Subject "Traffic"

Now showing 1 - 13 of 13
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    Adjusting ITE’s Trip Generation Handbook for urban context
    (Journal of Transport and Land Use, 2015) Clifton, Kelly J.; Currans, Kristina M.; Muhs, Christopher D.
    This study examines the ways in which urban context affects vehicle trip generation rates across three land uses. An intercept travel survey was administered at 78 establishments (high-turnover restaurants, convenience markets, and drinking places) in the Portland, Oregon, region during 2011. This approach was developed to adjust the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip rates based on built environment characteristics where the establishments were located. A number of policy-relevant built environment measures were used to estimate a set of nine models predicting an adjustment to ITE trip rates. Each model was estimated as a single measure: activity density, number of transit corridors, number of high-frequency bus lines, employment density, lot coverage, length of bicycle facilities, presence of rail transit, retail and service employment index, and intersection density. All of these models perform similarly (Adj. R2 0.76-0.77) in estimating trip rate adjustments. Data from 34 additional sites were collected to verify the adjustments. For convenience markets and drinking places, the adjustment models were an improvement to the ITE’s handbook method, while adjustments for restaurants tended to perform similarly to those from ITE’s estimation. The approach here is useful in guiding plans and policies for a short-term improvement to the ITE’s Trip Generation Handbook. The measures are useful for communities seeking to develop local adjustments to vehicle trip rate estimates, and all could be calculated from spatial data available in most locations. The paper concludes with a discussion on what long-term improvements to the ITE’s Trip Generation Handbook might entail, with further implications in planning and practice.
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    Bus Rapid Transit Technologies: A Virtual Mirror for Eliminating Vehicle Blind Zones: Volume 2
    (Center for Transportation Studies, 2005-01) Sergi, Michael Knoll; Donath, Max
    The FTA has identified the concept of Bus Rapid Transit as a means to increase the efficiency of transit operations while maintaining transit’s proven safety record. According to the FTA website www.fta.dot.gov, “BRT combines the quality of rail transit and the flexibility of buses. It can operate on exclusive transitways, HOV lanes, expressways, or ordinary streets. A BRT system combines intelligent transportation systems technology, priority for transit, cleaner and quieter vehicles, rapid and convenient fare collection, and integration with land use policy.” Because of the limited right-of -way available to build new the FTA has identified lane assist as an emerging technology, which the premise behind lane assist technology is to unique environments, such as narrow lanes. Lane assist technology will allow desired higher operating speeds while maintaining the safety of the passengers, BRT public. Vehicle and the motoring BRT vehicles to operate at the increase the safety of BRT vehicles as they operate in the more will enable deployment of BRT systems. (and possibly dedicated) lanes for BRT operations. The third objective will be to develop long term relationships with Metro Transit, the Federal Transit Administration, bus manufacturers, and technology providers to develop and implement strategies to improve transit operations. For instance, improving the ability of a bus driver to merge into and out of traffic is a high priority. Improved bus guidance technology will make bus only shoulders a viable alternative throughout the country. Progress towards meeting this objective has been made, but considerable effort will have to be expended to make lane assist technology ubiquitous throughout the transit industry.
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    Development of Mobile Accessible Pedestrian Signals (MAPS) for Blind Pedestrians at Signalized Intersections
    (Center for Transportation Studies, 2011-06) Liao, Chen-fu; Rakauskas, Michael; Rayankula, Avanish
    People with vision impairment have different perception and spatial cognition as compared to the sighted people. Blind pedestrians primarily rely on auditory, olfactory, or tactile feedback to determine spatial location and find their way. They generally have difficulty crossing intersections due to lack of traffic information at intersections. Among the intersection crossing sub-tasks, locating crosswalk, determining when to cross and maintaining alignment to crosswalk while crossing are the most difficult tasks for the blind and visually impaired. To understand how the blind pedestrians make safe crossing decisions, ten blind and low-vision individuals were interviewed. The purpose of these interviews was to understand the types of information they use while making safe intersection crossings and identify new information types that could assist them. A Mobile Accessible Pedestrian Signals (MAPS) prototype was developed to support decision making at signalized intersections. The MAPS integrates sensors on a Smartphone, Wi-Fi, and Bluetooth technologies, and traffic signal controllers were developed to provide intersection geometry information and Signal Phasing and Timing (SPaT) to pedestrians who are blind at signalized intersections. A single-tap command on the Smartphone screen allows users to request for intersection geometry information, such as street name, direction and number of lanes at a corner of an intersection. A double-tap input while pointing toward desired direction of crossing will confirm the crossing direction, request for pedestrian phase, and the Smartphone application will then wirelessly request for signal timing and phasing information from traffic signal controller.
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    Driving change: Exploring the adoption of multimodal local traffic impact assessment practices
    (Journal of Transport and Land Use, 2021) Combs, Tabitha S.; McDonald, Noreen C.
    Local governments are increasingly recognizing the need to improve multimodal mobility. Using interviews with officials in 36 eastern US communities, we explore factors influencing the adoption of new traffic-impact-assessment (TIA) practices that support multimodal objectives. We focus on communities' motivations and supports for multimodal-oriented practices, as well as challenges they face in adopting these practices. By examining both the prevalence of multimodal-supportive TIA practices adopted by our study communities and the motivations for and challenges to adopting these practices, we identify pathways through which transportation researchers can better support communities' efforts to more closely align their TIA practices with desired multimodal-supportive outcomes.
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    Effects of edge rate on perceived egomotion in a driving environment.
    (2009-12) Rakauskas, Michael E.
    Automobile drivers have a tendency to make judgments of their perceived rate of travel, or egospeed, that are slower than the speed they are actually traveling. This often leads them to drive at faster speeds, which results in increased crash risk for themselves and other vehicles. A driver's egospeed can be affected by visual cues in the environment including Edge Rate (ER) optical effects. The purpose of this research was to examine how speed production would be affected by (1) the presence and distance of roadside (geographic) ER cues; (2) proximal ER cues such as traffic moving at faster, similar, or slower speeds than the driver; and (3) the combined presence of geographic and traffic ER cues. A novel methodology had participants drive at comfortable and ratio speeds while experiencing 10 continuous minutes of each ER condition. Performance was examined in terms of: mean speed choice; ratio speed-production performance (target ratio); speed consistency (speed drift ratio, reliability ratio); and judgments of task difficulty (ease rating). Data suggested that certain cues reduced a driver's comfortable speed of travel: the presence of geographic ER cues; closer-distance geographic ER cues; slower-speed-traffic ER cues; and the pairing of geographic ER with slower-speed-traffic ER cues. Data showed that a reduction in traffic speeds may be produced by increasing the saliency of ER cues in the environment regardless of traffic conditions.
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    Johnson Street Business District Parking Study
    (2007) Rosenberg, Jeff
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    Large urban freight traffic generators: Opportunities for city logistics initiatives
    (Journal of Transport and Land Use, 2015) Jaller, Miguel; Wang, Xiaokun (Cara); Holguin-Veras, Jose
    This paper develops procedures to identify and quantify the role played by large urban freight traffic generators as contributors of truck traffic in metropolitan areas. Although ports, container terminals, and other industrial sites are usually associated with large generations of truck trips, they only represent a small proportion of the total trips produced and attracted in large metropolitan areas. This paper analyzes the importance of other facilities such as ordinary businesses or buildings that individually or collectively (clusters) generate a large proportion of truck traffic. The paper discusses the opportunities of these large traffic generators for city logistics initiatives. In addition, the paper introduces two effective and complementary procedures to identify these generators using freight trip generation models estimated by the authors.
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    The Minnesota Bicycle and Pedestrian Counting Initiative: Implementation Study
    (Minnesota Department of Transportation, 2015-06) Lindsey, Greg; Petesch, Michael; Hankey, Steve
    The Minnesota Bicycle and Pedestrian Counting Initiative: Implementation Study reports results from the second in a series of three MnDOT projects to foster non-motorized traffic monitoring. The objectives were to install and validate permanent automated sensors, use portable sensors for short duration counts, develop models for extrapolating counts, and integrate continuous counts into MnDOT traffic monitoring databases. Commercially available sensors, including inductive loops, integrated inductive loops and passive infrared, pneumatic tubes, and radio beams, were installed both as permanent monitor sites and used for short-duration counts at a variety of locations in cities, suburbs, and small towns across Minnesota. All sensors tested in the study produced reasonably accurate measures of bicycle and pedestrian traffic. Most sensors undercounted because of their inability to distinguish and count bicyclists or pedestrians passing simultaneously. Accuracy varied with technology, care and configuration of deployment, maintenance, and analytic methods. Bicycle and pedestrian traffic volumes varied greatly across locations, with highest volumes being on multiuse trails in urban areas. FHWA protocols were used to estimate annual average daily traffic and miles traveled on an 80-mile multiuse trail network in Minneapolis. Project findings were incorporated in a new MnDOT guidance document, “DRAFT Bicycle and Pedestrian Data Collection Manual” used in statewide training workshops. A major challenge in implementing bicycle and pedestrian traffic monitoring is data management. Years will be required to institutionalize bicycle and pedestrian traffic successfully.
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    Practical Methods for Analyzing Pedestrian and Bicycle Use of a Transportation Facility
    (Minnesota Department of Transportation Office of Research Services, 2010-02) Somasundaram, Guruprasad; Morellas, Vassilios; Papanikolopoulos, Nikolaos P.
    The objective of the project is to analyze existing technologies used for the process of generating counts of bicycles and pedestrians in transportation facilities such as walk and bicycle bridges, urban bicycle routes, bicycle trails etc. The advantages and disadvantages of each existing technology which is being applied to counting has been analyzed and some commercially available products were listed. A technical description of different methods that were considered for vision based object recognition is also mentioned along with the reasons as to why such methods were overlooked for our problem. Support Vector Machines were used for classification based on a vocabulary of features built using interest point detectors. After finalizing the software and hardware, five sites were picked for filming and about 10 hours of video was acquired in all. A portion of the video data was used for training and the remainder was used for testing the algorithm’s accuracy. Results of counts are provided and an interpretation of these results is provided in this report. Upon detailed analysis the reasons for false counts and undercounting in some cases have been identified and current work concerns dealing with these issues. Changes are being made to the system to improve the accuracy with the current level of training and make the system available for practitioners to perform counting.
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    Rab GTPase mediated regulation of the autophagic pathway and mTOR signaling in the larval fat body of Drosophila melanogaster
    (2016-07) Ayala-Navarro, Carlos I
    Autophagy is a conserved lysosomal dependent pathway employed by cells during stress conditions as an alternative source of nutrients to maintain cellular homeostasis and promote survival. The pathway is negatively regulated by the mechanistic target of rapamycin (mTOR) and induced by depletion of nutrients. Over the last decade input in the form of vesicular traffic from an array of cellular organelles (e.g. Golgi, ER, endocytic pathway and mitochondria) has been shown to be required for the delivery of proteins, enzymes and lipids during progression of the autophagic pathway. However, how these organelles switch from their constitutive roles to supply the autophagic pathway with proteins and lipids upon induction is not fully understood. In addition the extent to which these cellular organelles modulate autophagosomal growth and mTOR-Insulin signaling remains incompletely understood. The main goal of this thesis was to uncover novel traffic regulators of the Rab GTPase family required for starvation-induced autophagy in Drosophila fat body cells and evaluate their role in mTOR signaling regulation. To this end we carried a reverse screen using RNAi to knockdown 30 of the 33 Drosophila Rab GTPases. We show Rab 2, 7 and 14 GTPases are required for the induction and growth of autophagosomes and autolysosomal function. Rab5 is required for autophagic vesicle induction and growth, endocytosis and lysosomal maturation. Lastly, that Rab6 is required for the sorting of lysosomal hydrolases, autolysosome turnover and the regulation of mTOR signaling via regulation of the insulin receptor localization in fat body cells. Altogether we uncovered novel regulators in the vesicular traffic regulator Rab GTPase family required for autophagy and mTOR-Insulin signaling regulation in Drosophila.
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    Relationship between urban tourism traffic and tourism land use: A case study of Xiamen Island
    (Journal of Transport and Land Use, 2021) Gao, Yueer; Liao, Yanqing; Wang, Donggen; Zou, Yongguang
    The development of tourism leads to changes in land-use demands and patterns, which are complex and dynamic, in tourist cities. Functional differences in land use produce different travel needs and have different impacts on traffic, especially on tourism. This paper explores the relationship between tourism land use and tourism traffic. Taking Xiamen Island as an example, using multivariable linear regression models, tourism land use is divided into accommodation land use, shopping land use and restaurant land use as the independent variables of the model; and the origin-destination (OD) density of traffic analysis zones (TAZs) during National Day in 2018 (October 1 to 5) is chosen as the dependent variable. To compare the different impacts between tourism land use and tourism traffic during the tourism and non-tourism periods, the non-tourism period (March 11 to 15) is further studied. The results show the following: (1) Xiamen, as a tourism city, has not only regular traffic but also tourism traffic, and traffic during the tourism period is totally different than that in the non-tourism period. (2) Tourism land use has a considerable impact on both tourism traffic and non-tourism traffic, but the impact is greater during the tourism period than the non-tourism period. (3) In the morning peak hour of both the tourism period and the non-tourism period, accommodation land use shows prominent effects on traffic. In the evening peak hour, shopping land use significantly impacts traffic. The study provides a basis for urban tourism land use adjustment to achieve the sustainable development of tourism traffic.
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    Traffic Impacts of Bicycle Facilities
    (Minnesota Department of Transportation, 2017-06) Hourdos, John; Lehrke, Derek; Duhn, Melissa; Ermagun, Alireza; Singer-Berk, Lila; Lindsey, Greg
    Engineers need information about interactions between vehicles and bicyclists to design efficient, safe transportation systems. This study involved a review of design guidelines for bicycle facilities, observation of bicycle-vehicle interactions at nine roadways with different types of bicycle facilities, analysis of results, and description of design implications. Facilities observed included buffered and striped bicycle lanes, sharrows, signed shared lanes, and shoulders of various widths. Driver behaviors were categorized as no change in trajectory, deviation within lane, encroachment into adjacent lane, completion of a passing maneuver, and queuing behind cyclists. Drivers on roadways with bicycle lanes were less likely to encroach into adjacent lanes, pass, or queue when interacting with cyclists than drivers on roadways with sharrows, signs designating shared lanes, or no bicycle facilities. Queueing behind cyclists, the most significant impact on vehicular traffic flows, generally was highest on roads with no facilities or shared facilities without marked lanes. Statistical modeling confirmed the descriptive results. Given an objective of increasing predictability of driver behavior, buffered or striped bicycle lanes offer advantages over other facilities. Sharrows may alert drivers to the presence of cyclists, but traffic impacts on roadways with sharrows may not differ significantly from roadways with no facilities. Signs indicating bicyclists may occupy lanes also may alert drivers to the presence of cyclists, but this study provided no evidence that interactions on roadways marked only with signs differ from roadways with no facilities. From the perspective of reducing potential traffic impacts, bicycle lanes are to be preferred over sharrows or signage.