Trajectory-Based Measurement of Signalized Intersection Capacity

2019 ◽  
Vol 2673 (10) ◽  
pp. 370-380 ◽  
Author(s):  
Walid Fourati ◽  
Bernhard Friedrich
Keyword(s):  
Cycle Time ◽  
Degree Of Saturation ◽  
Limiting Factor ◽  
Signal Timing ◽  
Flow Rates ◽  
Practical Applications ◽  
Road Intersections ◽  
Good Signal ◽  
Saturation Flow ◽  
Over Time

Capacities of road intersections are a limiting factor and crucial for the performance of road networks. Therefore, for purposes of intersection design and of optimal signal timing, numerous methodologies have been proposed to either estimate or directly measure the capacity of single movements at road intersections. However, both model-based estimation and direct measurement suffer from the large effort that is needed to gather the relevant data. Even worse, once the data are collected they only represent a snapshot of the capacity over time. This paper proposes an alternative approach to estimate capacity of signalized road intersections over time using only automatically generated trajectories of probe vehicles. The obtained capacity can be used to evaluate the effective degree of saturation using real demand, or to assess hypothetic different conditions in demand or signaling. The cyclic operation of signalized intersections allows for the accumulation of trajectories, and thus in practical applications for the compensation of potentially low penetration rates. Within a sequential process the intersection’s cycle time and the approach green time and saturation flow rates are determined. The determination of the cycle time and the green times is based on an existing approach. The derivation of the saturation flow rates relies on its direct dependency to the saturation time headway and uses two parameters to be calibrated. Testing with a commercial dataset on an intersection in Munich produced a good signal timing estimation and saturation flow values that are comparable to a calculation based on the German guideline.

scholarly journals Analisis Waktu Lampu Hijau, Kapasitas Kendaaran dan Derajat Jenuh di Simpang Empat Bersinyal

2019 ◽  
Vol 3 (1) ◽  
pp. 55
Author(s):  
Ana Komari ◽  
Heribertus Budi Santoso
Keyword(s):  
Cycle Time ◽  
Negative Impact ◽  
Red Light ◽  
Green Light ◽  
Degree Of Saturation ◽  
Saturation Degree ◽  
The North ◽  
Light Yellow ◽  
Saturation Flow ◽  
Vehicle Capacity

Congestion has a negative impact on motorists during certain hours. Therefore it is necessary to do an analysis related to traffic with the aim to find out the optimum time of green light, vehicle capacity and degree of saturation. Observations were carried out in the collection of data related to the cycle time of green light, yellow light and red light. Data was collected for 60 minutes at an intersection on Jalan Veteran (east), Jalan Veteran (west), Jalan Kawi and Jalan Penanggungan, Kota Kediri, using the Webster method. Data is processed in terms of saturation flow, traffic flow rate, lost time, optimum cycle time, effective green time, total effective green time, green light time for each phase, actual green time, capacity of each crossing arm and degree of saturation. The results of the study are in accordance with the objectives of the actual green time on the Veteran Road from the east by 10 seconds with a capacity of 389 (kend / hour), degree of saturation 0.93, Veteran Road from the west by 11 seconds with a capacity of 357 (vehicle / hour) , saturation degree 1,07, Jalan Kawi from the north for 8 seconds, with a capacity of 260 (kend / hour), saturation degree 1.21 and a Penanggungan from the south for 11 seconds, with a capacity of 357 (kend / hour), saturation degree 1.12.Keyword : Congestion, Webster, Capacity, Saturated degree Kemacetan menimbulkan dampak negatif bagi pengendara kendaraan di jam – jam tertentu. Oleh karena itu perlu dilakukan analisis terkait lalu lintas dengan tujuan untuk mengetahui waktu optimum lampu hijau, kapasitas kendaraan dan derajat jenuh. Dilakukan observasi yaitu pengambilan data terkait siklus waktu lampu hijau, lampu kuning dan lampu merah. Dilakukan pengambilan data selama 60 menit di persimpangan pada Jalan Veteran (timur), Jalan Veteran (barat), Jalan Kawi dan Jalan Penanggungan, Kota Kediri, menggunkan metode Webster. Data diolah terkait arus jenuh, tingkat arus lalu lintas,  waktu hilang, waktu siklus optimum, waktu hijau efektif, waktu hijau efektif total, waktu lampu hijau tiap fase, waktu hijau aktual, kapasitas tiap lengan persimpangan dan derajat jenuh. Hasil penelitian sesuai dengan tujuan yaitu waktu hijau aktual yang pada Jalan Veteran dari arah timur sebesar 10 detik dengan kapasitas 389 (kend/jam), derajat jenuh 0,93,  Jalan Veteran dari arah barat sebesar 11 detik dengan kapasitas 357 (kend/jam), derajat jenuh 1,07, Jalan Kawi dari arah utara sebesar 8 detik, dengan kapasitas 260 (kend/jam), derajat jenuh 1,21 dan Penanggungan dari arah selatan sebesar 11 detik, dengan kapasitas 357 (kend/jam), derajat jenuh 1,12.  Kata Kunci: Kemacetan, Webster, Kapasitas, Derajat jenuh

Impact of Turning Lane Storage Length and Turning Proportions on Throughput at Oversaturated Signalized Intersections

2021 ◽  
pp. 036119812110171
Author(s):  
A. M. Tahsin Emtenan ◽  
Christopher M. Day
Keyword(s):  
Flow Rate ◽  
Cycle Length ◽  
Signal Timing ◽  
Real World Data ◽  
Left Turn ◽  
Common Response ◽  
Cycle Lengths ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
Timing Strategies

During oversaturated conditions, common objectives of signal timing are to maximize vehicle throughput and manage queues. A common response to increases in vehicle volumes is to increase the cycle length. Because the clearance intervals are displayed less frequently with longer cycle lengths and fewer cycles, more of the total time is used for green indications, which implies that the signal timing is more efficient. However, previous studies have shown that throughput reaches a peak at a moderate cycle length and extending the cycle length beyond this actually decreases the total throughput. Part of the reason for this is that spillback caused by the turning traffic may cause starvation of the through lanes resulting in a reduction of the saturation flow rate within each lane. Gaps created by the turning traffic after a lane change may also reduce the saturation flow rate. There is a relationship between the proportions of turning traffic, the storage length of turning lanes, and the total throughput that can be achieved on an approach for a given cycle length and green time. This study seeks to explore this relationship to yield better signal timing strategies for oversaturated operations. A microsimulation model of an oversaturated left-turn movement with varying storage lengths and turning proportions is used to determine these relationships and establish a mathematical model of throughput as a function of the duration of green, storage length, and turning proportion. The model outcomes are compared against real-world data.

TRANSFORMING THE CHARACTER OF THE UPPER MISSISSIPPI RIVER

2021 ◽  
Vol 40 (1) ◽  
pp. 102-129
Author(s):  
KRISTAN COCKERILL
Keyword(s):  
Nineteenth Century ◽  
Seventeenth Century ◽  
Mississippi River ◽  
River Management ◽  
Late Nineteenth Century ◽  
Upper Mississippi River ◽  
Flow Rates ◽  
Specific Language ◽  
Late Nineteenth ◽  
Over Time

ABSTRACT Despite the long-understood variability in the Mississippi River, the upper portions of the river have historically received less attention than the lower reach and this culminated in the lower river dominating twentieth century river management efforts. Since the seventeenth century, there have been multiple tendencies in how the upper river was characterized, including relatively spare notes about basic conditions such as channel width and flow rates which shifted to an emphasis on romantic descriptions of the riparian scenery by the mid-nineteenth century. Finally, by the late nineteenth century the upper river was routinely portrayed as a flawed entity requiring human intervention to fix it. While the tone and specific language changed over time, there remained a consistent emphasis that whatever was being reported about the river was scientifically accurate.

scholarly journals Metrological performance of single-jet water meters over time

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Carmen Virginia Palau ◽  
Juan Manzano ◽  
Iban Balbastre Peralta ◽  
Benito Moreira de Azevedo ◽  
Guilherme Vieira do Bomfim
Keyword(s):  
Measurement Error ◽  
Water Consumption ◽  
Operating Conditions ◽  
Economic Losses ◽  
Flow Rates ◽  
Metrological Operation ◽  
Operation Period ◽  
Single Jet ◽  
Water Meters ◽  
Over Time

To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

scholarly journals Evaluasi Kinerja Apill dan Geometrik Simpang 3 Sungai Bengkel Kota Bengkalis

2021 ◽  
Vol 18 (2) ◽  
pp. 197-206
Author(s):  
Nursafika Syafika ◽  
Muhammad Idham
Keyword(s):  
Cycle Time ◽  
Slow Motion ◽  
Public Works ◽  
Degree Of Saturation ◽  
Traffic Light ◽  
Traffic Jam ◽  
The North ◽  
Calculation Results ◽  
Bottle Neck ◽  
Intersection Geometry

Third junction of Sungai Bengkel was a Signalized Intersection which a hasn’t have traffic jam ,which has three approach, are North approach, West approach and East approach. However, the alinyemen for the North approach has problems that make it difficult for vehicles, especially four-wheelers to turn because the effect bottle neck resulting in the slow motion of the vehicle and change of phase time . the problem solving, the evalution of traffic light and intersection geometry were carried out by widening  the alinyemen for the North approach and East approaches and doing changes in cycle time. The purpose of evaluating the performance of traffic light and Geometrics at the third intersection of Sungai Bengkel is to determine the value of the degree of saturation and to know the performance of the intersection.At the intersection planning, it refers to the PKJI 2014 for Intersection Performance, while for the Geometrics it refers to Module 4 of the Ministry of Public Works and Public Housing on Geometric Planning of Plane Intersections.Based on  the calculation results of the Sungai Bengkel junction performance indicate that, the degree of  saturation  < 0.85,which is 0.529 for North,  0.537 for East, and 0.570  for West .With the radius is 15 m, and the cycle  time of traffic light 50 second, with the delay time  as long as 17 second/pcu

scholarly journals Design and Validation of a Multi-Point Injection Technology for MR-Guided Convection Enhanced Delivery in the Brain

2021 ◽  
Vol 3 ◽  
Author(s):  
Kayla Prezelski ◽  
Megan Keiser ◽  
Joel M. Stein ◽  
Timothy H. Lucas ◽  
Beverly Davidson ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Low Flow ◽  
Limiting Factor ◽  
Volume Distribution ◽  
Convection Enhanced Delivery ◽  
Flow Rates ◽  
Point Injection ◽  
Subcortical Regions ◽  
Injection Technology

Convection enhanced delivery (CED) allows direct intracranial administration of neuro-therapeutics. Success of CED relies on specific targeting and broad volume distributions (VD). However, to prevent off-target delivery and tissue damage, CED is typically conducted with small cannulas and at low flow rates, which critically limit the maximum achievable VD. Furthermore, in applications such as gene therapy requiring injections of large fluid volumes into broad subcortical regions, low flow rates translate into long infusion times and multiple surgical trajectories. The cannula design is a major limiting factor in achieving broad VD, while minimizing infusion time and backflow. Here we present and validate a novel multi-point cannula specifically designed to optimize distribution and delivery time in MR-guided intracranial CED of gene-based therapeutics. First, we evaluated the compatibility of our cannula with MRI and common viral vectors for gene therapy. Then, we conducted CED tests in agarose brain phantoms and benchmarked the results against single-needle delivery. 3T MRI in brain phantoms revealed minimal susceptibility-induced artifacts, comparable to the device dimensions. Benchtop CED of adeno-associated virus demonstrated no viral loss or inactivation. CED in agarose brain phantoms at 3, 6, and 9 μL/min showed &gt;3x increase in volume distribution and 60% time reduction compared to single-needle delivery. This study confirms the validity of a multi-point delivery approach for improving infusate distribution at clinically-compatible timescales and supports the feasibility of our novel cannula design for advancing safety and efficacy of MR-guided CED to the central nervous system.

scholarly journals Non-equilibrium model for solute transport in differently designed biofilters targeting agricultural drainage water

2017 ◽  
Vol 76 (6) ◽  
pp. 1324-1331 ◽  
Author(s):  
Lorenzo Pugliese ◽  
Jacob Bruun ◽  
Charlotte Kjaergaard ◽  
Carl Christian Hoffmann ◽  
Guenter Langergraber
Keyword(s):  
Flow Direction ◽  
Tracer Tests ◽  
Drainage Water ◽  
Degree Of Saturation ◽  
Model Parameters ◽  
Liquid Phase Mass Transfer ◽  
Flow Rates ◽  
Hydraulic Design ◽  
Longitudinal Dispersivity ◽  
Transport Behaviour

Biogeochemical processes in subsurface flow constructed wetlands are influenced by flow direction, degree of saturation and influent loading position. This study presents a simulation tool, which aims to predict the performance of the unit and improve the design. The model was developed using the HYDRUS program, calibrated and verified on previously measured bromide (Br−) pulse tracer tests. Three different hydraulic designs (Horizontal (HF), Vertical upward (VF-up), Vertical downward (VF-down) and two different flow rates: Low (L), and High (H)) were investigated. The model simulated well the Br− transport behaviour and the results underline the importance of the hydraulic design. Calibrated model parameters (longitudinal dispersivity, immobile liquid phase, mass transfer coefficient) showed a common trend for all the designs, for increasing flow rates within the investigated range. The VF-down performed best, i.e. had the highest hydraulic retention time.

A machine learning approach for the automatic long-term structural health monitoring

2018 ◽  
Vol 18 (3) ◽  
pp. 819-837 ◽  
Author(s):  
Giacomo Vincenzo Demarie ◽  
Donato Sabia
Keyword(s):  
Machine Learning ◽  
Data Acquisition ◽  
Structural Behavior ◽  
Practical Applications ◽  
Existing Structures ◽  
Machine Learning Approach ◽  
Modes Of Vibration ◽  
Engineering Parameters ◽  
Over Time

Measuring the response of a structure to the ambient and service loads is a source of information that can be used to estimate some important engineering parameters or, to a certain extent, to characterize the structural behavior as a whole. By repeating the data acquisition over a period of time, it is possible to check for variations in the structure’s response, which may be correlated to the appearance or growth of a damage (e.g. following some exceptional event as the earthquake, or as a consequence of materials and components aging). The complexity of some existing structures and their environment very often requires the execution of a monitoring plan in order to support analyses and decisions through the evidence of measured data. If the monitoring is implemented through a sensor network continuously acquiring over time, then the evolution of the structural behavior may be tracked continuously as well. Such approach has become a viable option for practical applications since the last decade, as a consequence of the progress in the data acquisition and storage systems. However, proper methods and algorithms are needed for managing the large amount of data and the extraction of valuable knowledge from it. This article presents a methodology aimed at making automatic the process of structural monitoring in case it is carried continuously over time. It relies on some existing methods from the machine learning and data mining fields, which are casted into a process targeted to delimit the need of the human being intervention to the training phase and the engineering judgment of the results. The methodology has been successfully applied to the real-world case of an ancient masonry bell tower, the Ghirlandina Tower (Modena, Italy), where a network made of 12 accelerometers and 3 thermocouples has been acquiring continuously since August 2012. The structural characterization is performed by identifying the first modes of vibration, whose evolution over time has been tracked.

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