VISUM-VISSIM

Now a day's traffic congestion issues in Chittagong city is becoming worse day by day. This happens due to the slow-moving vehicles, occupied footpath, unauthorized car and bus/truck lay over, traditional traffic signal timings Government authorities are building flyovers to abate the intensity of congestion which is not always a great solution but cost a huge amount of money. Saturation flow in any intersection is huge to control with traditional traffic signal system. The aim of this paper is to assess and develop the traffic operations at the AK Khan (T) and Alongkar (four leg) intersection which are situate near the most congested portion of Chittagong city due to bus terminal area. Traffic count studies are conducted to determine the number, movement and classification of vehicles at an intersection. In this study, an improved traffic signal timings i.e. green time, amber time and red time have selected for continuous movement of vehicles through the intersection to ameliorate the situation of delays, average speed and queue length to do that videography survey has conducted at 15 minutes of intervals during estimated peak hour. In addition, geometric, traffic and signalized data were collected during peak time periods. In this study, we calculated the signal timings (Green time, Yellow time, Red time, Cycle time and Lost time) and it is optimized by VISSIM which is a traffic simulation software. Delay time and average speed are determined manually and compared after optimization in VISSIM. Another alternative solution is given i.e. construction of one through overpass for one direction (from AK Khan to Alongkar) for through vehicles to have more improved traffic condition. These solutions will be advantageous for the signalized intersections especially during rush hours, decreasing the travel cost, greenhouse gas emission & number of accidents, increasing the efficiency of the road network, improving traffic flow and traffic operations.

The New Mexico Statewide Travel Demand Model (NMSTDM) has served a number of purposes since its initial development, providing support for projects around the state such as traffic projections for engineering design projects and Intermodal/Inland Port Facilities, and scenario testing project analysis for New Mexico Department of Transportation (NMDOT) Districts. The statewide model matters. A national research group forecasts that in 2017, $109 billion in goods will have been shipped to and from New Mexico, predominantly by trucks
(TRIP - A National Transportation Research Group, 2017). The average driver in the Albuquerque area loses 36 hours per year, and the Santa Fe driver about 19 hours due to congestion. New Mexico’s population reached 2.1 million in 2015, which is a 15% increase since 2000. Vehicle Miles Traveled (VMT) has increased by 16% from 2000 to 2015. For the same period, New Mexico’s gross domestic product increased by 24%, compared to 27% for the US. We expect New Mexico VMT will increase by 20% by 2030 (TRIP - A National Transportation Research Group, 2017). If the NMSTDM is to continue to serve the state’s needs and be able to provide support for planned infrastructure projects, the model must be updated, expanded and enhanced.  This report addresses the way we should improve the NMSTDM.
Consultants have supported modeling development and operations at NMDOT since 2008, but most recent support has been by one individual. So it is time to evaluate the state model and its platform. This report evaluates the current model and recommends improvements.
This report reviews national practices for State DOT travel demand models, different modeling platforms, various data sources available, the most common modeling concepts, and evaluates the NMSTDM. It concludes with specific recommendations on how the NMSTDM should be improved.

Advanced Driver Assistance Systems (ADAS) offer the possibility of helping drivers to fulfill their driving tasks. Automated vehicles are capable of communicating with surrounding vehicles (V2V) and infrastructure (V2I) in order to collect and provide essential information about driving environment.
Studies have proved that automated vehicles have a potential to decrease traffic congestion on road networks by reducing the time headway, enhancing the traffic capacity and improving the safety margins in car following. Furthermore, vehicle movement and driver’s behavior of conventional vehicles will be affected by the presence of automated vehicles in traffic networks. Despite different encouraging factors, automated driving raises some concerns such as possible loss of situation awareness, overreliance on automation and degrading driving skills in absence of practice. Moreover, coping with complex scenarios, such as merging at ramps and overtaking, in terms of interaction between automated vehicles and conventional vehicles need more research.
This thesis work aims to investigate the effects of automated vehicles on driver’s behavior and traffic performance. A broad literature review in the area of driving simulators and psychological studies was performed to examine the automated vehicle effects on driver’s behavior. Findings from the literature survey, which has been served as setup values in the simulation study of the current work, reveal that the conventional vehicles, which are driving close to the platoon of automated vehicles with short time headway, tend to reduce their time headway and spend more time under their critical time headway. Additionally, driving highly automated vehicles is tedious in a long run, reduce situation awareness and can intensify driver drowsiness, exclusively in light traffic. In order to investigate the influences of automated vehicles on traffic performance, a microscopic simulation case study consisting of different penetration rates of automated vehicles (0, 50 and 100 percentages) was conducted in VISSIM software. The scenario network is a three-lane autobahn segment of 2.9 kilometers including an off-ramp, on-ramp and a roundabout with some surrounding urban roads.
Outputs of the microscopic simulation in this study reveal that the positive effects of automated vehicles on roads are especially highlighted when the network is crowded (e.g. peak hours). This can definitely count as a constructive point for the future of road networks with higher demands. In details, average density of autobahn segment remarkably decreased by 8.09% during p.m. peak hours in scenario with automated vehicles. Besides, Smoother traffic flow with less queue in the weaving segment was observed. Result of the scenario with 50% share of automated vehicles moreover shows a feasible interaction between conventional vehicles and automated vehicles. Meaningful outputs of this case study, based on the input data from literature review, demonstrate the capability of VISSIM software to simulate the presence of automated vehicles in great extent, not only as an automated vehicle scenario but also a share of them, in traffic network. The validity of the output values nonetheless needs future research work on urban and rural roads with different traffic conditions.

Celem pracy jest wskazanie najkorzystniejszego z punktu widzenia przyjętych kryteriów, układu linii tramwajowych, które w rezultacie będą rekomendowane do obsługi nowej trasy tramwajowej na tzw. „Klin Dębiecki” w Poznaniu. W ramach rozważań nad tą tematyką, autor pracy w pierwszej kolejności szczegółowo przeanalizował lokalne uwarunkowania planistyczne i transportowe. Następnie zaproponował własną metodykę prowadzenia badań, w ramach której została wykonana analiza wielokryterialna uwzględniająca aspekty techniczne, ekonomiczne i jakościowe. Ocenie zostało poddanych kilka wariantów, różniących się przebiegami linii tramwajowych. Przy określaniu części miar cząstkowych, wykorzystano wyniki własnych badań symulacyjnych wykonanych w programie do modelowania ruchu i podróży VISUM.
W celu ostatecznego wyboru wariantu rekomendowanego do przyszłego wdrożenia, autor zastosował metodę wspomagania decyzji AHP (Analytic Hierarchy Process) tworząc w ten sposób ranking szeregujący zaproponowane układy linii tramwajowych od najlepszego do najgorszego względem przyjętych kryteriów.

Microscopic traffic simulation models are considered to be valuable and powerful tools for analyzing traffic operations in a wide range of planning and modeling tasks. However, modeling large-scale urban traffic networks is particularly challenging task even on a macroscopic level.
The challenges are multifold when attempting to represent large urban networks in high-fidelity manner with operational details. While many previous studies proposed various simulation model calibration and validation methods, these processes are still considered to be more an art than science, especially if performed manually. This study describes such a manually-crafted simulation building, calibration and validation process that features a major urban grid network, encompassed with 6 busy arterials and 160 signalized intersections. A VISSIM model was calibrated and validated by using variety of traffic data, from two temporally, spatially, and characteristically different field data-collection campaigns. The accuracy and sensitivity of the model was repetitively fine-tuned and tested, until a chosen calibration criteria for several variables (volume, speed and travel times) was successfully met. Validation tests were performed with a completely fresh dataset at the end of the process. While the calibration efforts were a full success, the validation results were only half successful. Potential factors that could have impacted the mixed validation results are higher sensitivity of the validation data and seasonal shifts in traffic demand and distribution. Future research will focus on collecting and testing new validation data sets, which will improve robustness and reliability of the simulation model.

Highway Capacity Manual (HCM) 2010 methodology for freeway operations contain procedures for calculating traffic  performance measures both for undersaturated and oversaturated flow conditions. However, one of the limitations regarding oversaturated freeway weaving segments is that the HCM procedures have not been extensively calibrated based on field observations on U.S. freeways. This study validates
the HCM2010 methodology for oversaturated freeway weaving segment by comparing space mean speed and density obtained from HCM procedure to those generated by a microsimulation model. A VISSIM model is extensively calibrated and validated based on NGSIM field data for the US 101 Highway. Abundance of the NGSIM data is utilized to calibrate and validate the VISSIM model. Results show that HCM methodology has
significant limitations and while in some cases it can reproduce density correctly, the study finds that speeds estimated by the HCM methodology significantly differ from those observed in the field.

Deterioration of freeway traffic flow condition due to bottlenecks can be ameliorated with ramp metering.  A challenge in ramp metering is that it is not possible to process data in real-time and use the output in a control algorithm.  This is due to the fact that by the time processing is completed and a control measure applied, the traffic state will have changed. A solution to this problem is to forecast the traffic state and implement a control measure based on the forecast.  A dual-state Kalman filter was used to forecast traffic data at two locations on a freeway (I-84).  A Kalman filter is an optimal recursive data processing algorithm; predictions are based on only the previous time-step’s prediction and all previous data do not need to be stored and reprocessed with new measurements.  A coordinated feedback ramp metering control logic was implemented. The closed-loop system seeks to control the traffic density on the mainline while minimizing on-ramp queues through weighting functions.  The integration of the Kalman filter with the ramp meter control logic accomplishes the ramp meter algorithmic scheme in which is proactive to changes in freeway conditions by controlling a forecasted state.  In this closed-loop framework, real-time forecasts are produced with a continuously updated prediction that minimizes errors and recursively improves with each successive measurement. MATLAB was used to model the closed-loop control system as well as modify the input output constraints to evaluate and tune controller performance.

Several factors are usually considered when recommending left-turn phasing at signalized intersections: the volume of through traffic opposing the left-turn maneuvers, the volume of left-turn traffic, the speed of the opposing traffic, sight distance, crash history, and cycle length. The goal of this paper is to find the optimal signal phasing designs that can improve efficiency and safety of the particular signal design in the field in order to test current recommendations and guidelines on left-turn treatments. The researchers assess the impact of the number of rings in a phasing structure, the number of phases and whether to adopt lead or lag phasing on the safety and efficiency of a four-legged signalized intersection. A comprehensive set of 338 signal phasing designs is developed and the impacts are modeled using VISSIM microsimulation. The efficiency of signal phasing sets is evaluated in VISSIM, while the safety aspect is assessed using SSAM software. Optimal scenarios are tested using sensitivity analysis for various traffic flows. The findings show that the current left-turn guidelines may over-protect left-turners which results in reduced efficiency and left-turn delays that can be increased by up to 25%. Revised guidelines should contribute to the decreased delays for left turning vehicles, while keeping the safety standards high.

Vissim is a microscopic road traffic simulator based on the individual behavior of vehicles. The  goal  of  the  microscopic  modeling  approach  is  the  accurate  description  of  the  traffic dynamics. Thus, the simulated traffic network may be analyzed in detail. The simulator uses the  so-called  psycho-physical  driver  behavior  model  developed  originally  by  Wiedemann (1974). Vissim is widely used for diverse problems by traffic engineers in practice as well as by researchers for developments related to road traffic.Vissim offers a user friendly graphical interface (GUI) through of which one can design the geometry of any type of road networks and  set  up  simulations  in  a  simple  way.  However,  for  several  problems  the  GUI  is  not satisfying. This is the case, for example, when the user aims to access and manipulate Vissim objects  during  the  simulation  dynamically.  For  this end,  an  additional  interface  is  offered based  on  the  COM which  is  a  technology  to  enable  interprocess  communication  between software (Box, 1998). The Vissim COM interface defines a hierarchical model in which the functions and parameters of the simulator originally provided by the GUI can be manipulated by programming.  It  can  be  programmed  in  any  type  of  languages which  is  able  to  handle COM objects (e.g. C++,Visual Basic,Java, etc.). Through Vissim COM the user is able to manipulate the attributes of most of the internal objects dynamically.

Traffic microsimulation is an essential tool in urban transportation and road planning. Its calibration is essential to attain representative results validated with real-world conditions. VISSIM (Verkehr in Städten-SIMulationsmodell) operates with the Wiedemann's psycho-physical car-following model for freeway travel that considers safety distances (standstill and movement) during simulation. Calibration in this paper was achieved by using two different approaches: a) manual and b) genetic algorithm (with the GEH statistic formula) calibration techniques. Calibration and validation of this model were performed at the Periferico de la Juventud expressway in Chihuahua City, in northern Mexico. The Periferico de la Juventud (PDJ) has a N-S orientation and a length of ca. 20 km, with its northern section being its most congested portion. Its highest vehicle volume occurs at noon, with 3700 vehicles per hour, with 95% being passenger cars and the other 5% heavy goods vehicles. PDJ's speed limit is 70 km•h −1 , but the driver's behavior has a tendency towards the aggressive performance. A total of 82 standstill and 82 look-ahead distances were obtained from unmanned aerial vehicles (UAV) images, with values ranging from 0.8 to 4.7 m and from 0.2 to 28 m, respectively. VISSIM calibrated parameter values were calculated for this expressway, being slightly above than the VISSIM default ones; and was validated with travel times and look-ahead distances. Results contribute information for the city's future installment of public transportation systems, and should help decision makers deal with future urban planning.

In the Middle East, large scale, car-orientated, suburban developments are being built, sometimes on private estates, sometimes on public land. Driver experience, however, is usually not considered during the design process, leading to potential complaints from new residents. Can drivers’  communting experience be taken into account at concept design stage?

Ada County, Idaho is the financial and population center of the Boise Metropolitan Area, which is expected to experience population growth from 600,000 in 2013 to over 1,000,000 by 2040. Planning for such growth is essential and with that, the need arises for sophisticated transport models to assist as effective aids in decision-making. To meet these needs, a 3-Step model, which includes trip generation, trip distribution, and a capacity constrained equilibrium traffic assignment process, using the Visum transportation planning software package, was developed for Ada County, Idaho.

The HCM2010 freeway facilities methodology offers a supplemental computational engine FREEVAL, which is a macroscopic/mesoscopic tool. It enables users to implement HCM-based freeway analysis quickly. Vissim is a microscopic simulation tool that enables users to model real-world conditions with high level of accuracy. One of the commonly used performance measures for freeway assessment is the Level-of-Service (LOS). The HCM freeway facility methodology uses density to estimate LOS. However, density is calculated differently in FREEVAL and Vissim, and comparing the estimated LOSs between the two may lead to invalid conclusions. The aim of this paper is to address a gap in the literature by comparing and contrasting the methodologies behind the two tools and by offering explanation and discussion of their outputs in terms of density and LOS. The study covers three major HCM freeway segment types (basic, on-ramp, and weaving) in under-saturated conditions. The assessment reveals that both tools are capable of replicating the field conditions after the calibration process. Finding show that LOS differs by maximum one grade between these tools. Segment density obtained from HCM methods is generally higher than the segment density from Vissim microsimulation.

Users of International Land Ports of Entries (LPOEs) at the US – Mexico border experience excessive wait times on a daily basis. This contributes to the increased transportation costs, and also generates health and environmental problems in border regions. Traffic simulation models are effective tools for evaluating passenger vehicle, pedestrian and commercial traffic operations. These tools can be used to assess various scenarios and visualize current traffic conditions. Results obtained from these tools should be taken into account in congestion relief decision making processes. The research team developed, calibrated and validated three traffic models of the Ysleta-Zaragoza LPOE using three different software packages (i.e., Transmodeler, VISSIM, and Aimsun). This paper presents advantages and disadvantages of each tool when modeling international LPOEs. Results presented herein can be used by practitioners to decide which tool should to be used for modeling LPOEs at the U.S. – M...

Hiện nay, tình trạng ngập úng do mưa lũ tại các thành phố lớn ở Việt Nam, nhất là các khu chung cư, khu đô thị (đặc biệt là những tòa nhà có tầng hầm), ngày càng diễn ra phức tạp và để lại những thiệt hại nghiêm trọng về tài sản, cũng như bức xúc trong cư dân. Để giải quyết vấn đề này, công ty CIC xin trân trọng giới thiệu tới Quý công ty giải pháp Đê mềm chống ngập “Water Barrier” của hãng AET Flood Defence Limited (Anh Quốc), giúp ngăn chặn dòng nước lũ xâm nhập vào bên trong tòa nhà, đặc biệt là các tầng hầm.

ỨNG DỤNG
- Chống ngập tầng hầm các trung tâm thương mại, chung cư...
- Bảo vệ toàn diện các căn nhà nằm trong vùng ngập lụt.
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NGUYÊN TẮC HOẠT ĐỘNG RẤT ĐƠN GIẢN

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Link chi tiết sản phẩm: https://cic.com.vn/san-pham/de-mem-chong-ngap-ngan-lu-hang-aet-anh-quoc?fbclid=IwAR1ToKR7YRVAzCi-zjV5GG0f2zLxI_9kTDe-1hltk9s7GR5uVNpXewyAguk