Delay Time Model at Unsignalized Intersections (original) (raw)
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Minor Road Traffic Delays at Priority Junctions on Low Speed Roads in Suburban Areas
Jurnal Teknologi, 2014
Traffic delay is one of the important aspects considered in the assessment of the operational performance of intersections. In the analysis of priority or unsignalised junctions, delays to minor road vehicles are often estimated using the existing mathematical models. However, the applicability of such a model depends on the basis and the source of the data with which the model was calibrated. This study was carried out to evaluate traffic delays to minor road vehicles at priority junctions in suburban areas. The data were collected at two priority junctions using video recording technique. The results showed that the day time delays were longer than of those observed during the twilight time. In both situations, delay to minor road vehicles increases as the volume of major road traffic increases. However, the effect of conflicting volume on the delay to the minor road vehicles is not clear. The comparisons between observed delay and the values predicted using the HCM and Tanner’s m...
Sohag Engineering Journal (Print), 2022
Macroscopic traffic analysis software (SIDRA) and microscopic simulation package (VISSIM) are used in this paper to get the theoretical delay time. The paper presents a calibration process for the models developed in Sohag government using VISSIM software, since microscopic simulation models are becoming increasingly important tools in modeling transport systems. Traffic simulation models sometimes provide significant advantages over traditional planning or analytical models, such as SIDRA. Other common reasons for the popularity of simulation models include their attractive animations; their stochastic variability for the capture of real-world traffic conditions; and their capabilities to model complex roadway geometries, such as combined systems of urban streets and freeways. After calibration, validation work using field data from a signalized intersection in Sohag Governorate, Egypt, was conducted and proved the model validity to represent real systems. The simulation model was applied to evaluate the impact of lane width and traffic volume parameters on vehicular delays. The impact of each parameter was assessed and analyzed. It was found that there is a direct proportion between the control delay and the traffic volume parameter and inversely with the lane width parameter. Additionally, the problem of traffic jam at any intersection begins to occur when the traffic volume at 900 veh /h and above at different lane widths, especially at 9 ft resulting in higher delays.
Investigation of Cyclic Vehicle Queue and Delay Relationship for Isolated Signalized Intersections
Delay is the one of the design criteria that has been used for performance evaluation of signalized intersections. In pre-timed control, vehicle delays can be minimized or reduced by proper design of signal timings and phasing. But vehicle delays include many parameters such as signal timing, number of phases, vehicle headways, saturation flow, queueing etc. Among these parameters vehicle queue is formed by unbalanced signal timings or unexpected demand values. On the other hand, headways of vehicles can be effective on queue forming especially in discharging case. It is also related to driver behaviors. In this paper, relationship of cyclic vehicle queue and vehicular delay is investigated considering different signal timings and phase sequencing. The data are obtained from observations that are made at urban intersections of Denizli city, Turkey. Regression analysis is used for relationship and statistical tests are applied. The MuLReD (Multiple Linear Regression Analysis based Delay Estimation) model is developed and significance of the model is proved by statistically. Adjusted R2 value of MuLReD Model is obtained as 0,95. On the other hand, delay values obtained from the MuLReD Model and Akcelik Vehicle Delay Formula are compared with each other. As a result of comparisons, Mean Square Error (MSE) values for Akcelik Equation and the MuLReD Model are determined as about 112 and 7 respectively. These results show that outcomes obtained by the MuLReD Model are closer to field observations. Discussions about the present delay formulas, are also reported in the paper.
Generalized Delay Model for Signalized Intersections and Arterial Streets
Transportation Research Record: Journal of the Transportation Research Board, 1997
Average delay per vehicle is the primary measure for determining the level of service at signalized intersections. This performance measure is also a major component in the calculation of average travel speed used to determine the level of service on arterial streets. The most widely used models for estimating delay at signalized intersections are those in Chapters 9 ("Signalized Intersections") and 11 ("Urban and Suburban Arterials") of the Highway Capacity Manual. This research reviewed the literature on models for estimating delay at signalized intersections to identify limitations and formulate revised models to address those limitations. Specific problems that were addressed included the inability to account for actuated-control parameters, oversaturation and variable demand, and metering and filtering by upstream traffic signals. The research team developed a generalized delay model to address these limitations and then validated the generalized model with ...
Estimation of delay at signalized intersections for mixed traffic conditions of a developing country
International Journal of Civil Engineering, 2013
Delay is one of the principal measures of performance used to determine the Level of Service (LOS) at signalized intersections and several methods have been widely used to estimate vehicular delay. Very few studies only have been carried out to estimate delay at signalized intersections under mixed traffic conditions prevailing in developing countries like India. In the present study, various problems associated with delay estimation under mixed traffic conditions in a developing country (India) and the methods to over come them were discussed and an attempt was made to improve the accuracy estimating the same. Five isolated signalized intersections from a fast developing industrial city located in TamilNadu, India were chosen for the study. Site specific PCU values were developed considering the static and dynamic characteristics of vehicles. Saturation flow was also directly measured in the field for the prevailing roadway, traffic and signalized conditions and expressed in PCU/h....
Impact of Road Users Behaviour on Intersection Performanceusing Vissim Micro-Simulation
The behaviour of motorist at the studied intersection constitute serious hazards as well as long queue and delay at intersection approaches especially during the peak periods, morning and evening. This study evaluated traffic performance at selected intersection, through the evaluation of intersections performance with reference to current traffic conditions in Ilorin city.Traffic data was collected at Maraba Intersection area in Ilorin city using Drone camera because it provides long lasting record of data with minimum manpower. Data were extracted through manual counting, and processed using EXCEL sheets.AVISSIM micro-simulation model was used to create a virtual environment representing the current traffic scenario.The study reveals that there are different Levels of Service (LOS) available on different approaches, the Post Office Road, Kulende Road and Sabo-oke Road records the critical LOS of D (Approaching unstable flow with tolerable delay) from all the turning movements, while the Amilegbe Road records the best LOS of B (Stable flow with slight delays).From the evaluation of the average approach delays obtained from the field study and VISSIM simulation model,it could be observed that the percentage difference between the field and model data is less than 10% which indicates that there are no significant differences.It is therefore appropriate to note that Maraba intersection operates at a very low level of service.Hence, there is need for government to make theexisting Automated Traffic Control signalling functionaland inscribe pavement markings on all the approaches lane to enhance the intersection performances.
Sulaymaniyah city is suffering from congestion, vehicle delays on most streets and intersections especially during peak hours, causing a lot of traffic problems and a negative impact on economy of the country. The increasing number of vehicles and limited new road construction will increase the problem in the network. The correct prediction of delay and queue length become important to make the most efficient use of the existing road system by providing better traffic operation and control. The objective of this study is the evaluation of traffic performance at selected network, through the evaluation of intersections performance and development of delay time and queue length models with reference to traffic prevailing conditions at Sulaymaniyah city. This is followed by suggestions of some improvement proposals including changing timing plan, geometric improvement and changing intersection type. To carry out the above objective, traffic data is collected at the network in CBD area in Sulaymaniyah city. Video camera is used to collect field data because it provides permanent record of data with minimum manpower. These data are abstracted from video records using EVENT program, and processed by prepared EXCEL sheets, while, the spot speed data for each entire link in the network are collected using pavement marking method. SYNCHRO/SIMTRAFFIC software V.20 is used for evaluation and analysis of intersections, best timing plan and coordination. Suggested proposals are evaluated for the target year 2017 by using mentioned software. Regression models, developed to estimate delay and queue length, show good correlation with field values. The ratio of total width of exit roadway of intersection for traffic departing straight forward to total width of lane groups departing to the same exit roadway at the same phase at stop line (We/Ws) appear to affect the delay. The ratio has a negative effect on delay time when the ratio is less than 1.0. Delay is estimated by HCM 2000 delay model and compared with field delay. Based on results obtained from analysis, HCM 2000 delay model has been modified to represent the field delay. It has been observed that, HCM 2000 delay model consistently over estimates delay at degree of saturation more than 1.0. It has been suggested from the analysis that, theoretical HCM 2000 delay model may be reduced by 81 % to better reflect field conditions. Recommended delay model shows good correlation with field data within the limits of this study. Improvement strategies applied to the traffic flow in the study area of Sulaymaniyah city, through the application of the calibrated software (SYNCHRO/ SimTraffic). The improvement strategies divides into two parts. The first part includes Signal Timing Optimization and Coordination. The second part includes the geometric improvement. This improvement has very good effect on the measure of effectiveness (MOE) for the study network. Finally, the measure of effectiveness obtained from SYNCHRO/ SimTraffic optimization runs after the last improvement strategy for the target year 2017
Traffic delay problems are manifesting in many of the major urban centres in Nigeria. The paper examined traffic delay problem and its causes at selected road intersections in Ilorin, Nigeria. The characteristics of the intersections that predispose them to delay problem and the spatial pattern of traffic delay at the road intersections were also identified. In addition, traffic volume and delay characteristics were estimated. Data were collected through direct field surveys on intersection characteristics, traffic volume, composition, delay causes and land use activities. The analysis of data collected revealed that variations exist in traffic flows and delays at the studied intersections. Also, traffic delays are discovered to be associated with the traffic volumes at the various junctions which ultimately translate to traffic congestion. Furthermore, traffic wardens and parking problems were found to be the greatest causes of delays at the road intersections in the city. The study therefore recommends that the road intersections be signalized and vehicle parking be strictly prohibited to reduce traffic congestion and delays at road intersections in the city.
Variations in Capacity and Delay Estimates from Microscopic Traffic Simulation Models
Transportation Research Record: Journal of the Transportation Research Board, 2002
One of the issues involved in using microscopic simulation models is the variation in the simulation results. This study examined some of the more popular microscopic traffic simulation models, CORSIM, SimTraffic, and VISSIM, and investigated the variations in the performance measures generated by these models. The study focused on the capacity and delay estimates at a signalized intersection. The effects of link length, speed, and vehicle headway generation distribution were also investigated. With regard to variations in performance measures, the study found that CORSIM yields the lowest variations, whereas SimTraffic yields the highest. The highest variation in each simulation model normally occurs when the traffic demand approaches capacity. It was also found that delays are affected by the link length and speed in simulation models. Such an impact on delays is closely related to the range of speed variations. In general, shorter links and higher link speeds result in lower dela...