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Articles 1 - 17 of 17
Full-Text Articles in Engineering
Safety Impacts Of Signal-Warning Flashers And Speed Control At High-Speed Signalized Intersections, Zifeng Wu, Anuj Sharma, Fred L. Mannering, Shefang Wang
Safety Impacts Of Signal-Warning Flashers And Speed Control At High-Speed Signalized Intersections, Zifeng Wu, Anuj Sharma, Fred L. Mannering, Shefang Wang
Anuj Sharma
For many years, to reduce the crash frequency and severity at high-speed signalized intersections, warning flashers have been used to alert drivers of potential traffic-signal changes. Recently, more aggressive countermeasures at such intersections include a speed-limit reduction in addition to warning flashers. While such speed-control strategies have the potential to further improve the crash-mitigation effectiveness of warning flashers, a rigorous statistical analysis of crash data from such intersections has not been undertaken to date. This paper uses 10-year crash data from 28 intersections in Nebraska (all with intersection approaches having signal-warning flashers; some with no speed-limit reduction, and the others …
Recasting Dilemma Zone Design As A Marginal Cost-Benefit Problem, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Recasting Dilemma Zone Design As A Marginal Cost-Benefit Problem, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Anuj Sharma
One control objective at high-speed isolated intersections is to provide safe phase transition by minimizing the occurrence of high-speed vehicles in the dilemma zone before the phase is terminated. An upper limit for extending the green (maximum green time) is used to avoid an indefinite extension of the main-street green. Currently, the maximum green times are chosen by using engineering judgment. This approach does not explicitly consider the trade-offs between safety and delay and hence often results in both unsafe and inefficient performance at the intersection under medium to heavy traffic volumes. The dilemma problem is recast as one of …
Effect Of Phase Countdown Timers On Queue Discharge Characteristics Under Heterogeneous Traffic Conditions, Anuj Sharma
Effect Of Phase Countdown Timers On Queue Discharge Characteristics Under Heterogeneous Traffic Conditions, Anuj Sharma
Anuj Sharma
Analysis of queue discharge characteristics at signalized intersections is a primary component of traffic signal analysis and design. On the basis of previous studies, mainly conducted in homogeneous traffic conditions, the discharge headway is assumed to be high at the start of green for the first few vehicles, mainly because of start-up lost times, and is also assumed to reach the minimum value by the fourth or fifth vehicle in the queue. The minimum headway is expected to continue until the end of the queue. However, this may not be the case under heterogeneous traffic conditions, such as those in …
Determination Of Traffic Responsive Plan Selection Factors And Thresholds Using Artificial Neural Networks, Anuj Sharma
Determination Of Traffic Responsive Plan Selection Factors And Thresholds Using Artificial Neural Networks, Anuj Sharma
Anuj Sharma
Traffic congestion has become a menace to civilized society. It degrades air quality, jeopardizes safety and causes delay. Traffic congestion can be alleviated by providing an effective traffic control signal system. Closed-loop traffic control systems are an example of such a system. Closed-loop traffic control systems can be operated primarily in either of two modes: Time of Day Mode (TOD) or Traffic Responsive Plan Selection Mode (TRPS). TRPS mode, if properly configured, can easily handle time independent variation in traffic volumes. It can also reduce the effect of timing plan aging. Despite these advantages, TRPS mode is not used as …
Event-Based Data Collection For Generating Actuated Controller Performance Measures, Edward J. Smaglik, Anuj Sharma, Darcy M. Bullock, James R. Sturdevant, Gary Duncan
Event-Based Data Collection For Generating Actuated Controller Performance Measures, Edward J. Smaglik, Anuj Sharma, Darcy M. Bullock, James R. Sturdevant, Gary Duncan
Anuj Sharma
Cycle-by-cycle data have been shown to be effective in the analysis of a signalized intersection with measures of effectiveness such as volume-to-capacity ratios, arrival type, and average vehicular delay. Currently, actuated traffic controllers are unable to store vehicle counts and vehicle occupancy in cycle-by-cycle bins, requiring extra equipment and personnel to collect data in these bins. The objective of this research was to develop an integrated general purpose data collection module that time stamps detector and phase state changes within a National Electrical Manufacturers Association actuated traffic signal controller and uses those data to provide quantitative graphs to assess arterial …
Multiobjective Plan Selection Optimization For Traffic Responsive Control, Montasir M. Abbas, Anuj Sharma
Multiobjective Plan Selection Optimization For Traffic Responsive Control, Montasir M. Abbas, Anuj Sharma
Anuj Sharma
Optimal coordination of traffic signals requires proper activation of timing plans to match current traffic conditions. One of the greatest challenges in configuring a traffic responsive plan selection control mode is how to select only n number of timing plans (restricted by traffic controller memory limitations) to address possibly all traffic conditions/states that can be encountered in the field, for a specific site, but most importantly, how to associate each of these traffic conditions to one of the n timing plans stored in the traffic controller. This paper uses a multiobjective non-dominated sorting genetic algorithm to (1) select the best …
Stochastic Algorithm For Improved Operations At Isolated High Speed Intersections, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Stochastic Algorithm For Improved Operations At Isolated High Speed Intersections, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Anuj Sharma
The current practice of specifying simultaneous gap out logic at isolated high speed signalized intersections places constraints on the signal controller logic that cannot be satisfied under high congestion level. Further, it often results in degraded signal efficiency and dilemma zone protection. A stochastic approach is proposed in this paper with the objective of increasing safety and efficiency at these intersections.
Detection Of Inclement Weather Conditions At A Signalized Intersection Using A Video Image Processing Algorithm, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta, James V. Krogmeier
Detection Of Inclement Weather Conditions At A Signalized Intersection Using A Video Image Processing Algorithm, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta, James V. Krogmeier
Anuj Sharma
Inclement weather conditions like snowfall adversely affect traffic flow characteristics, necessitating a change in parameters that define the operation of a signalized intersection. A weather-based timing plan selection is needed to maintain a desirable level of operational efficiency. Automatic implementation of weather-based timing at intersections requires accurate and timely detection of snowfall. This paper presents a snow detection algorithm that uses live video feed obtained from a video image vehicle detection system present at an intersection.
Configuration Methodology For Traffic-Responsive Plan Selection: A Global Perspective, Montasir M. Abbas, Nadeem A. Chaudhary, Geza Pesti, Anuj Sharma
Configuration Methodology For Traffic-Responsive Plan Selection: A Global Perspective, Montasir M. Abbas, Nadeem A. Chaudhary, Geza Pesti, Anuj Sharma
Anuj Sharma
Although several studies have shown the potential great benefits of traffic-responsive plan selection (TRPS) control, time-of-day operation continues to be the primary method used to select patterns for signal control applications. This practice could be largely attributed to the minimal guidelines available on the setup of the TRPS mode. An innovative framework for TRPS system setup is provided, and guidelines for implementing TRPS in a simplified manner are shown. The guidelines, developed at Texas Transportation Institute (TTI), use a comprehensive approach that incorporates a multiobjective evolutionary algorithm and a supervised discriminant analysis. Engineers can directly implement the guidelines presented as …
Limitations Of Simultaneous Gap-Out Logic, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Limitations Of Simultaneous Gap-Out Logic, Anuj Sharma, Darcy M. Bullock, Srinivas Peeta
Anuj Sharma
The current practice of specifying simultaneous gap-out logic places constraints on signal controller logic. These constraints cannot be achieved under high traffic flow conditions, and degraded signal efficiency and dilemma zone protection often result. This study documents the phenomenon described above with set-back detectors at an instrumented intersection in Noblesville, Indiana, and characterizes the problem of dilemma zone protection as being traffic-volume dependent, a factor that should be carefully considered before the simultaneous gap-out logic is applied. Implementation of simultaneous gap-out logic led to max out ranging from 3.5% to 40% of cycles per hour during peak traffic flow periods …
Input-Output And Hybrid Techniques For Real-Time Prediction Of Delay And Maximum Queue Length At Signalized Intersections, Anuj Sharma, Darcy M. Bullock, James A. Bonneson
Input-Output And Hybrid Techniques For Real-Time Prediction Of Delay And Maximum Queue Length At Signalized Intersections, Anuj Sharma, Darcy M. Bullock, James A. Bonneson
Anuj Sharma
Vehicle delay and queue length are quantitative measures of intersection performance. The technological advancement in the field of vehicle sensors and traffic controllers has reached a point where it has enabled efficient measurement of these performance measures. Two techniques are presented for real-time measurement of vehicle delay and queue length at a signalized Intersection, and these automated delay and queue estimates are compared with manually ground-truthed measurement. These techniques were evaluated at an instrumented intersection in Noblesville, Indiana. The root-mean-square error by both techniques was below 0.7 veh-s for-estimation of average delay and less than 0.15 vehicle for estimation of …
Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma
Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma
Anuj Sharma
This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …
Pilot Study On Real-Time Calculation Of Arrival Type For Assessment Of Arterial Performance, Edward J. Smaglik, Darcy M. Bullock, Anuj Sharma
Pilot Study On Real-Time Calculation Of Arrival Type For Assessment Of Arterial Performance, Edward J. Smaglik, Darcy M. Bullock, Anuj Sharma
Anuj Sharma
The Highway Capacity Manual uses the arrival type (AT) as a mechanism to account for the quality of traffic signal coordination in the calculation of delay at a signalized intersection. Although there is much discussion in the literature regarding the accuracy and precision of this approach, the AT parameter provides a simple mechanism for grading the performance of traffic signal coordination. This paper describes data collection limitations of current traffic signal controllers and proposes a procedure where the AT parameter can be calculated by traffic signal controllers in real time. Given that the nation received a score of 61 out …
Optimization Of Time Of Day Plan Scheduling Using A Multi-Objective Evolutionary Algorithm, Montasir M. Abbas, Anuj Sharma
Optimization Of Time Of Day Plan Scheduling Using A Multi-Objective Evolutionary Algorithm, Montasir M. Abbas, Anuj Sharma
Anuj Sharma
Coordinating traffic signals can provide great savings to motorists in terms of reduced delays and number of vehicular stops. In order to maximize benefits, engineers need to use a mechanism by which the most optimal timing plans are activated when the traffic patterns change. Common ways of accomplishing this need is by using Time of Day (TOD) plan scheduling, or Traffic Responsive Plan Selection (TRPS). Out of the two modes, the TOD mode is by far the most common. Engineers, however, typically use their judgment to determine the TOD plan scheduling. Unless traffic patterns change at certain times of the …
Performance Requirements And Evaluation Procedures For Advance Wide Area Detectors, Anuj Sharma, Matthew Harding, Brad Giles, Darcy M. Bullock, James R. Sturdevant, Srinivas Peeta
Performance Requirements And Evaluation Procedures For Advance Wide Area Detectors, Anuj Sharma, Matthew Harding, Brad Giles, Darcy M. Bullock, James R. Sturdevant, Srinivas Peeta
Anuj Sharma
Dilemma zone protection ideally requires the exact position and speed of all the vehicles approaching the intersection. However, point detectors, typically used to protect vehicle incursion into the dilemma zone, only provide binary information about the presence or absence of a vehicle at a fixed point in space. The information regarding position and speed of the vehicle in subsequent time steps is extrapolated. The extrapolation error increases with the increase in projection time. Wide area detector (WAD) overcomes this drawback by tracking each vehicle at all times until they move out of range. Such a detector has the potential to …
Configuration Of Traffic-Responsive Plan Selection System Parameters And Thresholds: Robust Bayesian Approach, Montasir M. Abbas, Anuj Sharma
Configuration Of Traffic-Responsive Plan Selection System Parameters And Thresholds: Robust Bayesian Approach, Montasir M. Abbas, Anuj Sharma
Anuj Sharma
Traffic-responsive plan selection (TRPS) is one of the two major closed-loop system modes of operation. The TRPS mode is more beneficial than its competitor (time-of-day mode) because of its ability to accommodate abnormal traffic conditions such as incidents, special events, and holiday traffic. However, no guidelines are available for optimal setup of TRPS systems. Improper configuration of a TRPS system can result in inefficient system performance or unstable operation in which the closed-loop system operates in a perpetual transitioning state. The TRPS mechanism implemented in current traffic signal controllers is described, and a Bayesian-based methodology for selecting an optimal set …
Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma
Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma
Anuj Sharma
Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …