Automatic System to Measure Turning Movement and Intersection Delay
Automatic System to Measure Turning Movement and Intersection Delay

Author: Jialei Mao

Publisher:

Published: 2009

Total Pages: 75

ISBN-13:

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"It is important for many traffic operations, such as real-time adaptive signal control, dynamic traffic assignment and traffic demand estimation, to obtain the vehicle turning movement information at a signalized intersection. However, it is laborious and time consuming to count the turning movements manually. Previous efforts on this problem relied on a mathematical approach by solving an O-D matrix in which the turning movements represent distributions of the arriving flow at each intersection approach. However, such a matrix cannot be mathematically solved without using supplementary volume data from the local detectors; previous studies showed the results from the O-D method are not accurate. Identifying vehicle turning movements from detector information is a more direct method. Limited studies using this method have been found for intersections without shared lanes. Most intersections allow shared lane operations, thus this method is not practical without further improvements. Driven by the need to identify vehicles turning movement automatically regardless of the geometry and operation of the intersections, this research studied and developed a system called Automatic Turning Movement Identification System (ATMIS). ATMIS utilizes intelligent detection matching algorithm to identify vehicle turning movements from the detections collected from the field in real-time. This algorithm has the capability to compensate the error caused by the faults detections and shared lanes. The results from laboratory experiments and field tests are very encouraging. Future work is also discussed in the thesis. While another related study, intersection delay measurement, is also included in this thesis. Delay is regarded as one of the most important Measures of Effectiveness (MOE) for signalized intersections. Different methods to measure control delay are recommended by many researchers but most of them are costly, time consuming and labor intensive. Some key components of delay measurement, such as intersection delay and delay for different turning movements, are not addressed in the previous studies. Driven by the need to develop an automatic delay estimation system, a method is presented to improve or extend the current methods to estimate intersection travel time based on the detection information derived from ATMIS. Yet, the detection information is not perfect from ATMIS, we still can estimate intersection delay accurately with the help of data filters. The mechanism and result of proposed method are discussed in this thesis. Further work of delay measurement is also presented."--Abstract.

Data Fusion Technique for Measuring Intersection Delay Using GPS-enabled Probe Vehicles
Data Fusion Technique for Measuring Intersection Delay Using GPS-enabled Probe Vehicles

Author: Byung-Hee Han

Publisher:

Published: 2007

Total Pages: 96

ISBN-13:

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Intersection control delay is considered a primary measure for determining the level of service at signalized intersections. This thesis develops a technique estimating intersection delay using GPS data from GPS-enabled vehicles. First, this study analyzes existing methods that estimate control delays using GPS data and proposes an improved technique in response to the weakness of those methods. The proposed method estimates the control delay well with better accuracy covering the weaknesses. However, the control delay from the GPS data has a sample size problem for determining the level of service at signalized intersections. Therefore, this thesis proposes a data fusion technique using the data from both GPS devices and loop detectors in order to be able to estimate delays and the level of service at signalized intersections with the small number of GPS-enabled vehicles. The data fusion technique developed in this study improves the accuracy by 59.6% with one GPS-enabled vehicle.

A Technique for Measurement of Delay at Intersections
A Technique for Measurement of Delay at Intersections

Author: W. R. Reilly

Publisher:

Published: 1976

Total Pages: 176

ISBN-13:

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Findings are presented relating to the design of a simple yet accurate technique for measurement of vehicular delay on the approach to a signalized intersection. Precise definitions were established for four measures of performance; stopped delay, time in queue delay, approach delay, and percent of vehicles stopping. Approach delay was selected as being the most representative of intersection efficiency. Four manual methods were tested in the laboratory using film taken at 10 intersections. The values thus obtained were statistically compared with true values from time-lapse photography. The point sample, stopped delay procedure, and the percent of vehicles stopping method were selected as the most promising methods for practical use and were performed in the field at three sites.

A Technique for Measurement of Delay at Intersections: Users manual
A Technique for Measurement of Delay at Intersections: Users manual

Author: W. R. Reilly

Publisher:

Published: 1976

Total Pages: 76

ISBN-13:

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Findings are presented relating to the design of a simple yet accurate technique for measurement of vehicular delay on the approach to a signalized intersection. Precise definitions were established for four measures of performance; stopped delay, time in queue delay, approach delay, and percent of vehicles stopping. Approach delay was selected as being the most representative of intersection efficiency. Four manual methods were tested in the laboratory using film taken at 10 intersections. The values thus obtained were statistically compared with true values from time-lapse photography. The point sample, stopped delay procedure, and the percent of vehicles stopping method were selected as the most promising methods for practical use and were performed in the field at three sites.

Assessing the Value of Model Calibration for Signalized Intersection
Assessing the Value of Model Calibration for Signalized Intersection

Author:

Publisher:

Published: 2004

Total Pages:

ISBN-13:

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The Highway Capacity Manual (HCM) provides the most widely used methodologies for evaluating the quality of service on highway and street facilities. However, many users contend that the HCM models they are using are not accurate in emulating some real world conditions. In this thesis, the HCM control delay model for signalized intersections is assessed to identify where and when such deficiencies occur. Four signalized intersections within the Chicago central business district (CBD) area are selected to assess the accuracy of the HCM control delay model. The lane groups studied include three through lane groups and one permissive left-turn lane group. Input data (e.g. lane group volumes, proportion of vehicles arriving on green, effective green time, etc.) for the HCM model and empirical data (e.g. actual measured control delay) were collected cycle by cycle in the field. Saturation flow rates estimated from (a) the HCM default parameter values, (b) field calibration and (c) statistical optimization are entered into the HCM control delay model, respectively, to calculate control delays. Then, the control delays calculated from the model are contrasted to those measured from the field. For the through lane groups, the analysis indicates that the control delay calculated using the HCM default parameter values overestimates field delay in most of cases, and it may not accurately reflect the lane groups' performance. However, when field calibrated and/or optimized values are used, the control delay estimated using the model is close to that obtained from field measurements, and this indicates that the HCM control delay model is reliable. For the permissive left-turn lane group, no matter which values of saturation flow rate are used, the control delay estimated using the HCM model is not comparable with that obtained from field measurements due to the small sample size of the number of vehicles arriving per cycle, and other factors apparently not reflected in the delay.