The Delays For Signalized Intersection Using Atcs Data And Field Survey Method (Case Study At Simpang Tiga Kerten, Surakarta)

The increasing of traffic volume in Surakarta has caused an increasing of congestion in several road networks. One of traffic jam phenomenon at intersection especially in peak hour can be found at some signalized intersections and roads especially in Simpang Tiga Kerten. It is located at the meeting between Jl. Slamet Riyadi and Jl. Ahmad Yani, Surakarta. The Local Government through the Communication, Informatics and Transportation Department (Dishubkominfo) Surakarta is developing integrated traffic management control system named Area Traffic Control System (ATCS). The aim of ATCS is to enable the vehicle movement continuously and minimize the delay in intersection (Risdiyanto, 2014). Traffic delay at signalized intersection is used as an indicator to evaluate the performance of intersection refers to MKJI 1997. The using of MKJI 1997 method for the traffic condition at present needs to be evaluated. The delay value needs to be compared with the result of field survey method using ATCS. The implementation of manual traffic counts survey carried out for a day mainly at morning peak hour (06:00-07:00 AM). It is sourced from traffic counting data from ATCS detector of Dishubkominfo Surakarta after converted in passanger cars unit. The obtained data from field observation for calculating field delay are number of waiting vehicle every15 seconds, stopped (in red and amber time) and not stopped vehicles (in green and amber time). The average delay values by MKJI 1997 method at Simpang Tiga Kerten, Surakarta is 105.50 sec/pcu, while the average field delay values is 16.19 sec/pcu. Based on the comparison, it can be known that the field delay is lower than MKJI 1997 delay. It is caused by the differences in withdrawal traffic flow data that will be used in delay calculation analysis. Inaccurate of determining the adjustment values (which are: effective width, city size, side friction, turning movement, vehicles stopped ratio and turn at each approach will also cause inaccurate in the delay value

Measuring delays for bicycles at signalized intersections using smartphone GPS tracking data

The article describes an application of global positioning system (GPS) tracking data (floating bike data) for measuring delays for cyclists at signalized intersections. For selected intersections, we used trip data collected by smartphone tracking to calculate the average delay for cyclists by interpolation between GPS locations before and after the intersection. The outcomes were proven to be stable for different strategies in selecting the GPS locations used for calculation, although GPS locations too close to the intersection tended to lead to an underestimation of the delay. Therefore, the sample frequency of the GPS tracking data is an important parameter to ensure that suitable GPS locations are available before and after the intersection. The calculated delays are realistic values, compared to the theoretically expected values, which are often applied because of the lack of observed data. For some of the analyzed intersections, however, the calculated delays lay outside of the expected range, possibly because the statistics assumed a random arrival rate of cyclists. This condition may not be met when, for example, bicycles arrive in platoons because of an upstream intersection. This justifies that GPS-based delays can form a valuable addition to the theoretically expected values

Broadening Understanding of Roundabout Operation Analysis: Planning-Level Tools and Signal Application

In United States, roundabouts have recently emerged as an effective and efficient alternative to conventional signalized intersections for the control of traffic at junctions. This thesis includes two investigations related to the operations of roundabouts. The first investigation examines the ability of a planning-level tool (the critical sum method) to serve as an indicator variable for the results of the Highway Capacity Manual’s average delay per vehicle measure for a roundabout facility; to what extent do the results of one predict the results of the other? The critical sum method was found to accurately predict the HCM average delay per vehicle for low-volume conditions, approximately up to an average delay of 15 seconds per vehicle, but the tool was found to provide inaccurate predictions for higher volume conditions. The second investigation looks at the potential of metering signals on a roundabout facility to transfer excess capacity from a low-volume approach to an adjacent higher-volume approach. The analysis indicated positive results for the theoretical benefits of the metering signal when only placing simulated traffic on two of the approaches, but the results were not duplicated when analyzing more-realistic volume scenarios with traffic on all four approaches. Advisor: John Sangster

Estimating Delay of Vehicles in Nearside Legs of the Signalized Intersections under Expectation Method in Under-Saturation Conditions for Isolated Intersection

Signalized intersections are essential elements of road transport in cities, thus providing condition in which these key elements have optimal performance in different traffic conditions has always been a concern for traffic engineers. Normally, Average vehicle control delay (delay due to the presence of traffic lights) is used as performance indicators on signalized intersections that is estimated using a lot of equations, including the Webster, Green Shields and the equation described in the book "Highway Capacity Manual". But in these equations no place is include for the distribution of vehicles on the routes leading to the signalized intersections. Ignoring this issue could lead to a false estimate of the average amount of delay on the signalized intersections because of the type of their entrance resulting in inefficient operation of the intersection. Using Expectation Method, this paper proposes a better estimate of the amount of delay on the vehicles in signalized intersections, depending on frequency of entrance to the intersection. In the end it will be found out that different frequency distribution of vehicles at nearside legs of intersection lead to different delay estimates of vehicles

Estimating delay at a signalized intersection using queuing models

Abstract: Intersections have been identified as the most complex location in a traffic system. This is due to the number of movements that occur within an intersection. Delays have a negative impact on motorists as well as in the economy. Traffic signals are implemented to reduce this burden, but this is determined by the signal timing. The pre-timed traffic signal control assigns the right of way at an intersection according to predetermined schedule; and does not accommodate short-term fluctuations. The purpose of this study was to estimate the delay at an intersection using queuing models. The study uses field data collection

Modeling Capacity and Delay at Signalized Intersections with Channelized Right-turn Lanes Considering the Impact of Blockage

Right-turn channelization is used to improve the capacity at busy intersections with a lot of right-turns. However, under heavy traffic conditions the through lane vehicles might backup and block the right-turn lane. This will affect the discharge rate of right-turning vehicles and reduce the approach capacity and, consequently, increase the approach delay. So if the right-turn channelization is blocked frequently, its advantage is neglected and serious capacity problems can be overlooked. This issue is not addressed in the Highway Capacity Manual (HCM) and no separate model is provided to estimate the capacity and delay of approaches with channelized right-turn lanes. Using conventional methods for estimating the capacity and delay without considering the effect of potential blockage results in overestimation of the approach capacity and underestimation of the approach delay. This research presents probabilistic capacity and delay models for signalized intersections with channelized right-turn lanes considering the possibility of the right-turning vehicles being blocked from accessing the lane.The capacity model was developed by considering the capacity under blockage and non-blockage conditions with respect to the probability of blockage. Subsequently, a model was developed to estimate the probability of blockage. The capacity model is significantly affected by the length of the short-lane section and proportion of right-turn traffic. The proposed capacity model under blockage conditions and also the blockage probability model were validated through VISSIM, a microscopic simulation model. The validation process showed that both models are reliable. For operational purposes, the recommended lengths of the short-lane section were developed which would be useful in evaluating adequacy of the current lengths, identifying the options of extending the short-lane section length, or changing signal timing to reduce the likelihood of blockage. The recommended lengths were developed based on different signal timing plans and several proportions of right-turn traffic. The queue accumulation polygons (QAPs) were used to estimate the approach uniform delay and the HCM procedure was followed for the computation of the incremental delay caused by the random fluctuation of vehicle arrivals. To investigate the effect of blockage on the uniform delay, two different QAPs were developed associated with arrival scenarios under blockage and non-blockage conditions. The proposed delay model was also validated through VISSIM. It was found that, the proposed model can provide accurate estimates of the delay by reflecting the delay increase due to the right-turn channelization blockage. The results showed that the delay of an approach with a channelized right-turn is influenced by the length of the short-lane section and proportion of through and right-turn traffic

The Analysis Method of Capacity and Delay on Entrance Lane with Road-side Bus Lane

In order to reveal the traffic characteristics at signalized intersections with road-side bus lane, the analysis methods of capacity and delay at entrance lane were studied. Selecting a signalized intersection with road-side bus lane as investigation location, several traffic parameters were surveyed. Considering the traffic conflict between right-turn vehicles and through buses in this kind of entrance lane and based on the Gap Acceptance Theory, the calculation model of saturation flow rate, which is a key parameter both in the formulas of capacity and delay at signalized intersection mentioned in HCM2000, was improved. Using the investigation data, the calculation results of the traditional model and improved model were compared and analyzed. The research indicated that, comparing with common entrance lane, the capacity of right-turn lane at the entrance lane with bus lane should be reduced, and the travelling delay of bus lane and its inside adjacent lane should be increased. The degree of these effects is related to bus volume, right-turn volume and headway between buses