Smart Signaling by PTV Balance and PTV Epics

Collection of Data

National Capital Territory of Delhi was selected to demonstrate the advantages of PTV Balance and PTV Epics to ease the traffic problem and decrease the air pollution for a long life. A stretch of 3km long covering 6 signalized intersection was identified and the necessary traffic data was collected for the whole day. All the signalized intersection works on fixed time control but the cycle time and green time vary from peak to off peak hours of traffic.

The peak network traffic accounts for 8.8% during the evening peak hour which was observed during 1730-1830. Since Delhi accounts for one of the highest car ownership ratio, 60% of the traffic observed on the project network was car followed by two-wheeler which accounts 24% from the total traffic. From the data observed the average journey delay across the corridor was 269 seconds and the peak hour network speed observed to be 18.6kmph.

Data Provision and Workflow

The PTV Vision suites allows data provision for PTV Balance in a seamless way for simulation and calibration across different PTV platforms. A network of 3km stretch was modelled inside PTV Visum with Epics/Balance as local signal control at all the signalized intersection. With export and import functionality “anm” (Abstract Network Model) and “anmroutes” format model was imported back into PTV Vissim for simulation and calibration. Balance Central a signal control is coded inside PTV Vissim for integrating PTV Balance and PTV Epics for the network wide optimization. PTV Balance optimizes the corridor every 300 seconds with the local and global parameters.

PTV Balance and PTV Epics Advantages

PTV Epics and PTV Balance were integrated into the base model inside PTV Vissim and the simulation was carried out continuously to calibrate the model for the effective results. The PTV Balance uses web based user interface for thorough analysis and calibration of its calculation methods and traffic model. In order to have a balance network wide optimization, 120 seconds cycle time was adopted at all the signal controller along 3km project network. The fundamental parameters of the controls like signal groups, stages and interstages were not changed in order to enable installation of the new control strategies into the field. During the simulation run, every 300 seconds, PTV Balance initializes the optimization to have a smooth traffic movement by optimization of network.

During optimization, PTV Epics will optimizes individual intersection whereas PTV Balance will optimize the network through collecting the data from the detector. Depending on the traffic from each detector, the weightage to the different direction is specified to have an extended green for the respective direction of traffic.

After the multiple simulation runs by varying random seeds, the result shows the significant advantage after integrating PTV Balance and PTV Epics. The travel time, queue length and delay have
been reduced by around 25%-45%.

The weighted travel time result indicates 26% reduction over the fixed time signal controller.

The queue length from each approach arm was observed from the primary data and the weighted average for the individual junction was determined and the results from fixed time signal model and PTV Epics and PTV Balance models were compared. An average of 37% reduction on queue length over fixed time model could be observed. The average network delay shows 30% reduction over the fixed time model. A 27% increase in network speed is observed by integrating PTV Balance and PTV Epics with the signal controller.

One of the greatest challenge the world is facing today is that Environmental Pollution. The vulnerable one is that Air Pollution due to increase in the vehicle ownership. From the simulation environment, the emission level on Lodhi Road was calculated and it showed the significant reduction in carbon dioxide, nitrogen oxide and particulate matter which are referred as air quality index to measure the Air Pollution. By intelligent traffic signaling with PTV Balance and PTV Epics, pollution level could be reduced by 10%-15%.

The economic impact was calculated by the result obtained after intelligent traffic signal using PTV Balance and PTV Epics. If the system is implemented across all the signalized intersection in Delhi, then the annual time saving across the network was estimated to be Rs.215 Crores or USD $33 Million.

Detection Technology

The solution proposed for a non-lane based traffic is by cameras on each direction and a fish eye camera to monitor the complete junction. The success ratio of 80% – 90% of detection with the camera detection was a main advantage over the loop detection technology under non-lane based traffic. The control box is embedded with camera detection along with PTV Balance and PTV Epics on top of it and the system is flexible enough to integrate into existing signal controller. The control box has an ability to use the Bluetooth and GSM network for a seamless communication which is very much cost effective over the fiber optics cables for the transmitting the data. The communication protocol and other relevant specification are the information required to convert the existing fixed time controller into intelligent traffic signal controller. For each direction of traffic one camera will be placed at the height of 6-8m from the ground level to capture the vehicular record and one fish eye camera to monitor the turning movement
Prabhu TD, Transport Planner,  PTV MENAi Region Florian Weichenmeier,  Realtime Traffic Software, PTV Group AG Sonal Ahuja, Regional Director,  PTV MENAi Region and the overall performance of the junction.

The substantial parameters like travel time, network speed, journey delay and queue length show a significant advantage with PTV Balance and PTV Epics over the existing fixed time signal. PTV Balance and PTV Epics gives Green Light for all the roads.