Performance Based Operations Assessment of Adaptive Control implementation in Des Moines

Transcription

1 Performance Based Operations Assessment of Adaptive Control implementation in Des Moines Introduction The proposed study will evaluate the performance of multiple traffic adaptive signals operated using InSync Adaptive Control system. The following systems will be explored as potential candidates for evaluation: a. 1 st Street corridor b. 22 nd street c. I-80 DDI (Alice Rd) d. Mills Civic Pkwy e. North Jordan Creek Pkwy f. South Jordan Creek Pkwy g. University h. Valley West Dr. The adaptive control vendor (Rhythm Engineering Inc.) has agreed to share the data streams from the above mentioned corridors. Given that this is the first project of a new Iowa DOT program, the timely results will highlight the benefits of investment in adaptive control systems and will serve as an important reference in consideration of the suitability and selection of similar project across the state. Background Ashworth Rd 1 st Street 1 st Street Figure 1: 1 st Street Corridor Grand Ave N Arterial management has been traditionally done using time-of-day mode. In recent years, adaptive controls have been implemented at congested arterials as an option to improve mobility by providing traffic responsive control instead of implementing generic time based timing plans. It is essential for a traffic engineer to perform a detailed impact analysis of such a system to justify the cost of the system, better understand the workings and limitation of the system and fine tune the system for the existing conditions. This analysis will benefit in investment programming of future potential corridors. This also will ensure better understanding of volume variations across the corridors and corresponding control adaption. Performance of any signal control system will depend on the random variations of demand in the network under consideration. A manual single day turning movement and

2 queue length counts would not suffice to assess the impacts of using adaptive traffic signal control. To overcome this drawback, the study proposes to design a high resolution event based data logger using the traffic the signal controller. Rhythm Engineering Inc. has agreed to share all their data logger data at the resolution they archive. The following section describes analysis conducted on a sample data set shared by adaptive control vendor. The data was shared for 1 st street corridor (shown in Figure 1) was used to conduct a sample analysis. The analysis is broken down into following areas of investigation: 1. Potential data error 2. Phase Failures and Long Wait 3. Phase Distribution to check if one phase is being over served or under served 4. Queue length and delay by phase and by intersection 5. Two way progression 6. Temporal Cycle and Green Time distribution to understand on how dynamic is the program. Figure 2 a: Number of phase failures in a week Phase Phase Number of Vehicles Phase Phase Figure 2 b: Number of vehicles in queue Time of Day

3 Figure 2 c: Delay for through movement Figure 2d: Progression quality Figure 2e: Level of interference in platoon progression

4 Figure 2 a through e, shows several performance measures and their distribution over time and phases. These measures will be very useful in detecting anomaly in a recurring pattern and explore performance of signal timing during such an event. In general, three major area of benefits are touted for installation of adaptive control: i. Resource savings by avoiding re-timing for special events and better handling of unplanned events: The adaptive control should ideally handle any special event signal timing without/or with minimal human involvement. ii. Resource saving by avoiding aging of signal timing plans: The adaptive control should be able to gradually align to the long term changes in volume patterns without needing costly signal retiming projects, usually done every three to five years. iii. Saving of user cost by faster transition from over-saturated conditions: The adaptive control should potentially reduce the duration of time spent under over saturated conditions, usually identified by cycle failures for critical phases, and lead to a faster recovery of the system when the demand has subsided. Under ideal circumstances, adaptive control should potentially increase the net through put of the system thus delaying the onset of over saturated regime. It should better manage the queues to avoid spill-overs and grid lock conditions and gate the loading of the network thus reducing the delays with in the network. This project aims to evaluate the adaptive control system performance, across multiple corridors, to gain insight about its performance and shortcomings in all the above defined three categories. Video will be recorded for a sub sample to ensure that the anomalies can be verified using manual ground truth. The performance of the adaptive control system will be evaluated for handling of special events, over saturated condition and long term aging of plans. The system performance will also be studied across different corridors with special consideration for presence of preempt, handling of pedestrian traffic as well as over-all stability of the system. Tasks The following tasks have been identified to complete this evaluation Task 1. High resolution data access- Data will be requested for all the available corridors. Along with the historical data, a sample number of movements will be video recorded for manual ground truth. Task 2. Field data collection- Work with the vendor and City of Des Moines Traffic and Transportation staff to obtain the high resolution data across all the corridors. Task 3. Analysis- Conduct an analysis which provides a contrast for performance of the adaptive signal plans across multiple heterogeneous corridors. Task 4. Data Driven Decision Implementation- based on the findings from Task 3, identify what corridor characteristics are most impacted (positively) through use of adaptive signal control. Using INRIX data, consider how this information might be used to prioritize where adaptive control should be considered within Iowa. Task 5. Summary Report- Prepare final report which documents the findings from each task. This report will follow IHRB formatting standards. Project Personnel

5 This effort will be led by Dr. Anuj Sharma (PI) with support from Neal Hawkins and Skylar Knickerbocker (Co-PI s) all from CTRE/Iowa State University. Schedule This project is anticipated to take 18 months. Data collection is subject to the installation schedule for the traffic adaptive system. Budget The total cost for this study is $47,758 with a detail budget provided below.