#193 Surtrac for the People: Upgrading the Surtrac Pittsburgh Deployment to incorporate Pedestrian Friendly Extensions and Remote Monitoring Advances

Principal Investigator
Stephen Smith
Start Date
Feb. 1, 2018
End Date
Aug. 30, 2019
Research Type
Grant Type
Technology Transfer
Grant Program
FAST Act - Mobility National (2016 - 2022)
Grant Cycle
2018 Traffic21


We propose to work with Rapid Flow Technologies, the commercial provider of the Surtrac smart signal system, to upgrade the Surtrac Pittsburgh deployment to incorporate the latest technology advances. These advances are encapsulated in the new Surtrac “Alpine” release (referred to below as Surtrac 2.0). Principal among the advances included in this release are (1) new coordination of traffic signals with pedestrian walk signals that will significantly increase pedestrian crossing time at intersections, (2) redesigned, web-based performance monitoring capabilities, and (3) enhanced predictive modeling of traffic flows from detector information, which improves overall traffic flow optimization.  In addition to providing these new capabilities, installation of this new release will prepare the City for its planned expansion of the adaptive signal network; if they are truly interested in expanding multi-modal, real-time signal control more ubiquitously through the City, then there is really no alternative to Surtrac and this will be a prerequisite.  Moreover, current prototyping efforts at CMU to integrate new pedestrian detection capabilities, to exploit vehicle-to-infrastructure communication for smart transit priority and other vehicle expediting services, and to provide pedestrians with disabilities technology for safe intersection crossing all require that the Pittsburgh Surtrac deployment be consolidated to run the latest release. The current deployment has grown incrementally over the past 5 years, and operates with different versions of the system in different sections of the deployment. 

We propose a four-month project to systematically install Surtrac 2.0 at all 50 intersections of the current Pittsburgh deployment. In addition, we will address selected issues that have accumulated at various intersections, including an outstanding detection problem at Penn and Dallas Avenues that limits the system’s ability to perceive traffic buildup on Dallas Avenue at various times of the day, and a malfunctioning communication radio at Morewood Avenue and Baum Boulevard. We expect the new release to significantly extend pedestrian crossing time at intersections with little or no adverse impact on vehicle traffic flow efficiency. 
Rapid Flow Technologies’s recent deployment of Surtrac in Atlanta GA has led to consolidation of a new Surtrac 2.0 release that incorporates several new technology advantages that are either not currently supported in the Pittsburgh deployment or have only been deployed selectively at a small number of intersections. This project proposes to rectify this situation and upgrade the entire Pittsburgh Surtrac deployment to Surtrac 2.0. In the process we will perform specific upgrades that detection capabilities and communication infrastructure that have limited recent Surtrac performance.

Specifically, we propose to carry out the following tasks:

Task 1: Surtrac 2.0 installation - We will install Surtrac 2.0 at all 50 intersections of the current Pittsburgh deployment. For each deployed Surtrac processor (computer), this will first involve installation of a new Linux operating system, and then the Surtrac 2.0 system. We will acquire a small number of additional computers to enable off-line configuration of machines and swapping of computers in selected special circumstances, but for most intersections we expect to be able to accomplish the install remotely using our wireless back-haul connection. As we bring up the new Surtrac 2.0 release at a given intersection, we will re-verify the adequacy of current detector zone configurations (camera or radar) recalibrate as necessary. 

We will reinstall the network incrementally in sections (1) to facilitate incorporation of master-slave intersection coordination capabilities unique to the Pittsburgh network into Surtrac 2.0 early on (Task 2 below) and (2) to enable incremental testing of portions of the network during the installation period.

Task 2: Master-Slave intersection coordination – One capability essential to performance in the Pittsburgh Surtrac deployment is a master-slave intersection coordination capability for closely spaced intersections. This capability is not currently incorporated in the Surtrac 2.0 release that was deployed in Atlanta, but needs to be added for retrofit into the Pittsburgh deployment. This task involves extension of the Surtrac 2.0 scheduling capability to enable configuration of master-slave intersection pairs, and coordinated operation.

Task 3: Detection and communication upgrades – This task involves the installation of detection and communication hardware at specific intersections to overcome current deficiencies in the Pittsburgh Surtrac deployment. Specifically, this task will address the following:
o	Advance detection at Penn and Dallas Avenues – PennDOT’s original deployment of radar detection along the Point Breeze section of Penn Avenue included only advance detection along Penn Avenue and only stop bar detection on the cross streets. Generally this is workable (if not really sensible), but at Dallas there is significant cross traffic that warrants advance detection in the southern direction (toward Squirrel Hill). This task involves installation of an advance radar unit at Penn and Dallas Avenues capable of detecting queues and approaching traffic from the south on Dallas. [Installation will require in-kind effort of the Pittsburgh Public Works Department].
o	Replacement of broken radio at Baum Boulevard and Millvale Avenue – This task involves replacement of the current malfunctioning communication radio. [Installation will require in-kind effort of the Pittsburgh Public Works Department].
o	Coordination of Centre/Negley Avenues intersection and Negley/Giant Eagle intersection – The latter intersection still needs calibration to properly coordinate with the former.

Task 4: Testing and evaluation – This task involves testing and assessment of the Surtrac 2.0 installation. We expect Surtrac 2.0 to perform at a level equivalent to the current deployment from the standpoint of vehicle traffic flow efficiency while significantly increasing pedestrian crossing time. It is also possible that improvements in how Surtrac models approaching traffic could lead to better vehicle traffic flow efficiency. This task will measure these performance impacts.

We will coordinate with the City of Pittsburgh’s Department of Mobility and Infrastructure to announce this upgrade accomplishment sometime in May 2018. This announcement will be significant with respect to pedestrian traffic -  we will provide data indicating the substantial boost to pedestrian crossing times that the upgrade has realized throughout the Pittsburgh deployment. We will also provide data that characterizes the additional performance improvement to vehicle movements that have been achieved.     

(1) Carry out operating system upgrades for all processors in the field
(2) Complete technical upgrades to produce Surtrac 2.0

(1) Deploy Surtrac 2.0 
(2) Conduct evaluation and coordinate with the City for turn over.

Deployment Plan
The new version of Surtrac will be fully deployed by April 2019.    
Expected Accomplishments and Metrics
The project will result in (1) significantly greater amounts of walk time for pedestrian traffic, (2) further improvements to overall vehicle flows, and (3) preparation of the Pittsburgh Surtrac network for further RDD of new technologies (e.g., pedestrian detection capability) and for further expansion of Surtrac to additional intersections on the East End and elsewhere.    

Individuals Involved

Email Name Affiliation Role Position
isaack@cs.cmu.edu Isukapati, Isaac Carnegie Mellon University Other Faculty - Researcher/Post-Doc
sfs@cs.cmu.edu Smith, Stephen Carnegie Mellon Heinz College PI Faculty - Tenured


Amount of UTC Funds Awarded
Total Project Budget (from all funding sources)


Type Name Uploaded
Presentation Decentralized Optimization of Urban Traffic Flows , Phoenix AZ, Nov 4-7, 2018. March 27, 2019, 2:49 p.m.
Progress Report 193_Progress_Report_2018-09-30 Sept. 29, 2018, 10:48 a.m.
Publication Pittsburgh expanding system of 'smart' traffic lights to ease congestion Dec. 5, 2018, 5:03 a.m.
Publication Bi-Directional Information Exchange in Decentralized Schedule-Driven Traffic Control March 27, 2019, 2:49 p.m.
Progress Report 193_Progress_Report_2019-03-30 March 27, 2019, 2:50 p.m.
Final Report 193_-_Final_Report.pdf Jan. 27, 2020, 10:49 a.m.

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