Des Moines Intelligent Transportation Systems (ITS) Master Plan and Implementation

Challenge: The Des Moines traffic signal system was due for updates, and the City desired a phased plan to evaluate and update the existing intelligent transportation system, including traffic signal controllers and cabinets, detection of all modes of transportation, video observation, dynamic message systems, school flashers, communication systems, central management software and hardware and an overall traffic data management strategy. The vision for the intelligent transportation system also included the flexibility to accommodate connected and autonomous vehicle technology when available in the future.

Solution: As the foundation of the master plan, the existing City of Des Moines traffic signal and ITS infrastructure were inventoried and evaluated in order to determine the existing components currently deployed and their applicability/compatibility moving forward. Completion of the inventory consisted of opening over 450 traffic signal cabinets to document the cabinet’s components.

The fieldwork was performed efficiently and accurately utilizing an innovative use of the ArcGIS Data Collector application loaded onto iPhones and Android smartphones. The application utilized a pre-built data collection form and provided geo-tagging of intersection/cabinet photographs. The data from the application instantly synced with the ArcGIS Dashboard page and was viewable by in-office GIS staff completing real-time data collection reviews.

ITS Master Plan

The master plan utilized the Systems Engineering process to develop a Needs Assessment document and a Concept of Operations which defined the system’s needs and expectations from a stakeholder perspective. Ultimately, the master plan prepared a deployment strategy that details the phased deployment of the recommended infrastructure solutions, including the traffic signal management system, communications system, and related intelligent transportation system field devices, strategies, and technologies, as appropriate. The ITS Master Plan provided a full deployment schedule for the recommended system, with a focus on the initial 5-year phasing plan and associated costs.

ITS Implementation

The HR Green team has moved into the implementation phase with the City of Des Moines. The team has assisted the City in further evaluation of Advanced Traffic Management Software (ATMS) and advanced through the stages of PS&E package development. Phase 1 and 2 plan set packages have been let to the Contracting community. Phase 3 of the implementation plan is currently under design. This process has included coordination with the City’s IT department, verification of fiber optic assets and pathways including observations of OTDR testing with City staff, and fiber optic design.

Additionally, HR Green assisted the City in developing the following traffic signal standardization products; a Designer’s Checklist to aid in a consistent designer approach, a Template Plan Set to set the tone for typical traffic signal plan sets to be developed for the City, and a revision/current traffic signal special provision document which is layered from the Iowa SUDAS standard specifications.

Benefit: The ITS Master Plan project provides steps forward toward three of the City’s five 2021 overall city-wide goals; Upgraded Infrastructure, Livable Community, and Sustainable Community. The Des Moines transportation system updates work toward a future-proofed, resilient communications network using fiber optic cables while decreasing traffic congestion (with side benefits of improving air quality and reducing crash rates), increasing travel time reliability, and optimizing traffic flow along key corridors within Des Moines.