The Work Zone Data Exchange (WZDx) data specification is part of a larger effort by the Federal Highway Administration (FHWA) to modernize work zone data. Prior to the Work Zone Data Initiative (WZDI) and the WZDx specification, there was no standard for handling the complexities of work zone data lifecycle management, work zone common core data elements, and their definitions. The specification itself was developed to provide a reference guide or standard method of digitally communicating work zone activities. Early versions of the specification focused on communicating work zone data elements to connected and autonomous vehicles. More broadly, work zones are dynamic and involve many stakeholders, and developing a standard definition for communicating work zone information digitally is essential to the increasing demands of agencies to become more data driven with their operations and maintenance activities. 

WZDx Version 1.x was developed to provide infrastructure owners and operators (IOO) the ability to transmit authoritative data to mapping and equipment manufacturers of connected and autonomous vehicles (CAV) with the goal of adding additional use cases in the future. In 2019, the Work Zone Data Working Group (WZDWG) was established to advance the WZDx specification. Several changes were identified and made to the specification before the release of version 2, such as adopting a relational model approach, eliminating nested tables, and making the specification more scalable. The GeoJSON format was also formally adopted by the group to facilitate easier use of the data by consumers. Road closure impact reporting was simplified to include partially closed, fully closed, and fully open options. Lane-level restrictions were added to the specification so that agencies could report work zone impacts for each lane of roadway, when available. 1 Subsequent versions of the specification include additional agency functions and additional external stakeholders. 

Work Zone Data Challenges

Only a few agencies have successfully implemented the work zone data specification into production. This low adoption rate exists despite a high degree of interest in the specification itself based on comments found on the official GitHub site and discussions between IOOs and the FHWA. Based on these comments and conversations, the slow adoption of the standard appears to stem from other roadblocks and challenges. Following is a list of challenges that agencies face in working with work zone data:

Efforts to advance and develop the specification can be found on the WZDx GitHub website, which is open and available to the public. The site also contains tools for validating JSON files and developing a data feed. These tools are currently only available for version 1.1, but version 2.0 tools are expected in the near future. In January 2021, the USDOT awarded nearly $2.4 million in WZDx demonstration grants across 13 states to aid adoption.

08-119 Research Products:

Integration of Smart Work Zone Data with the WZDx

Multiple agencies have or are beginning to make use of smart work zone data to enhance their work zone data and to integrate these data with their WZDx data feeds. Agencies like the Iowa Department of Transportation and the Kentucky Transportation Cabinet already have case studies on integrating smart work zone data. As part of the NCHRP 08-119 project, the team will develop detailed case studies, lessons learned, and associated recommendations resulting from the efforts of IDOT, KYTC, and several WZDx Demonstration project awardees.

Additional Resources:

Maricopa County Department of Transportation

Maricopa County Department of Transportation (MCDOT) is a regional agency responsible for maintaining roadways within the Phoenix metropolitan area in cooperation with the Arizona Department of Transportation (ADOT). Both agencies share responsibility for maintaining a regionally integrated traffic data-sharing entity, called AZTech, which serves as the central data-sharing system across the region’s traffic and emergency management agencies.

FHWA Work Zones Data Initiative

The purpose of the WZDI is to develop a recommended practice for managing work zone event data (WZED) and to create a consistent language, through the development of a data dictionary and supporting implementation documents, for communicating information on work zone activity across jurisdictional and organizational boundaries.