IN THIS CASE STUDY YOU WILL LEARN:
- How Arizona DOT coordinated efforts with AZTech, a regional traffic management partnership in Phoenix, and Maricopa County for safer work zones.
- How the collaboration concentrated on three areas for safer work zones: Smarter Work Zones (SWZ), Integrating Regional Work Zone Data into one system, and Connected Vehicle Work Zone applications.
- How a successful pilot project on county road MC- 85 allowed demonstration of the benefits of SWZ technologies on arterial roads.
Earlier this year, one of Arizona Department of Transportation (ADOT) construction workers was struck and killed while setting up signs to alert drivers about pavement repairs on I- 10. Work Zone safety and mobility is important to U.S. Department of Transportation (USDOT), Arizona, other states and local agencies. AZTech, a regional traffic management partnership in the Phoenix Metropolitan area, aims to provide smarter and connected technology and data driven solutions to work zone issues through three related innovations. The first is the Smarter Work Zone (SWZ) effort. Arizona has a long history of being one of the nation’s pioneers in implementing SWZ technologies across freeway and arterial roadways. The notable freeway SWZ projects include I- 15 Virgin River Queue Warning, I- 17 at Central Ave Travel Time System, and SR64 - Grand Canyon Travel Time. With ADOT focused on freeway network, Maricopa County Department of Transportation (MCDOT) is focused on the arterial SWZ innovation. Maricopa Association of Governments (MAG) is the regional metropolitan planning organization, is leading technology pilots of Transportation Systems Management and Operations (TSMO) areas. The first national arterial SWZ initiative began with commitment to the federal Every Day Counts (EDC) initiative from MCDOT leadership. SWZ deployments are an example of such an innovation that helps EDC goals to enhance safety and reduce congestion.
A second area of effort is the Regional Work Zone Data Integration and Exchange. AZTech has successfully developed Regional Construction and Maintenance Information (RCMI) and migrated multiple work zone data formats to a standards- based Traffic Management Data Dictionary (TMDD) format that can be used by agency and private- sector systems. The goal is to collect and process construction road closure and lane restriction data from multiple agencies and provide one regional resource data for dissemination through AZ 511. To support connected and automated vehicle work zone information dissemination MCDOT, ADOT and MAG have also collaborated to lead the Work Zone Data Exchange (WZDx) Demonstration Project through the AZTech partnership. Work zones are one of the most challenging operational design domains for automated vehicles. Waymo and Uber are testing automated taxi services in the region. These companies are expected to consume the WZDx feed and provide feedback regarding all aspects of the data.
The third are is Connected Vehicle Work Zone applications for freight vehicles. The goal of the Innovative Connected Vehicle (CV) Work Zone application project is to improve safety and productivity of freight traffic. Currently, motor carriers frequently experience significant loss of efficiency and safety at work z ones. In 2016, ADOT and MCDOT initiated a Federal Motor Carrier Safety Administration grant as part of Commercial Vehicle Information Systems and Networks. This pilot project, with the technical expertise from the University of Arizona, incorporated connected vehicles into the SWZ system and led to the development of Road Side Unit (RSU) specific for work zone applications.
TSMO Planning, Strategies and Deployment
The ADOT and MCDOT SWZ initiatives followed the System Engineering process. However, there were no SWZ deployment examples available specific to arterials. A concept of operations was developed and a pilot site was selected for deployment. The arterial SWZ project included instrumenting proposed alternate routes when the work zone route exceeded the delay threshold. Four key locations for messaging and speed checks were identified which included actions to inform, alert, check and warn.
To ensure that data is exchanged effectively, data from RCMI system, construction and maintenance road and lane closure information is automatically integrated from local agencies and disseminated through the Regional Archived Data System (RADS) to Arizona 511. The key success of the project is to utilize the format the local agency uses for work zone data entries as agencies have limited resources to convert data to a standard format. The regional system standardizes the data at the central level. Currently, about 14,000 work zone events are disseminated annually through the system.
In 2019, MCDOT and ADOT led a pilot program through support from the USDOT to further enhance the Work Zone Activity Data (WZAD). The pilot created an Application Programming Interface (API) consistent with the WZDx v1.1 specification for freight vehicle application. This system is currently operational on a select set of corridors. The WZDx API has being updated to the WZDx v3.0 specification and AZTech is first in the nation to deploy specification. Today, the WZDx is being used for a 1.5- year MC- 85 SWZ. A second one- year work z one project implementation is occurring on the I- 10 freeway MC- 85 is a major freight corridor arterial.
ADOT and MCDOT also developed an in-vehicle work zone application based on the Connected Vehicle technology, called CV-Work Zone, which provides dynamic in- vehicle alerts and warnings to drivers. The application is based on 5.9GHz wireless communications. The goal is to improve freight vehicle safety and mobility in work z ones by providing contextually correct alerts and warnings to drivers. The alerts and warnings are formulated based on the collected situational data about the geometry of work zones and position and motion information of the vehicle. This application was developed and tested on two types of work zones (freeway and arterial).
Communications Planning and Execution
Information to the public about these initiatives included media outreach through AZTech partners. The team coordinated with national stakeholders to provide field demonstrations.
Outcome, Learnings and Public Benefit
The evaluation for the MC- 85 SWZ project documented benefits included:
- Reduced travel times in peak period directions.
- Increased speed compliance/reductions in speed due to SWZ.
- No fatalities or worker safety issues during SWZ deployment.
- No crashes caused by the SWZ equipment.
- Additional SWZ equipment was not a distraction to drivers.
The MC- 85 project allowed successfully demonstration of the benefits of SWZ technologies on arterial roads. Standardizing and integration of work zone data in the region provides a single data resource to third parties.
AZTech successfully demonstrated that WZDx standard can be leveraged for location specific in- vehicle message dissemination to improve safety. Connected vehicle systems can be successfully integrated to SWZ for work zone RSU deployment and address challenges such power needs. FCC licensing for mobile RSU at work zone locations is a challenge. The project also contributed to national connected vehicles stakeholders including auto manufacturers in developing a better understanding of connected vehicle work zone mapping for freeway and arterial roads.
- Smarter Work Zones Video – Maricopa County - https://www.youtube.com/watch?v=bxHbOXCCOxA&feature=youtu.be
- FHWA Work Zone workshop summary hosted in Arizona - https://content.govdelivery.com/accounts/USDOTFHWA/bulletins/2521dee#link_2