Demonstration of a Secondary Warning Device for Roadway Workers in Sacramento Reports Technical Issues and Limitations While Using the Technology.
Sacramento, California, United States
Roadway Worker Protection Secondary Warning Device and Employee in Charge Software System (EICSS)
Summary Information
Through partnership with the Federal Transit Administration (FTA), the Sacramento Regional Transit District (SacRT) conducted a demonstration test of a secondary warning device for roadway workers in 2018. The commercially available secondary warning system consists of a roadway worker protection (RWP) system mounted in a rail vehicle and a personal alert device (PAD) worn by a roadway workers. This secondary RWP system design provides a visual and audible advance warning alert to train operators of workers ahead and a visual and audible advance warning to alert wayside track workers of approaching trains. The second phase of the project implemented the Employee in Charge Software System (EICSS) that uses smartphone technology to validate and authorize roadway worker access to a section of track.
A system assessment was performed that measured effectiveness in terms of work zone intrusion rates and employee survey responses.
Technical issues with the warning device suggested a wide range of lessons learned during the project, summarized below:
- Understand that the use of electronic devices in active trackway could be a distraction to frontline workers. Frontline workers experienced alert fatigue within days of use, as train indications became a nuisance and could not be silenced, leading to waiver to halt use in Downtown areas where close track configurations did not suit technology.
- Avoid using the technology in city centers or in small area with close track configurations due to the constant alarms of incoming trains. As a result, frontline workers had difficulty understanding where the signal was coming from in Downtown areas.
- Check if the system capability meets the agency’s requirements. The demonstrated system limited communication to two individuals (controller and frontline employee), and as a result, removed communication with the operator from the process.
- Understand the limitations in collecting measurable assessments through personal device usage, especially in the early testing stages when frontline workers did not fully understanding how the device worked.
- The system may not discern between adjacent tracks. As a result, all track workers in proximity of the approaching train were warned and not just workers on the occupied track.
The following lessons learned are from the overall project:
- Expect challenges associated with the capabilities of first-generation technology deployments. Examples of such challenges include difficulties with triggering of alerts and false positive alerts due to the operating environment.
- Track software revisions with a change report. Doing so can help streamline the validation and approval process associated with revisions.
- Consider local regulatory requirements prior to deploying technologies to avoid lengthy delays associated with testing and validation.
