Bridge Engineering Center

About the research

The ability for agencies to notify vehicles that they are approaching a work zone has the potential to reduce crashes by increasing motorists’ awareness of the conditions. A critical element of this ability involves providing accurate work zone information and reducing the potential for false alerts that motorists ignore, which can be accomplished through connected temporary traffic control devices (cTTCDs) such as connected arrow boards. Guidance is needed for agencies on integrating work zone data into traffic management operations to enhance safety and efficiency. This study focused on cTTCDs such as connected arrow boards, connected traffic cones, and other smart devices that improve the accuracy of work zone information. The research documents the current state of the practice, evaluates various cTTCDs, and explores methods for their integration into an agency’s work zone management system through technology such as an advanced traffic management system (ATMS).

For a broad view of how arrow boards can be integrated, arrow board data were summarized across 18 states. In total, 498,358 arrow board activations were captured between January 2023 and August 2024. As the search radius around each arrow board decreased, the percentage of locations that were unambiguously associated with a single roadway increased, with 86.6% of locations being unambiguous at a search radius of 25 ft. In total, 62% of arrow board activations had the closest roadway within 50 ft of the arrow board, with a majority of arrow board activations within close proximity to a roadway and two-thirds of the closest activations being less than 25 ft.

In terms of the potential benefits, the arrow board activations near a work zone represented only 11.3% of the total activations in Wisconsin, 1.2% of the total activations in Colorado, and 31.1% of the total activations in Iowa. In Iowa, arrow board activations occurred on average 290 minutes before the reported start time and 0.99 miles before the reported start location for verified work zones and on average 139 minutes before the reported start time and 0.51 miles before the reported start location for estimated work zones.

The use of cTTCDs such as connected arrow boards is expected to continue to increase, which will result in the need for additional research to continue to explore how this information can be utilized for real-time and historical analysis. The potential for automating the process of associating arrow boards and work zones still faces implementation challenges, but these can be overcome with continued evaluation and deployment of cTTCDs.