#63 Traffic control devices in temporary traffic management

As noted in a previous brief, minimising workers’ exposure to traffic is key to improving roadwork safety. Common approaches to reducing worker and traffic controller exposure include the use of portable stop/slow devices such as portable traffic lights, boom gates, and electronic variable message signs (VMS).

Recently published research by Deakin University explored the motivators and barriers for the use of portable traffic control devices in Australia, with some interesting findings regarding reported frequency of use, effectiveness and related challenges[1]. Personnel from 54 companies involved in temporary traffic management were interviewed (n=12) or participated in an online survey (n=42). Summarising key findings of the study, the authors stated that:

…while Supplemental Traffic Control Devices (STCDs) are generally used to improve safety, there is no consistent approach to guidelines, practices, or device selection nationwide. Key challenges identified by traffic control companies include the high cost of STCDs, insufficient training, and rapid technological advancements that sometimes lead to reliability issues. These factors can discourage the industry from using STCDs regularly.

Frequency and perceived effectiveness of use

Study results suggested that human flaggers remain the most commonly used form of traffic control at stop/slow roadwork points, with 92% of respondents using this method at least sometimes (and 14% always). Portable traffic lights were reportedly used at least half of the time by around 50% of participants. Portable boom gates were less often used, and being relatively new in Australia, more than a third of participants had no experience with these devices. Factors such as device cost and reliability were among the barriers to greater use of devices, but it is also noted that site conditions and work duration can also be highly influential.

Other key factors, of course, are the effectiveness of devices and ease of use. Looking at portable traffic lights and boom gates specifically for stop/slow situations, traffic lights were generally considered to be highly effective, as shown in Figure 1. Most respondents (53%) considered portable traffic lights ‘easy’ to use, compared with 28% for boom gates.

In conclusion, there is considerable scope to increase the adoption of STCDs as an alternative to human flaggers and to improve their effectiveness by addressing some or all of the barriers noted in the study.

[1] Debnath, A., Blackman, R., & Siriwardene, S. (2025). Barriers and Motivators of using Supplemental Traffic Control Devices in Work Zones. Transportation Research Record, November 2025. https://doi.org/10.1177/03611981251384968