This project evaluated four traffic control devices over two years to assess their effectiveness in reducing vehicle speeds at roadwork sites. Year 1 trials included flashing beacons and speed radar signs, while Year 2 focused on video surveillance signage using variable message signs (VMS) and a portable temporary boom barrier (PTBB), both individually and in combination. Results showed that all devices contributed to some level of speed reduction, with the combined VMS + PTBB proving the most effective—significantly lowering average speeds and reducing the proportion of drivers exceeding the speed limit by more than 10 km/h by 37%. Statistical analysis confirmed meaningful effect sizes, with the combined treatment outperforming VMS alone. While speed reductions were minimal further from work zones, more pronounced impacts were observed closer to sites. Some limitations were noted, including reduced effectiveness of prolonged video surveillance messaging and practical challenges with flashing beacons. Overall, the study concludes that traffic control devices improve speed compliance, with the combined VMS + PTBB offering the strongest results, and recommends applying these findings with site-specific engineering judgement, with potential future research into combining speed radar signs and PTBB.
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