d ri ve r fe e d ba ck signs
A Citywide Location-Allocation Framework for Driver Feedback Signs Optimizing Safety and Coverage of Vulnerable Road Users BY MINGJIAN WU, M.SC. UNIVERSITY OF ALBERTA
Background To help motorists travel a safe speed to minimize traffic fatalities and major injuries, road authorities have launched speed management programs and introduced various tools. One of them is Driver Feedback Sign (DFS), which consists of a radar for detecting the speed of an approaching driver, and an LED screen board for displaying the driver’s speed. Paired with a speed limit sign for the road, the driver receives instant feedback to encourage voluntary speed reduction. A typical DFS is shown here in Figure 1.
31
TRANSPORTATION TALK | SUMMER 2021
Figure 1. A driver feedback sign (DFS)
CREDIT: EVONNE WINCHIU DONAHER
Our recent work evaluated the safety impact of the DFSs, via before-and-after study using Empirical Bayes (EB) method, in urban areas and the results indicate that they can reduce collision frequencies by 31.0% to 44.9% for different collision severities (e.g., fatality), collision types (e.g., lane-changing), road types (i.e., collector vs. arterial) and intervention types (i.e., combining DFS with/without automated enforcement). The economic analysis found that the benefit-cost ratios if combining severe and Property-Damage-Only collisions, ranged from 8.2 to 20.2 indicating that the DFS can be an extremely economical countermeasure.
