The Effect of Design and Placement of Work-Zone Warning Signs on Driver Speed Compliance: A Simulator-Based Study

Abstract

OCCUPATIONAL APPLICATIONS In this work, simulated driving was used to test how characteristics of dynamic message signs impact driver behavior when entering designated work zones. Driver compliance with posted speed limits was measured in response to signs that differed in terms of placement distance and type of sign design. Signs should be placed farther ahead of the work zone to enhance speed compliance. Such compliance can also be enhanced by using concise sign content. TECHNICAL ABSTRACT Background and Rationale:In recent years, the number of occupational fatalities occurring as a result of workers being struck by vehicles while on the job has remained high. Fatalities are especially apparent at road construction sites, where nearly half of the fatal occupational injuries were classified as a worker being struck by a moving vehicle, highlighting the need for research to identify techniques to reduce the incidence of injury in future years. Purpose: This project investigated how the characteristics of a dynamic message sign can impact driver compliance with posted information in work-zone settings, specifically signs indicating speed reduction. Methods: Driving simulation was used to assess the effects of three placement distances (305, 457, and 610 m before the work zone) and four sign designs (differing in whether the sign was static versus dynamic and the amount of information presented). The study was completed by 39 participants, during which driving speed and compliance with speed change were recorded. Results: Placement of the speed-reduction signs impacted driver behavior, with greater placement distances being associated with higher speed reduction and compliance rates. Speed reduction was also significantly impacted by sign design, with the largest speed reduction apparent with signs that are static or with dynamic signs that presented one complete statement per display frame. Conclusions: To achieve greater driver compliance with speed limits within work zones, greater sign placement distance is preferred. The content of dynamic

Driver behavior and accident frequency in school zones: Assessing the impact of sign saturation

“…For school zones, these factors include types of school zones (school zone compared to playground) (Tay, 2009;Kattan et al, 2011), number of lanes (2-lane roads vs. 4-lane roads) (Tay, 2009;Kattan et al, 2011), presence of children (Kattan et al, 2011), length of the speed zone (Strawderman et al, 2013;Kattan et al, 2011), approach speed (Saibel et al, 1999;McCoy and Heimann, 1990), types of schools (elementary school vs. high school) (Day, 2007), presence of fencing (Tay, 2009;Kattan et al, 2011) etc. Kattan, et al, (2011) found that in the situation when there is 2-lane roads, roads with fencing, traffic control devices and the presence of speed display device or children, and zones that were longer, drivers' mean speeds were lower, and the rate of compliance was higher.…”

Research on the Relationship between Dynamic Message Sign Control Strategies and Driving Safety in Freeway Work Zones

“…Moreover, DMS control strategies affect the behavior of drivers in advance through compliance with speed reductions. For example, Strawderman et al [9] investigated the impacts of DMS control strategies and sign placement on the behaviors of drivers approaching work zones by testing four DMS strategies and three placement distances (1,000, 1,500, and 2,000 feet) using a driving simulator; the results indicated that the resulting reduction in the driving speed was significantly impacted by the strategy employed. However, recent studies have also explored the misapplications of DMSs in work zones and revealed that DMSs can often contribute to driver confusion and anxiety regarding their appropriate path.…”

“…The speed may have been influenced by the speed limit signs (limit speed = 80 km/h) that were set at the start of the control area, and drivers likely increased their speed when they noticed that their speed was lower than the posted speed limit. Notably, the speed of the vehicle approaching the start of a work zone impacts the safety immediately; consequently, several studies have investigated the work zone safety based on the approaching speed [9]. Strategy 2 had the maximum approaching speed (82 km/h > 80 km/h), and strategy 3 had the lowest (75 km/h).…”

“…Dynamic message signs (DMSs) have been shown to effectively influence driver behavior. DMSs have been widely used for traffic control in work zones in many countries (e.g., [7,8]; Hassan et al, 2012; [9]). However, for DMSs to 2 Journal of Advanced Transportation effectively influence the speed and compliance of drivers in work zones, drivers must be able to comprehend the messages of DMSs and obey the corresponding speed limits and control advice.…”

Evaluation of the effectiveness of portable variable message signs in work zones in United Arab Emirates

“…The study concluded that PVMS placed in advance of work zones is an effective tool in reducing driver speeds. Strawderman et al [10] investigated the distance at which the VMS can be placed before the work zone. The study showed that VMS was effective in decreasing the speed of a vehicle when it was placed 500 m away from the work zone, when drivers had enough time to reduce their speeds gradually while approaching the work zone.…”