Driver responses to graphic-aided portable changeable message signs in highway work zones

Abstract

Portable changeable message signs (PCMSs) have been employed in highway work zones as temporary traffic control devices. Various studies showed that adding graphics to PCMS messages can provide advantages to traditional text messages, such as increasing legibility and improving the understanding of elderly drivers. This paper synthesizes the findings of a twophase research project aimed to investigate driver responses to graphic-aided PCMSs. Different text and graphic-aided PCMSs representing roadwork and flagger were set up in the upstream of highway work zones, and speed data of over 2,700 vehicles were collected with a series of five speed sensors to determine vehicle speed reduction. Nearly 1,000 on-site driver surveys were performed to identify driver preference on the added graphics. The results discovered that graphic-aided PCMSs reduced mean vehicle speed between 13% and 17%, and reduced the speed of passenger cars and trucks significantly differently depending on their locations in work zone. The results indicated that all drivers correctly interpreted the flagger graphic and two work zone graphics, and suggested that 52% to 71% of drivers preferred to see graphics in PCMS messages. The findings also revealed that driver age did not have a significant impact on driver preference on PCMS message format.

Driver Response to a Dynamic Speed Feedback Sign at a Freeway Exit Ramp Considering the Sign Design and Installation Characteristics

“…1 to 9 mph in school zones (12)(13)(14)(15), 1 to 6 mph in residential neighborhoods (16,17), 1 to 6 mph on high-speed arterials (12,(18)(19)(20)(21)(22)(23), 2 to 6 mph in speed transition zones (12,15,(24)(25)(26), 1 to 4 mph on rural highway horizontal curves (12,15,(27)(28)(29), 2 to 6 mph in rural highway work zones (15,30,31), and 2 to 10 mph in freeway work zones (15,(32)(33)(34)(35)(36)(37).…”

Evaluation of Two Improved Schemes at Non-Aligned Intersections Affected by a Work Zone with an Entropy Method

“…Portable changeable message signs (PCMSs) have been used in work zones to increase legibility. Graphic-aided PCMSs reduced the mean vehicle speed by between 13% and 17% and reduced the speed of passenger cars and trucks significantly differently depending on their locations in a work zone [24]. For reconstruction scheme evaluation, the level of service, negative economic benefit, and traffic environmental impact can be used as analysis and screen indexes.…”

“…One is the freeway work zone impact, including the influence of capacity [20], work zone influence area [21], and traffic flow prediction models [22], and so forth. The other category is the urban work zone impact, such as the urban travel OD matrix [23], alternative route selection studies [24], and traffic organization management [25], and so forth. While existing studies lack research on the work zone layout and corresponding road geometric layout, few research papers have focused on the rationality of the work zone layout and corresponding road layout.…”

Evaluation of Different Work Zone Road-Occupation Schemes for Monorail Construction

“…The first category pertains to the work zones on highways, encompassing aspects such as traffic capacity [16], work area impact area [17], and traffic flow prediction models [18]. The second category focuses on urban work zones, including studies related to urban travel origin-destination (OD) matrices [19], alternate route selection [20], and traffic organization management [21]. Existing studies have notably overlooked research into the layout and location selection of work zones, and there has been limited investigation into the corresponding rationality of work zone layout and road geometry design.…”