The role of peripheral vision in vertical road sign identification and discrimination

Abstract

The role of peripheral vision in road sign identification and discrimination was investigated in two studies. Peripheral vision plays an important role in road signs perception due to their lateral positioning. In the first study 20 participants identified road signs presented at five levels of horizontal eccentricity (1.1°-12.4°), and two levels of vertical eccentricity (0°-2.5°). In the second study road sign discrimination was tested in a same-different discrimination task. The first study showed that a vertical offset of 2.5° degraded proportion correct rate by 9%. Proportion correct rate decreased from 79% to 41% in the transition from 1.1° to 12.4° of horizontal offset. The second study showed an accurate discrimination for road signs presented within a horizontal offset of 6.4°. Road signs with angular shapes and prominent vertexes as triangular or cross signs were better identified in peripheral vision than signs with more compact shapes (circular signs). Practitioner summary: Vertical road signs, due to their lateral positioning, are often perceived in peripheral vision. Horizontal and vertical eccentricity negatively impacts the driver's ability to correctly identify and discriminate traffic signs. The use of singular shapes and a design with simple pictograms and large contrasting areas strongly facilitate road sign perception in peripheral vision.

Road sign vision and driver behaviour in work zones

“…This data is even more significant when considering that the participants wore an eye tracker device, drove an unfamiliar car and knew that their driving behaviour was being studied. This frequency, however, does not take into account a possible involvement of peripheral vision in road sign detection and identification (Costa, Bonetti, Vignali, Lantieri, & Simone, 2018).…”

Urban Mid-Block Bicycle Crossings: The Effects of Red Colored Pavement and Portal Overhead Bicycle Crossing Sign

“…In real-world driving situations, where traffic patterns change in a highly dynamic way, quick fixations may occur, as in the case of this study [50][51][52][53][54][55][56].…”

Effects of median refuge island and flashing vertical sign on conspicuity and safety of unsignalized crosswalks

“…Velichkovsky, Domhoefer, Pannasch, & Unema (2000), for example, reported that fixations around 60 ms made up around 7% of all fixations during a simulated driving task. Short fixations in a driving task have been also reported by Sodhi et al (2002), who found a modal value for on-road fixation duration of 20 ms, and a modal interval for off-road fixations of 40-60 ms. Lantieri et al (2015) and Costa, Bonetti, et al (2018), found that in real traffic situations, due to the high dynamical context of road driving, mean fixation duration is much lower than in other contexts and experimental settings. In a real driving task, as in this study, car movements and the complex optical flow of the dynamical visual scene could cause very rapid fixations.…”

“…The main applications of mobile eye tracking studies in driving behaviour are steering, braking, multitasking, city driving and driving learning (Land & Tatler, 2009). In addition, eye tracking was also used to study drivers' detection, perception and acknowledgment of different road elements, to optimize the driving strategy and prevent accidents (Bongiorno, Bosurgi, Pellegrino, & Sollazzo, 2017;Costa, Simone, Vignali, Lantieri, Bucchi, & Dondi, 2014;Costa, Bonetti, Vignali, Lantieri, & Simone, 2018;Costa, Simone, Vignali, Lantieri, & Palena, 2018;Inman, 2012;Kapitaniak et al, 2015;Lantieri et al, 2015;Mantuano, Bernardi, & Rupi, 2017).…”

“…Since the distribution of fixation duration is positively skewed and not normal (Costa, Bonetti, et al, 2018; medians are reported instead of means.…”