Comparing Speed Estimations from a Moving Vehicle in Different Traffic Scenarios: Absence versus Presence of Traffic Flow

Abstract

The aim of this research was to study the performance in a speed estimation task of a passenger travelling in a real car in different scenarios: a closed track used in previous experimental studies was compared with interurban traffic environment involving a secondary road and a highway. At the same time, the effect of sex and driving experience on speed estimation was analyzed. Thirty-six participants (18 male and 18 female, half of each group being drivers and half non-drivers) estimated the speed of the car in which they travelled as passengers. The actual speed values varied in the range of 40-100 km/h for the secondary road, 70-120 km/h for the highway condition, and 40-120 km/h for the track. The results obtained for the track in previous studies Recarte, Conchillo, & Nunes, 2004 were replicated in the same condition and were also verified for the secondary road scenario. However, a different pattern of errors was found for the highway. From the viewpoint of psychophysics, the participants were more accurate on the without-traffic track than in real traffic conditions, considered as a whole. The differences found between road and highway are discussed. No effect was found for between-subject variables, sex, and driving experience. Keywords: speed estimation, subjective speed, traffic psychology El objetivo de esta investigación es comparar las estimaciones de la velocidad de un coche real circulando en diferentes escenarios: un circuito sin tráfico, utilizado en estudios experimentales previos, se compara con un escenario interurbano abierto al tráfico, consistente en un tramo de carretera convencional y un tramo de autovía. Asimismo se analiza el efecto del sexo y la experiencia de conducción sobre las estimaciones de la velocidad. Treinta y seis participantes (mitad varones, mitad mujeres y, por experiencia, mitad conductores y mitad no conductores) estimaron la velocidad del coche en el que iban sentados como pasajeros. Las velocidades a estimar variaron de 40 a 100 km/h en carretera, de 70 a 120 km/h en autovía, y de 40 a 120km/h en el circuito. Los resultados obtenidos en circuito replicaron los de estudios previos (Recarte y Nunes, 1996; Recarte, Conchillo y Nunes, 2004;, y también los obtenidos en carretera. Sin embargo, la estimación en autovía presentó un patrón de errores diferente a los anteriores. Desde el punto de vista de la psicofísica, los sujetos estimaron con más precisión en el circuito sin tráfico que en las dos condiciones de tráfico real, carretera y autovía, en su conjunto. Se comentan las diferencias entre carretera y autovía. No se encontraron diferencias debidas a las variables inter-sujetos, sexo y experiencia en conducción. Palabras clave: estimación de la velocidad, velocidad subjetiva, psicología del tráfico

Enhancing Speed Perception in Virtual Environments Through Training

“…Semb (1969) also studied passenger speed estimation and found a power function relationship that fit well with the passenger estimates, meaning that as vehicle speed increased, passenger estimate errors increased. Recarte and Nunes (1996) found a tendency for subjects to underestimate speeds at all levels, and the error in estimates decreased with increasing vehicle speeds, which agrees with previous studies (Conchillo, Recarte, Nunes, & Ruiz, 2006;Evans, 1970;Triggs & Berenyi, 1982). The errors in adjusted speed estimates also decreased as the target speeds increased.…”

“…From both experiments, gender was found to be a significant variable in the main variable analyses, with females having more accurate speed estimates than males. This finding does not agree with previous studies in real-world speed perception (Conchillo et al, 2006;Evans, 1970;Recarte & Nunes, 1996). Durke (2010) studied gender effects in a driving simulator and found no significance in gender except in one scenario, where males produced more accurate speed estimates when high speeds and optic flow were coupled with a low FOV.…”

“…The presence of opposing traffic has also been found to cause larger underestimations in speed than when traffic was absent (Conchillo et al, 2006). In driving simulations Panerai et al (2001) found that simulated nighttime driving caused nine percent higher produced speeds over daytime driving.…”

“…Other studies that showed the driving environment can affect speed perception include one in which Rutley (1975) altered peripheral stimuli when driving a constant speed so that drivers perceived that they were accelerating. The presence of opposing traffic has also been found to cause larger underestimations in speed than when traffic was absent (Conchillo et al, 2006). In driving simulations Panerai et al (2001) found that simulated nighttime driving caused nine percent higher produced speeds over daytime driving.…”

Effect of Driving Simulation Parameters Related to Ego-Motion on Speed Perception

“…When asked to drive at target speeds of 25 and 50 mph, drivers responded by driving at an average of 158% and 136% of the target speed respectively. Many past studies indicate that drivers tend to misperceive speed (drive faster than perceived) when driving in both real and virtual environments (Conchillo, Recarte, Nunes, & Ruiz, 2006;Recarte & Nunes, 1996).…”