RESUMEN
Objective: Drivers have difficulty deciding whether to stop at the stop line or proceed through the intersection at the onset of the circular yellow (CY) indication. The purpose of this study was to understand how drivers distribute their visual attention when the traffic signal turns to the CY indication at high-speed signalized intersections, and whether factors such as time to stop line, headway or following vehicle type, influence overt visual attention.Method: Data included eye-tracking metrics from 45 participants during a 24-scenario driving simulator experiment. Three areas of interest (AOIs) were defined (traffic signal, rear view mirror, and side view mirrors).Results: Results showed that while the CY indication was displayed, total fixation durations (TFDs) were highest on the traffic signal (626 s), lower for the rear view mirror (50 s), and lowest for the side view mirrors (3 s). Repeated-measures ANOVAs indicated that the type of following vehicle influenced TFDs. Being followed by a heavy vehicle resulted in drivers shifting their fixations away from the traffic signal. Drivers fixated on the traffic signal more when followed by a passenger car than they did when followed by a heavy vehicle. Additionally, higher time to stop lines resulted in greater TFDs on the traffic signal.Conclusions: This study highlights the importance of understanding the fixation behavior of drivers and the factors that influence drivers' visual attention. These findings could guide future efforts by the transportation community to involve drivers in training programs to emphasize the risks associated with ignoring rear view mirrors during their response to CY indications.
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Atención , Conducción de Automóvil/psicología , Fijación Ocular , Adolescente , Adulto , Anciano , Entorno Construido , Toma de Decisiones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
INTRODUCTION: While sophisticated plans have been adopted nationally and globally to increase bicycling's share of daily commutes, safety concerns have negatively impacted targeted bicycling growth. To investigate people's preferences for bicycling in dense urban areas, it is important to recognize how bicycling perceived level of comfort (PLOC) is constructed and how it could relate to safe versus risky behavior while interacting with motorized modes of transportation. METHOD: To examine these issues, we analyzed results from an online survey with 342 participants. Structural Equation Modeling (SEM) was employed to systematically investigate the construct of bicycling PLOC and simultaneously analyze bicyclists' responses to the presence of a truck in the adjacent lane near an urban loading zone. RESULTS: SEM estimation results indicated that participants who said that they engaged in more frequent distracted bicycling reported lower PLOC. On the other hand, those who felt that road users were more lawful and predictable, and who had more bicycling experience, reported higher levels of PLOC. Participants who bicycled for commuting purposes, who made shorter trips, who bicycled more frequently, and who had more exposure to downtown bicycling also reported higher levels of PLOC. Finally, findings showed that higher PLOC was significantly associated with the choice of a safe, rather than a risky response to the presence of a truck, suggesting that a way to improve bicyclist safety would be to build an environment that could increase bicyclists' PLOC.
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Accidentes de Tránsito/estadística & datos numéricos , Ciclismo , Seguridad/estadística & datos numéricos , Adulto , Anciano , Ciudades , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vehículos a Motor , Oregon , Asunción de Riesgos , Adulto JovenRESUMEN
There is little research on the behavioral interaction between bicycle lanes and commercial vehicle loading zones (CVLZ) in the United States. These interactions are important to understand, to preempt increasing conflicts between truckers and bicyclists. In this study, a bicycling simulator experiment examined bicycle and truck interactions. The experiment was successfully completed by 48 participants. The bicycling simulator collected data regarding a participant's velocity and lateral position. Three independent variables reflecting common engineering approaches were included in this experiment: pavement marking (L1: white lane markings with no supplemental pavement color, termed white lane markings, L2: white lane markings with solid green pavement applied on the conflict area, termed solid green, and L3: white lane markings with dashed green pavement applied on the conflict area, termed dashed green), signage (L1: No sign and L2: a truck warning sign), and truck maneuver (L1: no truck in CVLZ, L2: truck parked in CVLZ, and L3: truck pulling out of CVLZ). The results showed that truck presence does have an effect on bicyclist's performance, and this effect varies based on the engineering and design treatments employed. Of the three independent variables, truck maneuvering had the greatest impact by decreasing mean bicyclist velocity and increasing mean lateral position. It was also observed that when a truck was present in a CVLZ, bicyclists had a lower velocity and lower divergence from right-edge of bike lane on solid green pavement, and a higher divergence from the right-edge of bike lane was observed when a warning sign was present.
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Accidentes de Tránsito , Ciclismo , Comunicación , Planificación Ambiental , Vehículos a Motor , Asunción de Riesgos , Accidentes de Tránsito/prevención & control , Adulto , Ingeniería , Femenino , Humanos , Masculino , Seguridad , Adulto JovenRESUMEN
A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes.
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Accidentes de Tránsito/prevención & control , Conducción de Automóvil/psicología , Ciclismo/psicología , Planificación Ambiental , Adulto , Anciano , Atención , Conducción de Automóvil/legislación & jurisprudencia , Distribución de Chi-Cuadrado , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Seguridad , Adulto JovenRESUMEN
CONTEXT: Backing crash injures can be severe; approximately 200 of the 2,500 reported injuries of this type per year to children under the age of 15 years result in death. Technology for assisting drivers when backing has limited success in preventing backing crashes. OBJECTIVES: Two questions are addressed: Why is the reduction in backing crashes moderate when rear-view cameras are deployed? Could rear-view cameras augment sensor systems? DESIGN: 46 drivers (36 experimental, 10 control) completed 16 parking trials over 2 days (eight trials per day). Experimental participants were provided with a sensor camera system, controls were not. Three crash scenarios were introduced. SETTING: Parking facility at UMass Amherst, USA. SUBJECTS: 46 drivers (33 men, 13 women) average age 29 years, who were Massachusetts residents licensed within the USA for an average of 9.3 years. Interventions Vehicles equipped with a rear-view camera and sensor system-based parking aid. MAIN OUTCOME MEASURES: Subject's eye fixations while driving and researcher's observation of collision with objects during backing. RESULTS: Only 20% of drivers looked at the rear-view camera before backing, and 88% of those did not crash. Of those who did not look at the rear-view camera before backing, 46% looked after the sensor warned the driver. CONCLUSIONS: This study indicates that drivers not only attend to an audible warning, but will look at a rear-view camera if available. Evidence suggests that when used appropriately, rear-view cameras can mitigate the occurrence of backing crashes, particularly when paired with an appropriate sensor system.