Scholarly Works, Virginia Tech Transportation Institute

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https://hdl.handle.net/10919/89575

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Browsing Scholarly Works, Virginia Tech Transportation Institute by Content Type "Conference proceeding"

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    Does the Interaction between Vehicle Headlamps and Roadway Lighting Affect Visibility? A Study of Pedestrian and Object Contrast
    Bhagavathula, Rajaram; Gibbons, Ronald B.; Nussbaum, Maury A. (SAE International, 2020-04-14)
    Vehicle headlamps and roadway lighting are the major sources of illumination at night. These sources affect contrast-defined as the luminance difference of an object from its background-which drives visibility at night. However, the combined effect of vehicle headlamps and intersection lighting on object contrast has not been reported previously. In this study, the interactive effects of vehicle headlamps and overhead lighting on object contrast were explored based on earlier work that examined drivers' visibility under three intersection lighting designs (illuminated approach, illuminated box, and illuminated approach + box). The goals of this study were to: 1) quantify object luminance and contrast as a function of a vehicle's headlamps and its distance to an intersection using the three lighting designs; and, 2) to assess whether contrast influences visual performance and perceived visibility in a highly dynamic intersection environment. Both luminance and contrast of roadway visibility targets and a pedestrian were measured with a calibrated photometer at a realistic intersection. Both target and pedestrian contrast and luminance were substantially affected by the intersection lighting configuration, illuminance level, location at the intersection, and vehicle distance from the intersection. Objects also underwent changes in contrast polarity (positive to negative or vice-versa) as the distance between the vehicle and object changed. During these polarity transitions, objects became invisible because the contrast was zero. Negative contrast on targets was associated with higher visual performance. Within a given contrast polarity (positive vs. negative), visual performance depended on the magnitude of contrast, with higher contrast associated with higher visual performance. The relationship between pedestrian contrast and perceived visibility was complex, since pedestrians were often rendered in multiple contrasts. These findings have important implications for the lighting design of intersections and the development of nighttime pedestrian detection systems that rely on computer vision.
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    Examining senior drivers’ acceptance to advanced driver assistance systems
    Liang, Dan; Antin, Jonathan F.; Lau, Nathan (2019-09-10)
    Advanced driver assistance systems (ADAS) can help maintain seniors’ safety and mobility with their decline in cognitive and physical capabilities. An early step of investigating the adoption and merits of ADAS for senior drivers is examining the factors that influence senior drivers’ acceptance of the technology. This paper presents our modeling effort on the acceptance of 18 senior drivers towards adaptive cruise control (ACC) and lane control features after six weeks of naturalistic driving with study vehicles. Adapting the Technology Acceptance Model (TAM), our model is built on questionnaire data on perceived usefulness (PU), perceived ease of use (PEoU), usebased trust (T) and perceived satisfaction (PS) in predicting behavioral intention to use (BIU) ADAS. Two major findings in our modeling effort are that (i) perceived ease of use has significant influence on trust and (ii) perceived satisfaction has significant influence on behavioral intention to use.
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    WIP: The Feasibility of High-performance Message Authentication in Automotive Ethernet Networks
    Allen, Evan; Bowden, Zeb; Marchany, Randy; Ransbottom, J. Scot (2023-02-27)
    Modern vehicles are increasingly connected systems that expose a wide variety of security risks to their users. Message authentication prevents entire classes of these attacks, such as message spoofing and electronic control unit impersonation, but current in-vehicle networks do not include message authentication features. Latency and throughput requirements for vehicle traffic can be very stringent (<0.1 ms and >100 Mbps in cases), making it difficult to implement message authentication with cryptography due to the overheads required. This work investigates the feasibility of implementing cryptography-based message authentication in Automotive Ethernet networks that is fast enough to comply with these performance requirements. We find that it is infeasible to include Message Authentication Codes in all traffic without costly hardware accelerators and propose alternate approaches for future research.