Virginia Tech
    • Log in
    View Item 
    •   VTechWorks Home
    • VTechWorks Archives
    • VTechWorks Administration
    • All Faculty Deposits
    • View Item
    •   VTechWorks Home
    • VTechWorks Archives
    • VTechWorks Administration
    • All Faculty Deposits
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Does the Interaction between Vehicle Headlamps and Roadway Lighting Affect Visibility? A Study of Pedestrian and Object Contrast

    Thumbnail
    View/Open
    Submitted version (1.514Mb)
    Downloads: 18
    Date
    2020-04-14
    Author
    Bhagavathula, Rajaram
    Gibbons, Ronald B.
    Nussbaum, Maury A.
    Metadata
    Show full item record
    Abstract
    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.
    URI
    http://hdl.handle.net/10919/99275
    Collections
    • All Faculty Deposits [2289]
    • Scholarly Works, Virginia Tech Transportation Institute [33]

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us
     

     

    VTechWorks

    AboutPoliciesHelp

    Browse

    All of VTechWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Log inRegister

    Statistics

    View Usage Statistics

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us