00714888

Component

http://onlinepubs.trb.org...trr/1995/1495/1495-015.pdf

https://scholar.google.co...nell&publication_year=1995

The technical literature was reviewed with respect to the loss of visibility distance caused by automobile windshields or other optical filters. A series of nighttime luminance measurements in the field provided baseline data for a visibility distance computer model that was developed to investigate nighttime visibility of diffusely reflective targets under low-beam illumination conditions seen through automobile windshields having different transmittances. The computer model offers three alternative luminance contrast threshold models: (a) Adrian's target visibility algorithm, (b) PCDETECT, and (c) Blackwell's 1946 contrast threshold data. The new model, which is based on Blackwell's 1946 data, considers the effects of age and observation time and determines the actual contrast from the target luminance, which depends on the target reflectance, the selected headlamps, and the current observation distance. Percent visibility distance loss graphs, as a function of the initial visibility distance (D sub 0) (using no windshield) were established. A tentative field factor of 2.28 for the Blackwell data was determined. The obtained percent visibility distance loss data were compared with those published earlier by Haber in 1955. This comparison indicates that the percent distance loss functions shown by Haber are misleading and wrong because they are proposed to apply for a target with a constant mean linear dimension of 91.4 cm (3 ft) over the entire initial visibility distance range. Furthermore, the data presented by Haber are conservative and too high. On the basis of the results of this investigation, it would appear to be of benefit to further validate the results in the field and to review the appropriateness of established minimum luminous transmittance standards.

This paper appears in Transportation Research Record No. 1495, Traffic Control Devices, Visibility, and Railroad Grade Crossings. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01399828

English

p. 128-139

1995

Transportation Research Record

0309061601

Figures (5) ; References (21) ; Tables (3)

Algorithms; Automobiles; Computer models; Contrast; Field tests; Guides to the literature; Literature reviews; Loss and damage; Luminance; Night; Tinted glass; Tracking systems; Visibility distance; Windshields

Field measurements; Thresholds

Highways; Safety and Human Factors; Vehicles and Equipment; I91: Vehicle Design and Safety

TRIS, TRB

Dec 12 1995 12:00AM

• APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS TO RAIL-HIGHWAY GRADE CROSSING SAFETY
• COMPARATIVE STUDY OF ADVANCE WARNING SIGNS AT HIGH SPEED SIGNALIZED INTERSECTIONS
• CURVE RADIUS PERCEPTION ACCURACY AS FUNCTION OF NUMBER OF DELINEATION DEVICES (CHEVRONS)
• DETECTABILITY OF PAVEMENT MARKINGS UNDER STATIONARY AND DYNAMIC CONDITIONS AS A FUNCTION OF RETROREFLECTIVE BRIGHTNESS
• EFFECTIVE USE OF VARIABLE MESSAGE SIGNS: LESSONS LEARNED THROUGH DEVELOPMENT OF USERS' MANUALS
• EFFECTS OF LATERAL SEPARATION BETWEEN DOUBLE CENTER-STRIPE PAVEMENT MARKINGS ON VISIBILITY UNDER NIGHTTIME DRIVING CONDITIONS
• EFFECTS OF PAVEMENT MARKINGS ON DRIVER BEHAVIOR AT FREEWAY LANE DROP EXITS
• EMPIRICAL ANALYSIS OF TRAFFIC CHARACTERISTICS AT TWO-WAY STOP-CONTROLLED INTERSECTIONS IN ALASKA
• EVALUATION OF ACCURACY OF U.S. DOT RAIL-HIGHWAY GRADE CROSSING ACCIDENT PREDICTION MODELS
• EVALUATION OF PROPOSED MINIMUM RETROREFLECTIVITY REQUIREMENTS FOR TRAFFIC SIGNS
• EVALUATION OF STROBE LIGHTS IN RED LENS OF TRAFFIC SIGNALS
• HIGH-VOLUME PEDESTRIAN CROSSWALK TIME REQUIREMENTS
• KNOWLEDGE-BASED PERSONAL COMPUTER SOFTWARE PACKAGE FOR APPLYING AND PLACING CURVE DELINEATION DEVICES
• MOTORIST INTERPRETATION OF YELLOW X AND YELLOW DIAGONAL ARROW IN FREEWAY LANE CONTROL SIGNAL ARRAY
• TRAFFIC SIGN READING DISTANCES AND TIMES DURING NIGHT DRIVING
• VISIBILITY OF NEW PAVEMENT MARKINGS AT NIGHT UNDER LOW-BEAM ILLUMINATION
• VISIBILITY OF NEW YELLOW CENTER STRIPES AS A FUNCTION OF OBLITERATION
• YELLOW PAVEMENT MARKINGS WITH YELLOW NIGHTTIME COLOR