SIKTSTRAECKA I HALVLJUS TILL HINDER PA TORRA VAEGBANOR AV VARIERANDE LJUSHET (LOW BEAM VISIBILITY DISTANCES TO OBSTACLES AS A FUNCTION OF DEGREE OF RETROREFLECTIVITY OF DRY ROAD SURFACES)
Bad visibility of obstacles in low beam has remained an unsolved problem for the driver at night. Several measures have been taken to improve this situation. These measures have up to now, mainly been concerned with improvements of the headlights. Consequently other important parameters have been insufficiently studied. The retroreflectivity of the road surface is one such parameter. In this work the significance of the retroreflectivity of dry road surfaces upon visibility distances to obstacles on the road has been studied. The purpose has been to relate visibility distances to retroreflectivity of the road surface and if possible to set an interval of retroreflectivity in which the visibility distance to obstacles on the road is maximized; and to validate a model for prediction of visibility distances to obstacles on the road. The consequences of the empirical results valid for dry road surfaces, which have been presented here, are that the reflection properties of wet road surfaces have become the main interest for future research in order to improve the visual conditions of the driver at night. Beside a larger variation in retroreflectivity compared with dry road surfaces, wet road surfaces vary enormously in specular reflection.
- Text in Swedish; abstract and summary in Swedish and English. Also pub. as ISSN-0347-6030.
Swedish National Road and Transport Research Institute (VTI)Olaus Magnus vaeg 35
Linkoeping, Sweden SE-581 95
- HELMERS, G
- YTTERBOM, U
- Publication Date: 1980
- Pagination: 45 p.
- TRT Terms: Brightness; Mathematical models; Pavements; Reflectivity; Roads; Texture; Visibility
- Subject Areas: Highways; Pavements;
- Accession Number: 00329158
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: VTI-202
- Files: NTIS
- Created Date: Jun 12 1981 12:00AM