Influence of Night Rainfall on Stopping Sight Distance on Dark Roadways

Ben-Edigbe J.E1, *
, Makinde O. O 1
1 Department of Civil Engineering, University of KwaZulu-Natal, Durban, South Africa

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 1718
Abstract HTML Views: 571
PDF Downloads: 116
Total Views/Downloads: 2405
Unique Statistics:

Full-Text HTML Views: 853
Abstract HTML Views: 303
PDF Downloads: 76
Total Views/Downloads: 1232

Creative Commons License
© 2020 J.E and O. O

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Civil Engineering, University of KwaZulu-Natal, Durban, South Africa; E-mail:



To investigate the influence of night rainfall on stopping sight distance on dark roadways.


This study fills the research gap in stopping sight distance by looking at night rainfall impact on stopping sight distance on dark roadways.


To determine stopping sight distance under night rainfall (light, moderate and heavy) on dark roadways and compare the results with stopping sight distance under dry night on dark roadways.


In a ‘with and without’ night rainfall impact studies, traffic volume, speed, vehicle type and rainfall data were collected at selected sites. All surveyed sites had rain gauge within the catchment area of about 1km. Rainfall intensity was divided into three groups (light, moderate, and heavy). Dry weather data were used as a control parameter.


Results show that the average SSD decrease attributed to light rainfall is 15.2m (14%), moderate rainfall 18.3m (16.8%), and heavy rainfall 21.2m (19.2%).


Based on the results and findings, it is correct to conclude that the effect of night rainfall on dark roadways stopping sight distance is somewhat aberrant. It is also correct to suggest that night rainfall on dark roadways will cause a decrease in perception distance travel delay, an increase in braking distance and stopping sight distance.

Keywords: Speed, Stopping sight distance, Rainy night, Perception distance, Braking distance, Dark roadways.