Road safety: speed reduction as a road safety measure

Abstract

The growing number of road accidents is a major national problem in Sri Lanka. By analyzing the police database of past accident records, the excessive speed has been identified as a prominent cause for road traffic accidents. According to the past accident records from the year 1992 to 1999, there were about 17507 fatal accidents, and 29526 grievous accidents occurred out of the total of 613785 accidents. The annual loss due to road traffic accidents has been evaluated as Rs. 12.9 billion in the year 1999. The analysis of past accident records, has shown that there are about 48% of speed related fatal accidents, 45% of speed related grievous accidents and 43% of speed related non grievous accidents, 37% for damage only accidents out of total road accidents. This clearly implies that there should be some techniques to bring down the speeds at high accidents prone locations. There are various methods such as speed humps, rumble strips, transverse bars, cushions and plateau adopted as speed reduction measures all over the world. Based on the literature study done on speed reduction measures adopted in other countries, transverse bar marking system has been selected to study in detail in the Sri Lanka context. This research was focused on high speeds at intersections since a higher percentage of accidents occurred close to or at the intersections. A feasibility study has been conducted for a speed reduction measure which uses transverse bar markings. The results before the study and after the study indicated that there is a marginal drop in the speeds due to the presence of transverse strips for most of the vehicle types. Thus, the use of a combination of transverse strips and other measures is suggested at intersections..