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Abstract
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Local roads are designed based on technical requirements determined by the assumed design speeds. However, the actual speeds of vehicles on these roads are usually significantly greater.
RESULTS of the research conducted by the authors show that the differences are as large as 20 - 40 km/h. Inconsistency of geometric solutions of the roads with actual speeds causes presence of accidents at sections with the greatest differences between the design and actual speed.
The abovementioned circumstances led to undertaking of research which aimed at the following:•
Assessment of geometric solutions' influence on speed on roads with low design speed;
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Speed change assessment on road sections with large differences between the design and actual speeds using speed as a surrogate road safety measure;
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Analysis of the need to change the current practice of assuming the value of the speed for the design, based on empirical data and speed prediction models.
As a result of the research, recommendations for selection of speed for the design with respect to road function have been developed, in lieu of currently used values of design speed. The range of applied speeds for the design at local roads was limited to 60 - 70 km/h. Cases in which local speed limits are necessary have also been shown.
Language: en |