Showing 3 results for Free Flow
Masoud Ghodsian ,
Volume 2, Issue 1 (3-2004)
Abstract
The flow characteristics of triangular weir are studied under free and submerged flow condition. This paper reports the results of an investigation carried out to establish the stage-discharge relationship for sharp and broad crested triangular weir. The stage-discharge relationships are deduced by the application of the theorem of the dimensional analysis and the incomplete self-similarity theory coupled with experimental data.
Dr. Ashish Dhamaniya,
Volume 15, Issue 7 (10-2017)
Abstract
The present study demonstrates the influence of operating speed on capacity of a midblock section of urban road. Speed – flow data collected at 12 midblock sections of 6-lane and 4-lane divided urban arterials in four metropolitan cities of India are analyzed to determine their capacity. Lane capacity was found to vary from 1482 pcu/hr to 2105 pcu/hr. This variation is explained on the basis of city size and driving behavior, which would influence the free flow speed on the road. Free flow speed was also measured at each section and these speed data were used to determine operating speed (85th percentile of free flow speed of standard car) on the road. Lane capacity was found to be strongly related with operating speed on a road and a second degree polynomial model is developed between the lane capacity and operating speed. This model is further validated by collecting speed flow data at two new sections and their capacity was estimated from field data and from the model developed in the study. The predicted capacity was found to be matching with field capacity and the maximum error was 0.10 percent. Operating speed on a road can vary due to road surface condition, side friction or similar other factors. All these will have influence on capacity of the road. The capacity model suggested in the present study can be a useful tool to determine capacity of an urban road from its operating speed data.
Dr. Prasanta Bhuyan, Mr. Amit Das,
Volume 15, Issue 7 (10-2017)
Abstract
The present study aims at the divination of the speed ranges of Level of Service (LOS) categories of urban traffic facilities. Free flow speed (FFS), congested travel speed, geometric and surrounding environmental conditions are considered to define LOS criteria for urban street in Indian context. Cluster analysis is found to be a powerful tool to delineate LOS criteria. Hard Competitive Learning (hardcl) method is used to classify large number of speed data obtained using Global Positioning System (GPS). Six cluster validation parameters are used to classify the urban streets as well as the LOS categories. It can be confirmed from the above research work that the LOS categories for different urban street class are lower than that of the values proposed by HCM 2000 and the average travel speed of LOS categories expressed in percentage of the free flow speed are lower than the values mentioned in HCM 2010.
