Browsing by Author "Bandara, Saman"

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item: Conference-Full-text
Development of walking trip rates for different land uses
Hewawasam, Chamali; Bandara, Saman; Wirasinghe, SC
This paper aims to develop walking trip rates for different land uses in an urban area. Walking trip rates are developed for six identified land use categories, namely residential, commercial, institutional, recreational, transportation and religious. In conventional modeling processes, the number of trips made by a household is modeled in terms of household size, income, and other socio demographic variables; any effect of location, land use, or transportation service level is discounted. However, trip rates must vary with accessibility and some empirical studies have found that they do. In light of conflicting empirical results, and the obvious need for more truthful and policy-sensitive travel forecasts, this issue is revisited. It was found out from the literature that while methods for finding trip rates for motor vehicles are well established, there are not many established procedures for measuring and predicting trip rates for non-motorized trips, though some researchers have found trip rates for selected land uses, for households in particular. The independent effects of land use and accessibility variables on household trip rates are tested using data from house hold travel surveys and trip diaries. To collect data on travel behavior of the dwellers, household travel surveys and trip diaries were used. After developing the household travel survey form and trip diary form, a pilot study was carried out to finalize the survey forms. By analyzing these data along with road side surveys, trip rates were identified for the selected land uses. This is a unique attempt to develop walking trip rates for different types of land uses.
item: Conference-Full-text
New methodology for developing driving cycle(s) for Sri Lanka; case study, Colombo, Sri lanka
Galgamuwa, Uditha; Perera, Loshaka; Bandara, Saman
Even though driving cycles have been adopted around the world in different type of applications, the data needed for each steps is costly and time consuming. Majority of the Developing countries do not have systematic data bases for traffic related information such as origin-destinations, vehicle kilometers, average annual daily traffic etc. for majority of road links. Meager amount of available data is not sufficient to develop a driving cycle. Even though the data is collected, significant effort has to be made to construct a driving cycle that closely matches to the population data set. This paper gives simplified methodology for developing driving cycles using different approaches for route selection, data collection and cycle construction. For the route selection the available methods have been combined together and modified to suit for developing countries where no details traffic flow information will be available. Also a method was adopted for data collection by dividing selected routes in to links and grouped them according to daily traffic to optimize the cost for data collection. Road links were divided using physical junctions on the road and routes were selected using traffic generators and attracters combined with Origin Destination data. Also methodology was developed for synthesize data population using collected data from road links. Another issue for cycle construction is to construct a cycle which is close to population parameters. Using existing methods many cycles have to be constructed until the acceptable cycles is generated. New methodology has been adopted to develop driving cycle to match the population parameters and then to select data for driving cycle using Markov chain. As a case study Colombo, Sri Lanka has selected to apply the new approach of driving cycle construction for developing countries.
item: Conference-Full-text
Prioritizing transport infrastructure projects at early stages of projects
Gamalath, Isuru; Perera, Loshaka; Bandara, Saman
Investment on transport infrastructure is a significant component in a country’s budget as it is identified as a key factor to facilitate the country’s development. At the same time demand for transportation is positively correlated with the development. With this increasing demand for transport infrastructure and limited funding available, it is necessary to prioritise appropriate projects. Current appraisal practices at the early stages of projects fail to identify some important criterions and therefore, may ultimately end up not selecting the most appropriate project(s) which addresses contemporary concerns. Therefore the objective of this study is to identify a cost effective method and factors that should be considered in evaluating alternatives at the early stages of transport infrastructure projects. Both academic and grey literature was reviewed to identify current practises; methodologies and factors concerned in the recent past. Most of the time feasibility reports used descriptive format and often gave vague conclusions. Therefore the final selection of alternative(s) is implicit. A performance matrix was developed in this study based on multi criteria analysis linear additive model. This method was primarily selected as it is easy to use in practise. In addition to the traditional criterions, this matrix contains new criterions that should be looked into with the current interests. A case study for Kandy expressway alternative selection based on this developed performance matrix is presented in this paper. In addition to the new matrix, a modified scoring system was used in the analysis to minimise the variations, as scores are given by different experts. Further, analysis was compared with the view of different experts and results of sensitivity analysis to address the possible arguments on weight given to each criterion.