ICAHETS - 2011

Permanent URI for this collectionhttp://192.248.9.226/handle/123/19001

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Browsing ICAHETS - 2011 by Author "Bandara, JMSJ"

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    item: Conference-Abstract
    Accommodating road accident records in a comprehensive highway management system
    (Department of Civil Engineering, 2011-07) Bandara, JMSJ; Silva, SA; Rajapaksha, RPGKS; Pasindu, HR
    It has become important to improve planning, design, construction, operation and maintenance standards and manage road system efficiently. There are number of management systems such as pavement management system, road inventory systems, accident data recording system, traffic and passenger demand models, traffic assignment models have been established to handle different stages of road transport. As different organizations are responsible for the above different processes it is imperative to have these systems coordinated to have an integrated highway management system that will share information, expectations and experience. Today road accidents have become a significant negative impact to all road users. To reduce the number of accidents, it is important that manage the accident data in systematic manner because it will provides lot of information. This data is very important to traffic and highway engineers because it helps them to identify the unsafe location of the roads and the reasons for that. This is essential in road improvement projects to carry out safety audits and find the solution to minimize the number of accidents. This paper presents how a road inventory and accident data system could be integrated to share information from one another. In addition the paper highlight how road inventory data and accident data can be used to analyze accidents at road link, road type or administrative area vise and identify accident prone locations or reasons for different types of accidents. The programme was written using VBA (Visual Basic for Applications) which is more relevant to customize ArcGIS Desktop Applications to store the data in a Microsoft access database and filter the database using the developed VBA interface. For example, users can find out the number of accidents on a location according to various crash factors contributing to the accident from human side, vehicle side and road environment side. According to filtering combinations, model is developed to show the number of persons died, injured and detail list of accidents. The model has capability to connect road inventory data and accident data with attribute tables in ArcGIS. Therefore, engineers can directly use the GIS tools to represent and analyze the above data in an efficient manner.
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    item: Conference-Abstract
    Pedestrian facilities in urban environments using "walkability" measures
    (Department of Civil Engineering, 2011-07) Dias, I; Bandara, JMSJ; Pasindu, HR
    Pedestrian facilities in urban environment are sometimes less appealing in residential/ recreational areas or insufficient to serve the peak hour pedestrian flows in commercial areas .There is no proper mechanism to evaluate the deficiencies in pedestrian facilities. Furthermore, increasing trend in motor vehicle use and pedestrian related accidents are the evidence of inadequate facilities for pedestrians. This research proposes a scoring model to evaluate pedestrian facilities in urban environment using "Walkability" measures. Walkability is an idea of quantifying the safety and desirability of walking routes. The model can be used to evaluate pedestrian facilities in road links to compare different road links or to identify deficiencies in a given road. At present walkability is evaluated using qualitative measures that are very subjective. Existing methods of evaluating walkability was carefully studied and the limitations and weaknesses were identified. Methods to evaluate as many features were proposed and validated. Among these factors, several features of sidewalks such as width, elevation difference, paving type and continuity are assessed. Modal conflict, the conflict between pedestrians and bicycles/ motorized vehicles is measured using passing and meeting number of events. Availability of crosswalks and delay at un-signalized and signalized crosswalks are some of the parameters used to evaluate crossing facility. A good mix of land use where the number of destinations (Groceries, restaurants, schools, health facilities, Cinemas, etc.) is higher is considered to be a good walkable neighborhood. Availability of pedestrian facilities including, benches, shades, bus halts with seats, pedestrian information boards, proper street lighting add scores to a road link. Addressing differently able people; the blind, the disabled, push carts, children is also taken in to consideration while universal accessibility is believed to be at vital importance. Apart from the above quantitative measures, parameters such as, aesthetics is also assessed qualitatively. A score as a percentage is finally obtained from the evaluation where 100% means a perfect road to walk and 0% means a disasterfor walking.
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    item: Conference-Abstract
    A revisited model estimation for international passenger demand at Bandaranaike international airport, Sri Lanka
    (Department of Civil Engineering, 2011-07) Piyathilake, LWD; Priyadarshani, GAC; Bandara, JMSJ; Pasindu, HR
    Regression models are quite commonly used in air travel demand estimation. This paper presents a passenger forecast model for the Bandaranaike International Airport, which is the single international gateway for passengers travelling in and out of Sri Lanka at the time of conducting the study. The study hypothesize that the parameter estimates for the demand determinants of air travel in Sri Lanka has changed overtime and the model estimation revisit the analysis carried out by Bandara and Wirasinghe (2001) to estimate passenger demand for medium sized airports. Post fact analysis of the model proposed by Bandara and Wirasinghe (2001), revealed statistically significant differences between prediction and actual values with outliers to the 95% confidence interval bands established for the regression model. The deviations were results of the effects of 9/11 incident and heightened civil unrest experienced time to time in Sri Lanka during the past ten years. An empirical validation to the existing model was identified as necessary, since Sri Lanka is at the juncture of post war development proposals to promote the country as an aviation hub. A further objective of estimation was to justify the best time scale of past data to be used in model calibration for passenger demand forecasting using econometric models. The new estimates are established using a multiple regression model with two variables; Real Gross Domestic Product (RGDP) and a Dummy (TJ variable for severe terrorism/civil unrest conditions. Findings of the previous study is revalidated empirically by concluding that using 12-15 year past data for model calibration meets multiple regression assumptions at its best with time series data, avoiding spurious regression. The results suggest that the model forecasts ideally fits with the actual in the medium term. Hence, updating the model on a roll-out basis increases the validity of the model estimates.