Quantifying impact factors of sustainable road planning in Taiwan

This research aims to identify both cost and benefit impact factors using quantitative techniques, and then to determine their corresponding weights for sustainable road engineering projects. The impact factors were initially gathered from literature review and expert interviews, resulting in a total of 10 factors for questionnaire development. A 5-scale Likert questionnaire was accordingly developed for a survey. Of the 120 questionnaires distributed to randomly selected practitioners in the Taiwan construction industry, 54 were returned for fulfillment of the statistical criteria. A reliability test was employed to examine sampling adequacy in the beginning stage of data analysis. Factor analysis was used to identify the impact factors. The weight of each factor was determined using principle component analysis combined with orthogonal rotation. The analysis shows nine factors categorized into three components of the cost aspect and six factors categorized into two components of the benefit aspect. Of both cost and benefit aspects, the "construction" component has the highest weights but contains slightly different factors. This indicates that the practical cost of using designs beneficial for sustainable road engineering may be high. Focusing on environmental concerns may be costly and provide limited benefits to the public.