Sustainability and emissions from roadway construction and how highway design can influence emissions.
Sustainable Pavement Overview
Heather Dylla, Federal Highway Administration (FHWA)
Sustainable Highway Construction Practices
An Assessment of CO2 Emissions in the Road Infrastructure Sector Through a System Dynamics Approach
Angie Ruiz Robles, Universidad de Los Andes Facultad de IngenieriaShow Abstract
Jose Alberto Guevara Maldonado, Universidad de Los Andes Facultad de Ingenieria
The development of road infrastructure projects involves processes that consume large amounts of energy and non- renewable resources. These processes generate construction waste and release important quantities of greenhouse gases. Based on that, this paper seeks to evaluate the environmental impact of road construction and maintenance through comparing carbon emissions generated by traditional and sustainable techniques. By adopting a system dynamics approach, this study presents a simulation model capable of reproducing the deterioration processes of the road network and calculating the carbon emissions associated with pavement-related interventions. The model developed was applied to Chile’s road infrastructure sector and replicates the maintenance and rehabilitation processes of the Chilean highways through different scenarios. According to the results, if sustainable practices are incorporated, CO2 emissions can be reduced between 13% and 19% per year in the country under study. Conclusions indicate that employing sustainable practices in maintenance and rehabilitation activities produces greater benefits than including green alternatives focused exclusively on new construction efforts. The proposed model can be used as a tool to formulate sustainable policies in the infrastructure sector and opens the door to research avenues focused on green interventions for existing road networks worldwide.
The Effects of Pavement Condition on LCCA User Costs
Egemen Okte, University of Illinois, Urbana ChampaignShow Abstract
Imad Al-Qadi, University of Illinois, Urbana Champaign
Hasan Ozer, University of Illinois, Urbana Champaign
Life Cycle Cost Analysis (LCCA) is one of the well-established methods to determine the cost-effective alternative between different transportation infrastructure projects. Life-cycle cost of a roadway alternative consist of agency and user costs over an analysis period appropriately selected. Agency costs include initial construction costs and maintenance and rehabilitation costs incur within the analysis period. User costs incur when there is a work zone present and also during normal operating conditions. In traditional LCCA, adopted by many agencies around the United States, it is assumed that the difference in user cost between alternatives are mainly arising from work zone costs. These costs are mainly vehicle delay costs, vehicle operating costs during work zones, crash costs and emission costs. The costs that arise during normal operating conditions (mainly vehicle operating costs (VOC) ) are not dependent on project alternatives and thus it is traditionally considered to be negligible. This paper introduces a methodology to test the sensitivity of vehicle operating costs to roughness and texture profile quantitatively and evaluate its contribution to LCCA calculations. It was hypothesized that even the slight changes in surface profile between various alternatives may result in different user costs between the alternatives. A case study is presented to illustrate the effect of user costs of normal operating conditions on LCCA analysis results. Case study showed that vehicle operating costs that arise during normal operation may greatly affect the results of LCCA and should be considered, especially for low volume traffic projects.