While the results of such studies will vary widely, due to the very wide range of traffic flows on different roads, this site was chosen due to the appropriate level of construction and traffic flow data available at a location representative of many similar roads.
Zapata and Gambatese, 2005 ).
In this study, micro-simulation modelling of traffic was used to estimate emissions caused by delays at road works, for several traffic management options.
The emissions were compared to those created by the maintenance operation, estimated using an LCA model.Chen., 2010 ; Sayagh., 2010 ; Huang., 2013 and comparison of design options (.Case study and LCA model System boundary The case study site is located in Lincolnshire on the A17 between Sutton Bridge and Kings Lynn, an inter-urban road in the UK Midlands; with length 720 m including 200 m dual (22 m width) and 520 m single (11 m width) carriageway.Mroueh., 2001 ; Birgisdóttir., 2006 a growing practice in response to stakeholder calls for sustainable construction.Some previous studies have attempted this but have been limited to hypothetical scenarios or simplified traffic modelling, with no validation or sensitivity analysis.Marceau., 2007 ; eurobitume, 2011 compared to early studies of energy consumption only (.The life cycle inventory of pavement materials has been researched thoroughly by material associations (.However, they are generally close to, or above, the materiality threshold recommended in PAS2050 for estimating carbon footprints, and reach 510 when traffic flow levels are increased (hypothetically) or when traffic management is imposed outside times of lowest traffic flow.Because vehicle fuel consumption is largely determined by many factors other than pavement performance ( Hammarstrom., 2009 ; Lepert and Brillet, 2009 traffic emissions are typically excluded from pavement LCA.Assumptions are made on the distance of transport and payload of the trucks.Cross., 2011 ; Santero., 2011a ).Explored impact of extending system boundary of road pavement LCA to include road works traffic delays.Hakkinen and Makela, 1996 ; Stripple, 2001 ).Asphalt production followed the cut-off method for end-of-life (EOL) scenario, 2 in compliance with a UK public specification manual de revit structure pdf for measuring greenhouse gas emissions of products ( BSI, 2011 ).Keywords, life cycle assessment; System boundary expansion; Road works; Microsimulation; Pollutant emissions; Sensitivity analysis, introduction, the life cycle assessment (LCA) of road pavements has been developing since the 1990s (.More recent LCA research is focused on the methodological choices, for instance allocation (.
The system boundary of the pavement construction and maintenance LCA is illustrated in Fig.
New asphalt and milled recycled asphalt pavement (RAP) are transported for 80 km to site and stockpile, respectively, using 2028 t truck.
Blast furnace slag (BFS a by-product from the iron making process, was used as aggregates in DBM base (200 mm thick) and binder (60 mm thick) courses, and as coarse aggregates ( 2 mm) in HRA surface course (40 mm thick).A few studies have investigated the additional emissions, but have been limited to simplified traffic modelling ( Huang., 2009a ) or hypothetical scenarios ( Santero., 2011b with no validation or sensitivity check on the traffic flow or traffic management (TM) options.No processing energy and emissions were allocated to BFS before transport to the asphalt plant.The pavement consisted of 40 mm surface course, 60 mm binder course and 200 mm base, all courses being made with bitumen bound materials (asphalt).The work is strengthened by including recycled and secondary materials (.It is recommended, therefore, that emissions due to traffic disruption at road works should be included within the system boundary of road pavement LCA and carbon footprint studies and should be considered in developing guidelines for environmental product declarations of road pavement maintenance products and.The proportion has been quantified by recent European research to be in the range of 9399 ( ecrpd, 2010 ) or even higher ( Milachowski., 2011 ).It has been noted in the earliest of LCA research that traffic emissions in the use phase can account for the majority of emissions in the pavement life cycle ( Piantanakulchai., 1999 ; Highways Agency, 2003 ).Quarry aggregates and BFS are transported for 50 km, and bitumen for 200 km, to the mixing plant using 2028 t truck.The impact of the above allocation methods on the LCA results has been reported ( Spray., 2012 ) and thus was not investigated in this study.This paper uses a case study of a UK inter-urban road, to explore the impact of extending the system boundary of road pavement life cycle assessment (LCA) to include increased traffic emissions due to delays during maintenance.
Emissions from traffic disruption found close to or above the 1 materiality threshold.