Safety, Mobility, and Cost Benefits of Closing One Direction of the Interstate in Rural Areas During Construction Work

Abstract

With specific regard to interstates in the rural area, Indiana Department of Transportation (INDOT) has expressed a need for research that sheds light on this Maintenance of Traffic (MOT) issue so the agency [INDOT and the contractor] can make informed decisions regarding the crossover sections versus the closure in one direction with detour roads. A number of studies have investigated the advantages and disadvantages of various MOT strategies; however, there is no specific study that can help INDOT traffic engineers and design engineers make decisions by comparing direct and indirect benefits of crossovers and detours (full lane closures). This research examined the advantages and disadvantages of entirely closing one direction of traffic over traditional work zone techniques (such as partial lane closure through median crossover) from the perspectives of the agency, road users, and the community. In the case of full closure, the study (a) examined the alternative MOT strategies and best practices through an extensive literature review and survey of agencies (b) investigated risk, benefit, and costs associated with selected detour routes (c) validated the identified critical factors through case studies in Indiana and at other states, and (d) implemented best practices in an expected project to evaluate the safety, mobility, and cost benefits of closing one direction. Through the literature review and four case studies, eleven KPIs for MOT strategy developments were identified. This study prioritized these KPIs through the survey questionnaire. The top five KPIs are (1) safety, (2) mobility, (3) budget constraint, (4) project duration, (5) complexity of project sites. Based on these KPIs and other findings presented in Section 4.3.3, this study has proposed a comparison tool for predetermined MOT strategies in the form of a flow-chart. This tool is followed by the scores or weights associated with each KPI. These scores are normalized—i.e., the most important KPI which is safety, has the maximum weightage 1 and rest of the KPIs are weighed relatively. INDOT has a set of editable documents which are references for making MOT decisions. This proposed flow-chart tool will “walk” the INDOT team through the use of these spreadsheets corresponding to the identified KPIs through this study. It will be at the discretion of the INDOT team as to which KPIs are relevant to the situation at hand. Therefore, the flow-chart tool is flexible to incorporate the dynamic nature of MOT strategy selection.