Determinants of Variability in Preliminary Engineering Funding

Abstract

Preliminary engineering (PE) is a phase in the Virginia Department of Transportation (DOT) project development process. PE funds support tasks such as planning or environmental studies, design, and public involvement. This study analyzed variability in the Virginia DOT's program-level PE expenditures [i.e., aggregate funds from all projects, completed or not, that were spent on PE as opposed to right-of-way (ROW) or construction, based on FY 2004 to 2012 data]. Although the mean percentage of total funds (PE + ROW + construction) spent on PE statewide from 2004 to 2012 was 14.7%, the mean annual district PE percentage for the Virginia DOT's nine construction districts ranged from 11.3% to 21.3%. Three statistically significant variables explained most (89%) of this variation: (a) percentage of expenditures for minimum-plan or no-plan projects (i.e., projects that use a design template), (b) percentage of expenditures each year for large projects, and (c) percentage of projects in the development phase (i.e., projects for which PE or ROW but not construction funds had been spent). Although the first and second variables showed that PE percentage reflected project attributes, the third variable suggested that PE percentage partly reflected a programming decision (i.e., the amount that should be invested in preparing projects for future construction versus building prepared projects). The model that explained district-level variation in PE percentage suggested that although the programming decision could affect it by as much as 8%, project attributes could influence PE by as much as 11%. Thus, programming decision and project attributes both affect PE percentage.