State College Eastern Inner Loop Design Project

Overview

Transportation agencies have discussed an Eastern Inner Loop roadway concept that is formed by a network of roads for decades: University Drive, Park Ave, North Atherton, Blue Course Dr, Vairo Blvd, and Mount Nittany Expressway. Environmental impacts and traffic control issues provide bounds for this project. Three design alignments must be analyzed/estimated in accordance with the AASHTO Green Book while also minimizing costs, travel time, crashes, and impacts to residential/commercial properties, wetlands, and the existing environment.

Objectives

Our team of civil engineers have developed a series of design alternatives, a performance-based evaluation of each alternative, and AutoCAD/Civil 3D plots(plan, profile, cross-section) to complete the Eastern Inner Loop concept.

Approach

-Identify functional classifications of the alignments to optimize traffic control related conditions

-Produce a detailed design description that includes controls/criteria for the proposed alignments

-Use Civil 3D to plot horizontal & vertical alignments

-Analyze three alignments based upon environmental impacts

-Use Highway Capacity Software (HCS) to determine LOS, volumes, and other traffic controls

-Determine design superelevations for the preferred alignment

-Ensure travel speed is consistent with design for three alignments

-Quantify the number of crashes along alignments & intersections

-Create a preliminary cost estimate of preferred alignment

-Plot typical cross-sections (normal crown and superelevation) & intersection design in AutoCAD

-Produce a final cost estimate (addition of technical pavement design)

-Use Redbook Wizard to produce a user benefit analysis

-Conclude and summarize a final preferred alternative

Outcomes

-Net benefits of Vairo Blvd total in ~ $921 million over its projected lifetime.

-The benefit to cost ratio was nearly 89 to 1 and would cost the community very little in operation and construction delays.

-Major costs and for the project would come from overall construction and minor costs regarding management, planning, and design.

-Over a 20 year projected lifetime, the Vario Boulevard East Inner Loop alignment would save the community close to $1 Billion and cost less than $50 Million.