Construction Inhibitors of Alternative Intersections and Interchanges: Insights from Claims and Supplemental Agreements

This study provides an evaluation of the performance of alternative (AII) versus conventional (CII) intersection and interchange designs by examining claims and supplemental agreements. Claims and supplemental agreements are requests for more time or money due to changes or additional work that were not included in the initial contract, and they have the potential to negatively impact on the cost and schedule of these projects. Using North Carolina Department of Transportation (NCDOT) data, normalized for compensation and schedule, it compares claim and supplemental agreement frequency and identifies inhibitors that negatively impact the construction of AII and CII designs. The main inhibitors that were identified for AII designs are utility conflicts, construction sequencing, signals and signage, traffic control, and material estimate changes. Findings indicate CIIs incur more claims than AIIs, and recommendations are provided to aim to reduce claims and supplemental agreements and enhance project success.