Cash Flow Control of New Jersey Interstate Needs

Abstract

In 2002, a study assessed the structural condition of New Jersey's Interstate network and determined its rehabilitation needs for the next 30 years. Deflection testing was performed on approximately 750 testing miles, and cores and bores were also taken. In addition, a ground penetration radar survey and a limited visual inspection were carried out on the entire length of the Interstate network, including the associated ramps. The data were collected to complement the data available in the Capital Program Management State Pavement Management System, such as the International Roughness Index data, which the state collects every 2 years. In addition to field testing, traffic and cost data were gathered from existing sources within the New Jersey Department of Transportation (NJDOT) and used in the rehabilitation analysis. Furthermore, by NJDOT's request, the cost of reconstructing all inside and outside shoulders to the same structural capacity as the traffic lanes was estimated. The results of the study indicated that major spending would be required in the first few years of the analysis period, followed by less spending in subsequent years. However, NJDOT's desired cash flow pattern involved beginning with lower levels of funding and then increasing spending in latter years. As a consequence, additional analyses were run to consider whether intermediate treatments could be performed in order to meet this desired cash flow. This paper presents an overview of the Interstate Rehabilitation Needs Study along with a discussion about how the desired cash flow was achieved.