This paper explains the principles involved in the development of an MS Excel - based decision assistance tool for indirect left (ILT) intersections. this tool, termed Signalized Intersection Life Cycle Cost Analysis (SILCC), analyzes three types of ILT intersections; (i) MUt, (ii) CFl, and (iii) jughandles. SO far, no tools have been developed that are capable of analyzing ILT intersections while incorporating cost and benefit aspects. In contrast, SILCC is designed to incorporate cost and benefit aspects in the evaluation of ILT intersections. It is interfaced with the Highway Capacity Software (HCS) and hence can perform macro-level operational analysis. It considers delay, fuel consumption, and emissions as operational performance measures. It is capable of performing life cycle cost analysis (LCCA) and providing net present value (NPV) and benefit-to-cost ratio (B/C) as surrogate measures of performance. Planners can use NPV or B/C for decision support while deciding among several alternatives for economic and efficiently operating ILT intersections. Additionally, SILCC feature the flexibility to alter input values so that it can be used for multiple conditions and criteria. A case study of rual traffic volume conditions indication that a MUT intersection had the highest NPV of benefits for both new construction and retrofits. However, because the construction cost for MUT retrofits was high for the particular condition, an MUT intersection had the highest B/C for new construction an a jughandle had the highest B/C for retrofits.