One of the main objectives of COST Action TU 1406 is to build a performance indicator database, in order to develop technical recommendations which will specify the performance goals, aiming to provide a methodology with detailed step-by-step explanations for establishment of QC plans for different bridge types. This paper presents the main findings of Working Group 1: Performance Indicators (PI), based on analysis of documents related to bridge maintenance, assessment and management from different European countries through surveying, clustering, homogenization and categorization. In addition, further steps in order to correlate with the objectives of the Working Group 2, whose work is dedicated to revealing Performance Goals (PG), and the Working Group 3, dedicated to the establishment of Quality Control (QC) plans, if is foreseen.