Over the last decade significant developments in the field of Intelligent Transport Systems (ITS) have emerged as innovative tools have been developed based on the application of Information and Communications Technologies (ICT) in the transport sector. There is agreement in the transport research and practice communities that the main functions of ITS and related services include increasing efficiency in transport, improving traffic safety, increasing transport comfort and improving environmental performance of transport. However, it is widely acknowledged that deployment of ITS services is fragmented and slow, as there are several barriers hampering successful implementation of these services. They range from technical barriers (e.g. lack of interoperability of services) to institutional (e.g. lack of robust legislative framework), economic (e.g. high investment costs) and social/organisational (e.g. lack of cooperation between stakeholders) ones. Furthermore, a set of ITS service performance measures which can be widely accepted by all relevant stakeholders is still required. As part of a wider research initiative, this research builds on the need for a better understanding of the barriers hampering ITS services deployment and the set of Key Performance Indicators (KPIs) currently used for ITS services. The main objective is to identify the main barriers and KPIs for both different market segments and types of ITS services, based on a systematic review of the relevant literature, complemented by a series of interviews with participants from a number of ITS service initiatives. This research makes a significant contribution to the existing body of knowledge on barriers hampering ITS service deployment and measuring success of ITS services. In doing so, it helps transport research and practice in their efforts to develop and deploy service initiatives that successfully meet the expectations of their key stakeholders.