iBus is a ‚£117m Automatic Vehicle Location (AVL) and radio system that aims to help London Bus Service Limited (LBSL) to run a more reliable, consistent, bus service. The first installations took place in March 2007, with completion in April 2009. It is important that the intended benefits of iBus are tracked throughout rollout and after the lifecycle of the project in order to realize their full potential and provide value for money. The benefits realization workstream was set up with this aim and is focused on identifying and tracking all the potential benefits across the iBus project, in particular those on which the business case was predicated (service reliability improvements and the value to passengers of On-Bus Next Stop Signs). This paper outlines a number of key potential benefits that have been identified and are currently being monitored by LBSL, and some of the analytical challenges that will need to be overcome to ensure successful tracking. Much of the work to date has focused on understanding and monitoring system performance. Ensuring that system Key Performance Indicators are consistently met should result in measured passenger benefits straight away. Focus can then shift to the business benefits that are expected through effective utilization of a new performance zreporting regime, service control facility and radio system. Benefits realization is a recognized discipline within Program Management. ¢â‚¬ËœBenefits' are referred to throughout the paper in order to describe the potential improvements that stakeholders might experience as a result of iBus implementation. The paper discusses some of the work that is currently being done to measure these potential benefits and understand areas for improvement.