AbstractAs rail transit systems are becoming more complex, from a hardware, software and technology standpoint, new approaches are being contemplated to reduce capital project risk. Systems integration has come forward as a way to efficiently transition from traditional systems designed and installed independently without the need for a formal, structured process for physical, functional, logical, and operational integration, to more integrated systems. This paper presents the application of systems integration as a way to mitigate risk on two light rail projects in New Jersey, USA. It discusses how and at what levels various and complex interfaces were managed, and presents methods used to ensure that interface gaps were avoided, duplication reduced, conflicting requirements across projects negotiated and managed, and coordination among all stakeholders refined. It also highlights similarities and differences in approaching the systems integration process for these two projects, the unique challenges faced by the project teams, and general lessons learned that can be carried forward on other capital projects.