Converting traditional barrier-type toll facilities to open road tolling has the potential to dramatically increase the flow rate of a given road. However, the process of transforming a barrier-type system into a free flow toll road presents a number of operational challenges for decision makers. In this paper, we use a simulation model of toll plaza flow to measure the impact of such a conversion on capacity and queuing. We find that the process of conversion is complex and has the potential to undermine many of the flow improvements that are inherent in electronic toll collection.