A naive implementation of a road pricing system will collect an enormous amount of personal location data. In this paper we present a sophisticated system that is privacy friendly, i.e. where the invoices contain aggregated pricing information and where only the driver has insight into all the underlying details. Enforcement based on spot checking is used to keep drivers honest, and to make the system fraud resistant. These spot checks are integrated in the system in a novel way that does not impair the privacy of the overall system, as is the case in systems previously proposed. Our solution can easily be applied to other privacy sensitive contexts such as smart metering and e-ticketing in public transport.