Pipelines represent a linear risk source that can create unique challenges when assessing risks. In the past, risk has been managed by identifying construction requirements and setbacks based on population densities and types of land use. In the current risk assessment a matrix-based approach has been developed so as to determine the risks associated with high-vapor pressure liquids pipelines. The approach involved the development of a matrix representing each 100 m section of the reviewed pipeline along with approximately 30 risk factors that describe that section of the pipeline. Further, a receptor matrix was constructed to account for each hectare of land within 1 km of the reviewed pipeline system. This approach has allowed for the determination of risk as a function of location and separation from the pipeline and in turn has allowed for the determination of those areas where peak risks exist. In addition, this approach has ensured that the linear geometry related to pipeline risks has been accurately modeled. The resulting estimated risks have been evaluated against MIACC risk thresholds (geographic risk-based measures) and against proprietary internal corporate standards (societal risk-based measures). In this way the acceptability of the risk from the perspective of both the potentially impacted community and that of the pipeline operator can be measured. The net result is that the company has a clear picture of the risks associated with its pipeline and is better able to optimize its risk management and pipeline integrity programs. (C) 2005 Elsevier Ltd. All rights reserved.