The relative risks of hazardous material spills in the 13-km-wide Abegweit Passage between Prince Edward Island and mainland Canada are analyzed, and counteractive measures are discussed for an existing ferry crossing and an alternative link by a bridge. The spills can originate from trucks hauling dangerous goods on board ferries or over the bridge, ships involved in collisions with the ferries or instrikings of the bridge piers, and ferry or bridge maintenance operations. A methodology is developed for the analysis of the marine spill risks associated with the vessel traffic stream crossing (a) a ferry route; and (b) a bridge line. Because study-specific data are available neither on spill sizes nor on the conditional probability of a release from a vessel or truck damaged in an accident, an upper bound of probabilities and sizes of spills is estimated. The analysis results represent current traffic volumes and makeup of dangerous goods shipments. They do not reflect possible effects of future legislative, technological, and operations management changes that will undoubtedly aim at preventing and countering the effects of spills. Bridge and waterborne emergency response, containment of spills in the bridge drainage system, and more stringent operating and maintenance procedures should reduce the volume of hazardous materials spilled into the water. (A)
Samenvatting