Multiattribute decision analysis of mandatory ballast water treatment measures in the US Great Lakes

Mandatory ballast water management, resulting in an increase of required freight rates on the St. Lawrence Seaway, could induce a modal shift away from marine transportation. Such a shift may cause such side effects as increased air pollution and lower transportation safety. A multinomial logit model is built to predict the changes in market shares of competing transportation modes. Two wheat transportation scenarios are studied. The results show that only a small shift, if at any, will accompany mandatory measures for ballast water treatment. To evaluate the trade-offs between the side effects brought by any modal shifts and the NIS invasion effects, the analytic hierarchy process is used to analyze the preferences of federal and state decision-makers. Analysis of questionnaires shows that among the three alternatives, ballast water exchange, filtration/UV, and heat, ballast water exchange proved to be the favored method.