Because data on truck movements of specific hazardous chemicals are not available, methods for estimating them are needed. One possible method of collecting data is through surveying or reporting movements by truckers or shippers. A less costly alternative is to use secondary data on production and consumption of chemicals to identify the chemicals that are moving, the probable origin-destination pairs of these movements, and the probable routes taken. An approach that relies chiefly on secondary data is developed. The basic data on production and consumption came from available data bases on chemicals and chemical producers in the United States. These data were usedto determine the chemicals that account for at least 80 percent by volume of hazardous chemicals moving by truck in the United States and to identify major producers and consumers of each chemical. Through interviews with these producers and consumers, rules were developed for estimating the modal split among truck, rail, and water transport on a chemical-by-chemical basis. A gravity model was applied toestimate the origin-destination pairs and routes for truck shipments. A description of the approach and the results of its application to three large-volume hazardous chemicals are presented.
Samenvatting