This study of automotive transaction relationships in the U.S.A. and Japan offers data which indicate that transaction costs do not necessarily increase with an increase in relationship-specific investments. We empirically examine the conditions under which transactors can simultaneously achieve the twin benefits of high asset specificity and low transaction costs. This is possible because the different safeguards which can be employed to control opportunism have different set-up costs and result in different transaction costs over different time horizons. We examine in detail the practices of Japanese firms which result in effective interfirm collaboration.