This paper proposes a model that enables Department of Transportation (DOT) policy makers to quantify the expected volume of projects that will qualify for letting in their alternate design/alternate bid (ADAB) pavement bidding programs. Current guidance on alternate bidding recommends a fixed percentage as the life cycle cost (LCC) threshold criterion to determine whether pavement selection decisions should be made through ADAB bidding practices. The paper’s analysis shows that the fixed LCC threshold percentage approach may have considerable shortcomings. Instead, a dynamic threshold value is proposed that can subsequently be calibrated by agencies, based on the desired size of their ADAB programs. The paper argues that since the costs of equivalent pavement designs exhibit considerable variation due to various project and agency-level factors, agencies’ desired alternate bidding program levels can only be achieved by taking into account the variation of equivalent pavement type costs as opposed to the current blanket threshold percentage. The paper demonstrates with Kentucky Transportation Cabinet (KYTC) ADAB data that modelling this variability through a random distribution is not only a close representation of actual agency data, but it also distills those variables that drive a large share of the complexity in agency ADAB policy decisions. The paper’s primary contribution is the derivation of a direct mathematical relationship between equivalent design premiums, agencies’ threshold criteria, and alternate bidding program volumes that can be used by DOT policy makers to better manage their ADAB programs.