Conceptual Framework for Understanding Latent Demand: Accounting for Unrealized Activities and Travel

Historically, latent demand—the activities and travel that are desired but unrealized because of constraints—has been examined from the standpoint of understanding the effects of proposed capacity or service improvements on travel demand. Drawing on work from a variety of theoretical perspectives, this paper presents a broader conceptual view of latent demand that provides a useful framework for researching and understanding these unmet needs. This view is important from an equity standpoint, as it provides insights into questions of transport disadvantage, social exclusion, and poverty. The framework presented here is theoretical in nature and untested empirically. This paper aims to promote discussion and ultimately a more developed theory that can inform transportation planning and forecasting. A better definition and quantification of latent (or induced) demand can aid transportation planners in better predicting the effects of future transportation investments and other social, economic, and technological changes.