This study focuses on incorporating the travel attributes (time, cost, and availability of modes) in the activity planning time horizon analysis and presents mixed logit models estimated separately for different activity groups. Although the effects of many other variables are estimated, the focus is on the effects of location (in-home versus out-of-home) and log-sum (measure of travel characteristics) variables. The inclusion of several other variables (household and individual characteristics and activity attributes) allows controlling for many factors affecting this choice and increases the explanatory power of the models. The results of the models reveal that the effects of location and travel characteristics on planning time horizon choice vary among different activity types. Toward a better understanding and quantification of the effects of location and travel attributes, the probabilities of planning the activities in different time horizons are estimated separately for in-home and out-of-home, and with an incremental increase in the logsum. Results reveal that the household obligations and active activities are very sensitive to travel characteristics; therefore, significant changes in the planning and execution of these activities may be expected with changes in the transportation system characteristics. The results of this study enhance the understanding of relationships between travel time, cost, availability of transportation modes, and the activity planning process.