This thesis is one of a very few researches that pay special attention on freight mode choice decisions in urban areas. The objectives of this study are: (1) to identify the key factors that explain commercial sectors' vehicular mode choice decisions; and (2) to compare the trip-based and tour-based approaches to find out whether the mode choice decisions are made based on the entire travel itineraries starting from and ending at the home base (i.e., tours) or individual journeys from a location to another (i.e., trips). The commercial vehicle travel itinerary data collected in the Denver metropolitan area is used for the analyses, which considered five mode alternatives, including autos, pickups, Sport Utility Vehicles (SUV), single-unit trucks, and multiple-unit trucks. The travel itineraries from survey were sorted to trip data and tour data separately. To quantify the relationship between mode choice decisions and the potential affecting factors, discrete choice modeling techniques were applied on both data sets. The modeling results indicate that urban freight mode choice decisions are made based on tours rather than trips. In addition, four types of attributes were found to have significant impacts, including: (1) tour attributes such as the tour travel time; (2) destination types visited along a tour; (3) types of cargoes delivered and picked up on a tour; and (4) company types. As the sensitivity analyses imply, the proposed models can be applied to evaluate freight management strategies such as the fleet combination strategy in the "Green Freight" initiative and cargo consolidation strategy in the European Commission's "SMARTFREIGHT" project.