Thesis: This dissertation is motivated by two areas of research that address the impact of trade barriers on economic outcomes: the relevance of transport-related costs and the role of non-tariff barriers, particularly preferential rules of origin and local content requirements. These barriers are the overarching theme of my dissertation, in which I examine and quantify their effects on intra- and international trade. In my first chapter, I contribute to the trade literature by quantifying the impact of mode-specific transport costs on intranational trade and highlighting differences in these trade barriers across transport modes and categories of goods – a finding that is also important in the context of international trade. In my second chapter, I show that government efforts originally intended to support international trade, such as through the negotiation and implementation of preferential trade agreements, can actually impose compliance costs that act as barriers to international trade, such as through RoO. In my third and last chapter, I highlight the importance of the transport sector for intranational trade and essentially show that policy-induced trade barriers in this sector can affect economic outcomes not only in the target sector, but also beyond – in a country’s upstream and downstream industries.