Another source of costs is linked to various official and informal payments levied along the transit route (Arvis et al., 2011). For example, “In many environments the complexity of the supply chain means that traders or their forwarders need to spend more time and staff to get things done, and this adds to the costs. It has been shown that in some cases, like Western Africa, these additional costs are on a par with the cost of trucking”. Transit chains are thus subject to inefficiencies and “even rent-seeking activities and corruption” (World Bank, 2013).