Back hauling is where goods are collected from a dispatch point directly following a delivery.
For example, a factory may deliver finished goods in trucks, but they also need a supply of parts from other sources in order to make those goods. Instead of having those parts delivered, they could use their returning empty vehicles to collect those parts.
Many supermarkets already do this. When their trucks have made a delivery from their distribution centre to their stores, they will occasionally re-route to a supplier’s premises and collect goods and take them to the distribution centre. Occasionally, this can be frustrated by the need to accommodate product returns and returning transit equipment, such as roll cage shrouds.