The result is that combinatorial, multiattribute auctions achieve economies of scope and density for the benefit of both carriers and shippers. Combinatorial bidding removes the need for carriers to hedge prices to cover worst-case inefficiencies (bidding high in case they do not win the bid for the back-haul route) With this type of auction,carriers can set prices on the basis of the routes,giving discounts on the basis of economies of scope and density.Logistics.com handles auctions for transportation by giving carriers free access to software that lets them optimize their routes.shippers benefit by getting lower prices.