Matches for load or transportation services with transportation service providers (TSPs) are established, and estimated arrival times are provided. A transportation service request is arranged and an estimate of time of arrival is made based on an estimation of a time for performing a delivery of the load or provide the transportation service, and the time of arrival estimate is adjusted by at least one external factor expected to affect transit time. An anticipated turn-around time for availability of the TSP is made for a subsequent leg or backhaul and the adjusted time of arrival estimate and the anticipated turn-around time are used to estimate a time of availability of the TSP for the subsequent leg or backhaul. An accepted bid for the subsequent leg or backhaul is made based on an estimated time of availability.