A field based model was used to assess the mechanical transmission of PRRS . The model involved a replica of a common farm workers behavior during cold weather, below 0^o C. The model used common fomites (boots and containers), vehicle sanitation, transport and the movement of the workers to track the spreading of PRRS. A strain of PRRS was put into carriers that were made up of water and snow and then put on the undercarriage of a truck. The truck then drove 50km to a truck was where the drivers boot came into contact with the carriers. Then the truck was driven another 50km to a simulated farm where the drive walked around and mechanically spread the virus in the anteroom. From there, common containers made contact with the floor drippings. Then all the pieces that came into contact with the carriers were sampled to track the spreading of the virus. This was replicated ten times. At several sampling points PRRS virus nucleic acid was detected in 8 of 10 replicates. In each of the 8 samples that did test PRRS positive infectious PRRS was detected on the surfaces of containers. All the control (non-inoculated) tests found no sign of PRRS. Leading researcher to believe that  mechanical transmission of PRRS can occur during coordinated sequence of events is cold weather.