A method and computer program product are provided for monitoring integrity of a railroad train and determining passage of the train relative to a plurality of virtual blocks defined by wireless transmissions along a section of track over which the train travels. The virtual blocks provide safeguards for the travel of the train relative to other trains on the section of the track when there is a shared use of the section of track. In aspects thereof, the method allows collecting data useful for evaluating conditions that may affect train integrity from at least one sensing device at a end of train location. The method further allows collecting data at a head-of-train location, with the data collected at the head-of-train corresponding to the type of data collected at the end-of-train location. The data collected at the end-of-train and at the head-of train location is processed to determine whether the entire train has cleared a respective one of the virtual blocks. In the event this determination is unable to reach a clearance for the respective block, a cautionary status is associated with the virtual block. The cautionary status for the virtual block is automatically communicated to an offboard system, which is responsible for managing shared use of the track by other trains.