A method for monitoring integrity of a railroad train (10) and determining passage of the train relative to a plurality of virtual blocks defined by wireless transmissions along a section of track (54) over which the train travels, with said virtual blocks providing 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, said method comprising:

identifying a plurality of failure modes that may lead to an erroneous determination that the entire train has cleared a boundary for a respective one of said virtual blocks; collecting data at an end-of-train location, said data being collected from multiple sensing devices (14), wherein each of said sensing devices monitors a different parameter and generates data useful for evaluating whether at least one of said failure modes has occurred;

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;

storing (40) a plurality of rules for relating the data collected at the head-of-train location to the data collected at the end-of-train location for reducing a probability of making an erroneous determination as to whether the entire train has cleared a boundary for a respective one of said virtual blocks;

processing (42) the data collected at said end-of-train and at said head-of train location using the stored rules to determine whether the entire train has cleared a respective one of said virtual blocks;

in the event said determination indicates clearance of said respective block, declaring said virtual block as being unoccupied and thus available for another train to enter the block; and

in the event said determination indicates a lack of clearance of said respective block, declaring said virtual block as being occupied and thus unavailable for another train to enter the block.