Route examining system and method

A system comprising:

• a first application unit configured to inject a first electrical examination signal into a conductive route from onboard a vehicle system traveling along the route, wherein the first application unit is configured to inject the first electrical examination signal into the route by injecting the first electrical examination signal having a first frequency into a first conductive rail of the route, and further comprising a second application unit configured to inject a second electrical examination signal having a different, second frequency into a second conductive rail of the route;
• a first detection unit configured to detect a first electrical characteristic of the route based on the first electrical examination signal;
• one or more processors configured to apply a filter to the first electrical characteristic to isolate a subset of the first electrical characteristic occurring at a first frequency range of interest, wherein the first detection unit is configured to measure the first electrical characteristic of the route along the first conductive rail, and wherein the first detection unit is configured to measure a second electrical characteristic of the route along the first conductive rail based on the second electrical examination signal injected by the second application unit into the second conductive rail of the route, and further comprising:
• a second detection unit configured to measure a third electrical characteristic of the route along the second conductive rail based on the first electrical examination signal, wherein the second detection unit also is configured to measure a fourth electrical characteristic of the route along the second conductive rail based on the second electrical examination signal, wherein the one or more processors are configured to apply a filter to the second electrical characteristic to isolate a subset of the second electrical characteristic occurring at the second frequency of the second electrical examination signal, the one or more processors being configured to apply a filter to the third electrical characteristic to isolate a subset of the third electrical characteristic occurring at the first frequency of the first electrical examination signal, and the one or more processors being configured to apply a filter to the fourth electrical characteristic to isolate a subset of the fourth electrical characteristic occurring at the second frequency of the second electrical examination signal the one or more processors further configured to detect a break in conductivity of the route responsive to the subset of the first, second, third, and forth electrical characteristic decreasing by more than a designated drop threshold for a time period within a designated drop time period.