Yes it will, IF the data has been built into the map, let us say in your area there are 10 low bridges but only 6 were know to the map makers, these 6 will cause a warning alarm but the other 4 won't, the RV1090 does not detect low bridges it can only raise an alarm when it enters a location it has been told about by the map dataso just driving around with the map showing(even in RV mode) will not show low bridges?