The Bologna San Donato railway test circuit (Italian: Circuito ferroviario di prova di Bologna San Donato) is a railway rolling stock testing facility located in Bologna, Emilia-Romagna, Italy.
For decades, it was the largest Italian railway freight yard in terms of size and traffic.
The launch saddles in Bologna San Donato were closed in 2012; from that moment on, the yard only hosted trains that were carrying out re-composition maneuvers, and it soon became a depot for rolling stock awaiting demolition.
[1] At the beginning of 2018, the decision was made to repurpose the external circulation circuit and build a new curve, so as to form a closed railway path, consisting of an oval about 6 km in length, to be used as a test railway circuit.
[1] The circuit currently allows test runs of new rolling stock; it also allows testing of rolling stock without a certificate of admission to service from the Italian National Agency for Railway Safety, as the circuit is outside the national railway infrastructure.