At 10.30am today, the driver of a low bed truck carrying a forklift, was on his way from Pomona to Nigel taking the route through Springs.
He said he heard a loud noise and underestimated the height of his cargo and the bridge.
The chains holding the forklift in place snapped when it fell onto the middleman just missing the pillars of the subway.
It landed on its side and the oil was flowing from it onto the tar road.
Metro workers tried to cover the oil with sand while two EMPD officers redirected the traffic on both entrances to and from the subway.
According to the driver the subway is estimated to be 3.1m high and the forklift on top of the truck is approximately 4.15m in height.
A truck was seen on the scene lifting the forklift onto its wheels.
The EMPD officer says they drove the forklift to the truck on the other side of the subway to load it onto the truck again.
The road was accessible to traffic again at noon.