I know that spot well. Used to ride over that nearly every week. Fell flat on my face a couple of times.
There's the fun choice near there of climbing alongside the viaduct or wussing out and going up the switchback path.
If you're heading back round the now defunct Earth Centre and follow the trail back to the Pastures you can enjoy the slippery as hell wooden bridge, and the track that carries on with wooden rails hidden in the grass.
To make life more fun most of the track is limestone (or dolomite) which packs hard, rots when wet, and becomes more slippery than ice.
I miss those runs along the canal side and up to Cusworth Hall to watch the sunrise over Doncaster. It was wonderful on freezing winter mornings