Robin said:
One could decide the RR goes GL in the hex south of the bridge...
But note that B6.2 was written about 13 years before RR rules were made and it just marks the difference between pontoon and non-pontoon bridges.
If B6.2 is a problem, just add "(exception to B6.2 for level change question)."
There has to be an elevation change between Level 0 and level 0.5 somewhere. On the bridge, between the bridge and the EmRR, or between the road and the bridge. Where that elevation change occurs should be defined.
I forgot to ask the obvious question earlier: why isn't there a RR coming out the other end of the bridge?
Why not make the other end of the bridge exit onto an EmRR, making the railroads and bridge all Level 0.5, keeping it consistent and, more importantly, simple?