Road bridges generally cross bodies of water, or low lying areas along the road network.
In Figure 2.2.4.1a the shadows cast by the bridges are evident. The railway bridge is significantly thinner than the road bridges.
In Figure 2.2.4.1b the Road Bridge Line appears as the darker blue/grey line in the centre of the road and the lighter blue edges, compared to the Railway Bridge Line which is all one color.
Regional Considerations:
Figure: 2.2.4.1 Representation of Road Bridge Lines.