@L3GO-Ed, you really should not have to split your Alignment to create the bridge. You can just simply add a bridge on the existing Alignment as a bridge zone using a right-mouse-button (RMB). You probably have a Planning road on which you want to create a bridge? Below some more information on the different types of roads.
At the moment there are 3 type of Roads in InfraWorks 360:
Planning Roads: very simple horizontal and vertical geometry and these roads are given you by the Model Builder. These can be converted (RMB) to more intelligent roads below.
Design Roads: more intelligent roads that have intelligent parts like tangents, curves and spirals. These have separate horizontal and vertical design functionalities and can have bridges along the Alignment. Design roads can show the vertical profile in a clear diagram.
Component Roads: these are the most intelligent roads at the moment. These have seprate editable Assemblies on all sides of your Alignment as Components and can be replaced and added. The whole custom roadsection can be added to a library. These roads alse have the new roadsection views with cut and fill data. Also, these roads can have bridges along the baseline.
Let me know if this helps you?