The following nomenclature is used to describe the components of the bridge model.

Item	Description
Segment	An individual precast segment
Closure Joint	A cast-in-place concrete joint connecting segments together to form a girder
Girder	A sequence of segments and closure joints. A girder can be many spans in length.
Group	A group is a collection of side-by-side girders.
Span	That portion of the bridge between permanant piers
Permanent Pier	The permanent substructure elements of the bridge including abutments and intermediate piers
Temporary Support	Temporary works to support segments during construction including erection towers and strongback hangers
Bridge	The bridge consists of all the groups

In the image below, there are two groups. Group 1 consists of Spans 1 and 2 and there are 6 girders in the group. Group 2 consists of Span 3 and there are 4 girders in the group.

The girders in Group 1 consist of two segments and a closure joint. The segments are supported on the permanent piers Abutment 1, Pier 2 and Pier 3 as well as an erection tower Temporary Support. The girders in Group 2 have one segment.