When a gap to be bridged is too wide to be economically crossed by a single span structure, it is necessary to provide intermediate piers and install a multi-span bridge.
The positioning of intermediate piers is often dictated by the local geology and topography of the site. Otherwise, the positioning and quantity of piers depends upon the most economic balance between the cost of the piers and the cost of the bridge construction appropriate to the varying span lengths.
It is a design feature of CB200 Bridging(CB200 Bailey Bridge) that in addition to simple spans, it may also be erected to form multi-span structures. This can be done in two ways; either with continuous bridge trusses supported or as a series of broken-spans linked at each intermediate pier by span junction equipment. It should be noted that both of these options provide a continuous road deck for the traffic.