A number of manufacturers offer precast footbridge deck units, usually prestressed beams with pre-tensioned strands. The deck beams usually take the form of box, Tee or double-Tee sections. Fixings for handrails are cast in or the units can be supplied with precast concrete parapets where additional protection is required, e.g. over railway lines.
The beams are best suited to rectangular, straight layouts. The dimensions and weight of units of units are limited by transport and the available size of crane for erection. Typical spans range from 10 to 40 metres.