3.0 metres with the heaviest superstructure segment approaching 140 tonnes. Balanced cantilever construction is used for erecting the cable supported superstructure as compared to span-by-span construction for the approaches. For every second segment, cable anchorages are provided. A total of 264 cable stays are used at Bandra channel with cable lengths varying from approximately 85 metres to nearly 250 metres. The tower is cast in-situ reinforced concrete using the climbing form method of construction. The overall tower configuration is an inverted "Y" shape with the inclined legs oriented along the axis of the bridge. Tower cable anchorage recesses are achieved by use of formed pockets and transverse and longitudinal bar post-tensioning is provided in the tower head to resist local cable forces. A total of 160 cable stays are used at Worli channel with cable lengths varying from approximately 30 metres minimum to nearly 80 metres maximum. Like the Bandra channel, the tower here is also cast in-situ reinforced concrete using the climbing form method of construction but the overall tower configuration is "I" shape with the inclined legs. Similarly, tower cable anchorage recesses are achieved by use of formed pockets. The foundations for the main tower comprise 2-metre-drilled shafts of 25-metre length each. Cofferdam and tremie seal construction have been used to construct the six-metre deep foundation in the dry. Bridge management Toll collection The Bandra end of the toll plaza has 16 approach lanes. The toll plaza is equipped with an electronic toll collection system. At both ends, the toll collection options include: Automatic electronic payment system through On-board Units mounted on vehicles for frequent-commuters that enable vehicles to pass without stopping Semi-automatic cash-less electronic payment via a smart card in unattended lanes Manual toll collection for payment by cash, to a toll attendant Power supply & lighting The bridge has a reliable and redundant power supply, backed up by diesel generators and auto mains failure panels for critical loads, such as monitoring, surveillance, emergency equipment and communication services including aviation and obstruction indicators. BWSL exclusively uses energy saving illumination systems. Surveillance and Security An intelligent bridge management system (IBS) provides traffic information, surveillance, monitoring and control systems. It comprises CCTVs, automatic traffic counters and vehicle classification system, variable message signs, remote weather information system and emergency telephones. The control centre is located near the toll plaza along with the electronic tolling controls. The control system uses fibre-optic