eight switchable message signs, 54 traffic signals, two mast arms, 51 overhead lights, 12 emergency telephones, of power cable and of communication cable. Cracking and deterioration A routine inspection of Houghton Highway in 1991 found an alkali-silica reaction in the pre-stressed concrete piles. This reaction caused internal cracking of the concrete, and crumbling and spalling of the concrete leaving the reinforcing steel exposed to the marine environment. Approximately 500 piles were encased in concrete below the water surface and up to above the high water level. Above this point, an externally bonded carbon fibre reinforced polymer was applied, wrapping the column to cover the damage and contain and conceal the existing cracks. It was also believed that such composites offered re-strengthening and a protection of the piles through encapsulated resin during the lamination. The treatment work was completed in 2000, and the repairs and condition of the piles are continually monitored. Upgrading and political controversy Increasing traffic resulted in the bridge reaching its upgraded capacity in the late 1990s. In particular, vehicle breakdowns or accidents that resulted in the temporary closure of one or more lanes causing congestion and delays demonstrated the vulnerability of the situation. Tidal flow upgrade The Department of Main Roads undertook a further upgrade of the bridge's tidal flow system. Commissioned in 2002 at a cost of $1.8 million, this upgrade included the replacement of the overhead arrow and cross signals with brighter, LED displays, monitoring of traffic flows and conditions with supervision of the system data and view of the bridge by CCTV at the remote Traffic Management Centre in Woolloongabba, Brisbane. Operators were for the first time also able to close and open lanes as required from the remote location. The upgrade project suffered delays from "technical issues", resulting in the then Transport and Main Roads Minister, The Hon Steve Bredhauer, thanking Redcliffe residents for their patience. Six months later, the Minister apologised for extensive delays after the system failed when a council contractor cut both the main and back-up power supplies to the tidal flow system just before 10:00am. Evening peak hour traffic was severely disrupted and banked-up for several kilometres as the bridge fell into "safe mode" with one lane open in each direction for over 10 hours until Energex reconnected power at 8:00pm. Changes implemented after this incident included an improved back-up power supply that was separate from the main supply,