by communities fearing the loss of their transportation links. Unfortunately, this required an extensive modification to the Trans-Canada Highway route on the eastern slope of Kelly's Mountain ( high), resulting in a 180° "switchback". A safer alternative to continue the highway further east on a gradual descent of Kelly's Mountain toward New Campbellton, crossing at the northern end of the Great Bras d'Or channel was rejected. Likewise, a route between Beinn Bhreagh and Kempt Head at the extreme southwestern end of the channel (much wider waterway but avoiding Kelly's Mountain altogether) was never considered. A number of serious accidents have occurred on Kelly's Mountain and at the switchback at the base of the grade over the years, as many as six or seven accidents taking place in some years. Deck replacement By 2001, it was found the existing cast-in-place concrete bridge deck was in poor condition. Forty years of wear and tear from traffic as well as exposure to wind and salt spray necessitated a major overhaul of the Seal Island Bridge. The road deck needed complete replacement, and the steel truss work needed reinforcement. Engineers thoroughly inspected the rest of the bridge structure and found it to be sound and safe. A major deck replacement project was undertaken. Over the next three years, the original cast-in-place concrete bridge deck was removed and replaced using full-depth, precast, prestressed, half-deck width concrete panels. It was necessary to complete one lane at a time, starting with the south lane, leaving the other deck in place so the bridge could continue to be used for vehicular traffic. Construction was completed with minimal traffic disruptions, and the bridge remained open to single lane traffic throughout construction, with the exception of three, six-hour overnight closures planned per week. This project added several decades to the useful life of the bridge. The new high performance precast concrete deck system is much more durable than conventional systems since it is less permeable and crack-free under service load conditions. The deck system adopted is significantly lighter than a conventional cast-in-place concrete deck system. This has resulted in considerable savings in the amount of truss reinforcement required, while providing sufficient mass and stiffness for damping purposes. At the same time the guard rails (traffic barriers) were replaced over the entire length of the bridge, with the new guard rails set inside the main bridge trusses to better protect them