This paper was presented at the session titled `Unique bridges: unique renewals in the public eye'. This $55.3 million project on the Angus L. Macdonal Suspension Bridge across Halifax Harbour was completed in Fall, 1999, and covered approach spans deck replacement, expansion from two to three lanes, and improvements to the approaches and exits. The primary goals were: replacing deteriorating reinforced concrete deck in the approach spans and widening for a third (reversible) traffic lane, increasing the peak directional capacity by 100%. The project included: new orthotropic steel plate deck (OSPD) in the approach spans; widened concrete infilled grid deck in the suspended spans; addition of a reversible third lane; new cantilevered sidewalk and bikeway; thin lightweight wearing surfaces; improvements to approaches; electronic toll collection; variable message and lane control overhead signs; lane control gates; surveillance cameras; ice detection system; highlighting-accent lighting. The bridge could not be closed during peak traffic periods, resulting in major practical and scheduling challenges. The deck replacement work was carried out at night. Daytime work proceeded with two traffic lanes and the sidewalk open. The night work introduced additional issues, including noise, light pollution and safety. Traffic management during construction involved public relations, working in off peak hours, co-ordination with emergency services and public transit authority, careful channelisation, signage and operation of shuttles. The public relations program was implemented to provide project information and advise of bridge closures. The bridge was upgraded and widened with minimal disruption to traffic. Cross-harbour travel times during peak traffic periods have been reduced by 15 to 20 minutes. The Commission has computerised traffic control systems at their disposal to monitor traffic, display information messages and control the direction of travel for all three lanes. (A)
Samenvatting