Replacing and rehabilitating structures increases safety of Caledon Trailway

Caledon is a town of approximately 80,000 people located northwest of Toronto in the Regional Municipality of Peel. The town has experienced significant growth in the past 10 years, and their 2024 Official Plan forecasts the town's population to increase to 300,000 by 2051.

The town's population growth and associated traffic has impacted its existing bridge infrastructure. The town conducts regular assessments of its bridges to assess their condition and safety. In 2021, the town retained Associated Engineering to assess four pedestrian bridges and two culverts to determine their condition and the need for rehabilitation or replacement. Project Manager, Sarvejit Nagi in our Toronto office, tells us, "After the condition assessment, we identified that Duffy’s Lane Bridge and Mill Lane Bridge on the Caledon Trailway needed maintenance."

The Caledon Trailway follows a Canadian National Rail line built in 1877 and later abandoned. The 35 kilometre Trailway runs from the hamlet of Terra Cotta to the community of Palgrave in Caledon. Today, the multi-use trail is heavily used by the public for cycling, walking, and horseback riding.

Duffy’s Lane Bridge and Mill Lane Bridge have a length of 12.9 metres and 7.9 metres respectively, and both are 2.17 metres wide with short railings. The Town sought to rehabilitate the structures according to the Ontario Structure Inspection Manual (OSIM) reports and make the bridges structurally safe. In addition, the Town wished to replace two culverts.

"We completed preliminary design and prepared life-cycle costs, which showed that rehabilitating the bridges was more cost effective than replacing them. We subsequently prepared the detailed design for the rehabilitation, as well as applications for permit approvals, and tender documents for four of the structures."

Without available record drawings, the team conducted surveys to capture dimensions and confirmed the design with field measurements and survey information.

Bridge Engineer, Jim Thomas, says, "We designed higher bridge railings, 1.37 metres tall, to improve safety for cyclists and pedestrians. As well, the bridges were widened to three metres to accommodate maintenance vehicles."

Bridge Engineer, Shuhao Chen, tells us, "To improve the durability of the bridges, we specified that the timber for main structural members be Spruce-Pine-Fir (SPF), Hemlock Fir, Grade No. 2 or better." In addition, the team specified that connections use galvanized steel lag bolts with predrilling holes to prevent timber cracking and the deck boards were fastened with GSK RSS Screws, rather than nails."

The Town awarded the construction contract for Duffy’s Lane and Mill Lane bridges in May 2024 and retained Associated Engineering to conduct contract administration and site inspection. We also reviewed the traffic plan and coordinated the construction with adjacent road construction contractors. The team also worked with the Town to provide notices and detour maps to trail users.

Caledon’s Chief Administrative Officer, Nathan Hyde said, “In improving accessibility from the trailway to local businesses, we are supporting our strategic priority of community vitality and livability, enriching the vibrancy and liveliness of our hamlets and villages.”

Key Associated Engineering staff included Sarvejit Nagi, Shuhao Chen, Jim Thomas, Catherine Du, Hannah Murphy, Don McBrayne, and Navjot Dureja.