Chris Preto (left) with Joe Smithson of the Ohio Department of Transportation (ODOT) District 8.
The Ohio Department of Transportation’s Lytle Tunnel Rehabilitation and Modernization Project, designed by Mott MacDonald, has received the 2018 ODOT/ACEC Partnering Award for Excellence in Highway Design in the category of projects with a construction value over $20 million. During the award ceremony, a video about the project was shown to more than 400 ODOT employees and consultants.
Lytle Tunnel, the only mechanically ventilated vehicle tunnel in Ohio, conveys Interstate 71 under several city streets and historic Lytle Park in downtown Cincinnati. Opened to traffic in 1970, this six-lane, three-cell tunnel accommodates both northbound and southbound mainline traffic and a southbound exit ramp to Third Street.
Mott MacDonald rehabilitated and modernized lighting, electrical, mechanical, ventilation, and emergency systems, as well as designing standpipes, tiles, pump stations, barriers, pavement, joint and structural repairs, traffic control, intelligent transportation systems (ITS), and supervisory control and data acquisition (SCADA).
To bring the tunnel up to current codes, a massive 25-foot-deep excavation in Lytle Park was needed to accommodate three new axial fans. This alternative had the least long-term impact to the Park and was the most economical solution.
An integrated, interdisciplinary process was designed to provide a reliable fire and life safety system. Linear heat detection will locate the fire, and all tunnel ventilation fans will be activated so that tunnel dampers will direct the full air capacity to supply or exhaust from the incident cell. Meanwhile, fire alarm activations and signals are sent to emergency responders, and “Tunnel Closed” signs flash. Emergency responders can pressurize the tunnel standpipe with water and take control of the SCADA-initiated tunnel ventilation system.
The Lytle Tunnel is one of the first tunnel installations in the US to use LED lighting. The lighting design included luminance cameras that adjust illuminance in the tunnel to match light levels outside the tunnels.