Traffic noise generated by existing traffic and anticipated future traffic is one of many important criteria to help determine appropriate design alternatives. Between October and March, Civiltech Phase I staff conducted noise monitoring for the North Lake Shore Drive Phase I Study.
Sightseeing Along the Drive
The boundary for the monitoring included a representative range of places along the project, within 500 feet of the mainline of Lake Shore Drive. The team monitored 44 different locations including spots within Lincoln Park and at the urban edge – where the City meets the park. The locations provided the team an interesting tour of the project corridor with a wide variety of spots including the rooftop garden at Lake Point Tower, Diversey and Belmont Harbors, the Lincoln Park Community Garden and Honeybee Grove, Ohio Street Beach, the Saddle and Cycle Club, and the rooftop patio of Hollywood Tower.
The team walked and biked between locations, using a bicycle child trailer to haul their equipment. In addition to the sound monitoring gear, they also needed traffic counting equipment as well as general supplies such as data sheets and clip boards.
Monitoring and Modeling
Highly sensitive noise meters were activated at 15-minute intervals recording the minimum, maximum, and average decibel levels. While monitoring the noise, the team also counted the traffic volumes that create the noise. The traffic count is then entered into the computerized traffic noise model and the result is compared to the sound collected to confirm the accuracy within +/- 3 decibels. Once it is determined that the model and noise data gathered are consistent, the team can add the proposed roadway design and projected traffic to the model to predict future noise levels after the project is in place. The goal of the modeling is to determine if traffic noise impacts will occur and if so, evaluate and recommend mitigation.
Challenges to the Exercise
Weather and wind conditions presented a challenge to the noise monitoring efforts. The team carried a weather vane that captures wind speed, temperature, and humidity, all of which factor into the noise measurements. The presence of too much wind sound can affect the accuracy of the data collected.
Another challenge was construction taking place on buildings within the study area. The team preplanned their noise monitoring locations with a goal of being spread out evenly around the project area. If they arrived at a location and discovered construction noise, they had to reevaluate the location and find an alternative.
Ambassadors for the Project
While the noise monitoring is a required component of the Phase I study, it has many enjoyable components. For the North Lake Shore Drive project, the noise monitoring efforts offered the team the opportunity to do field work in a variety of interesting locations. The work also provided a great opportunity for them to be ambassadors for the project. The team took time to talk to the general public, explain what they were doing, and help build enthusiasm for this exciting project.