For the Category 2 receptors (Radisson Hotel and Youth Hostel), noise exposure in terms of Ldn at 50 ft (each of the three noise receptors are approximately 50 feet to the centerline of the LRRT’s trackbed) were calculated as follows:
Leq (day) = SELref + 10 log (Ncars = 47 dBA
) + 20log(S/50 feet) + 10 log (Vd) – 35.6
Where SELref, the reference sound exposure level for Rail Transit at 50 ft from track = 82 dBA (FTA, 2006).
The following adjustments were made in accordance with the FTA manual:
Additional 5dBA for jointed track and additional 3 dBA for embedded track on grade.
Therefore, total Leq (day) = 47 dBA + 8 dBA = 55 dBA
Leq (night) = SELref + 10 log (Ncars
) + 20log(S/50 feet) + 10 log (Vn) – 35.6
= 46.6 dBA After adjusting for the jointed track and embedded track configuration, Total Leq (night) = 54.6 dBA
Ldn at 50 ft = 10 log [(15) x 10(Leq (day)/10) = 61.1 dBA
(9) x 10((Leq (night) + 10)/10)
] – 13.8
For the Category 3 receptor (St. Paul’s Episcopal Cathedral Church), noise exposure in terms of hourly Leq (h) at 50 ft was calculated as follows:
Leq (hour) = SELref + 10 log (Ncars
) + 20log(S/50 feet) + 10 log (V) – 35.6
= 46.8 dBA After adjusting for the jointed track and embedded track configuration, Total Leq (hour) = 54.8 dBA
Proposed Project Noise Exposure Levels: The proposed reintroduction of automobiles (cars and delivery trucks) to Main Street corridor would be an additional exposure to noise within the project’s vicinity. The FTA manual categorizes these automobiles as Highway/Transit Sources. The automobile vehicles would be restricted to an average speed, S of 15 miles per hour.
The future (2025) Average Daily Traffic (ADT) volume for the Preferred Alternative is approximately 5,000 ADT (see section 7.0 – Transportation). This would result in an hourly traffic volume, V of 209 vehicles per hour, with projected average hourly daytime,