Folks,
As a priority this is a no-brainer.
The costs could easily be recouped from the property owners along the right-of-way either through donations or an assessment zone. I will gladly donate and I am sure that the commercial apartment owners and hotels along the right-of-way, who would love to increase the ambience of their properties, would also donate and/or support an assessment district.
The short term cost is peanuts compared to the long term benefit. And the entire effort could be contracted out with little impact on staff time.
We live with this noise every day and every night and you can make it go away within six months - forever!
Just do it!
Peter