Quieter Windows For a Busy Street in Denver, or Anywhere Else

[Burt L.]

 I need to get new windows for a property on a busier street that you can each car "whoosh" by on the front side of the house and will make it difficult for showings and this is a huge window at 8 ft wide by 5 ft tall. 

In looking through the forums, I saw a couple of recommendations for Milgard, that Lowes carries. There is also a general review at Lowes from a consumer that said they can no longer hear the bus go by after buying a MIlgard, but didn't specify which line of their windows. I'm also told having a triple pane is quieter than a double pane. Nobody in town carries this particular size that I"ve been able to locate and all want to custom order with large lead times and high prices. 

If I order the MIlgard Style Line in a double-pane from Lowes online, this largest window of the group is $503 and is an available size  and takes approx 3 weeks. When I call and have an associate from Lowes put the exact same window in an order through their software, the price increases to over $900. If I step up to the Milgard Tuscany which is a triple pane, the price rises to $1100 for just that window. 

I haven't found anyone in the Denver area that stocks this size but they all seem want to want to custom order it at large markups over what I can order myself from Lowes. I may not be giving the current window a "fair shake" as I'm sure its a low end Pella or JW from Home Depot and does have a break in it, but having a loud living room makes the property undesirable. 

I wonder what people can suggest to quiet down noise on a busy street through the window? Not sure I want to step up to an $1100 window on just the largest on the order, If I don't have to. 

Separately, I had a local, large rental property owner tell me that he sometimes splits large windows into two windows, in this case that would be 48' wide by 60: tall, adjusted for the 1/2" on each end. Probably hard to find 48 wide by 60" tall. 

This matter is the large, detracting item on the property and will impact any strategy utilized for the property so its important to solve.

Thank you.