Ask Mr. Answer Person: "Who controls the colored lights on the Trout Run Trail Bridge?"

Paul e-mails Mr. Answer Person: "I had a question about the Trout Run Trail overpass that goes over highway 9.  I drive under it multiple times a day and every night when driving home.  I often find myself wondering who controls the color of the LEDs under the bridge and how do they choose the color of it?  I'm just curious if it a totally random decision of what color it should be or is it planned out according to something?"

Mr. Answer Person says: Your question is just in time for St. Patrick's Day, when lights on the TRT bridge will turn green.  Here's a story we posted in 2012, with your answer at the bottom of the story:

"The best views of the Trout Run Trail Bridge over Highway 9 might be at night.  That's because three different types of LED lights have been added to the bridge.

Project engineer John Hjelle from Erdman Engineering in Decorah says four foot long and six foot long "color grazes" manufactured by Philips Color Kinetics have been put up on the underneath of the bridge structure.  They contain red, green and blue LED lights than can be computer-adjusted so that a wide range of colors can be created.

For instance, recently a test of the LED lights was done to display blue and red lights last Friday night, when the Decorah Vikings were playing a football game.  City officials have also tested an orange, red and yellow display for weekend fall color tourists and a constant blue color that highlights the features of the new bridge.

In addition to the color grazes on the bottom of the bridge structure, there are 24 white LED light displays on the top walkway of the bridge, installed to improve lighting and security.  There are also four "color blast" LED light displays on the side of the bridge.

All of the lighting is controlled by a computer at Decorah City Hall.  Hjelle says special displays can be created for Halloween (orange and other colors); Christmas (red and green), St. Patrick's Day (green) and Fourth of July (red, white and blue)."