Auto glass experts debate cause of spate of shattered windows in vehicles on northern Colorado roadways (video)
Emma Pettit, The Greeley Tribune, July 1, '15
"... not everyone agrees with the task forces reasoning. A few auto industry experts were shocked when they initially heard about the shattered windows the more information they learned, the more it didnt make sense to them.
For Caleb Perriton, it was odd side windows, instead of windshields, were getting damaged. Hes the director of education at WyoTech in Laramie, Wyo., and has worked in the automotive industry for more than 25 years. He said windshields take the regular abuse of rocks and gravel kicked up by vehicles not the sides of cars.
Zac Kreider, collision instructor in the automotive department at Aims Community College in Greeley, agreed and said to do damage, debris needs to strike a window at a 90-degree angle. Thats difficult to do when traffic moves in the same direction, such as on I-25, where many of these shattered windows occurred, Kreider said.
Kreider and Perriton also were puzzled because they said side window and back window glass, called tempered glass, is extremely difficult to break... . To break that glass takes considerable force, something just a pebble couldnt do, Perriton said."
The story does go on to quote some glass repair shop owners who agreed with the Task Force that the shatterings could have been caused by road debris, but none offer an explanation as to why the great majority of them were side and back windows as opposed to windshields, or why they would be concentrated on I-25 and rare on northern Colorado's other highways.