Police said the boys, ages 11 and 14, were arrested in connection with the incidents, which occurred during the evening hours of Aug. 19 and Aug. 21.
Authorities said the juveniles threw various objects from the overpass, striking moving cars and trucks below. In total, 17 vehicles were damaged. Two people suffered non-life-threatening injuries, and no one was seriously injured.
Residents who live nearby expressed concern about the alleged actions.
"Scary, anytime someone throws something over the overpass," said Melissa Williams of Coatesville.
Others questioned why the incidents occurred.
Some residents also raised concerns about supervision.
"I don't understand the reason for it. There's no reason. You got parks you got this that you can go to. You can go down to the creek and throw stones in the creek if you want to. Not at cars," said John Miller of Coatesville.
The 11-year-old and 14-year-old are facing multiple charges. Police are asking anyone who was traveling on Route 30 on Aug. 19 or Aug. 21 and whose vehicle sustained damage from debris to contact them.