If you have a garage door that was installed in the last two decades, and if it has an automatic, motorized opening system, it probably has a light sensor and a pressure sensor. When something breaks the light beam, if the door is coming down, it stops and reverses direction. The same is true if it encounters unexpected pressure before it is all the way down.
These safety features are now mandatory and required by law. This has not always been the case, though, as the laws saying they must be used were instituted in 1992. This happened after a landmark court case in which the safety and design of these doors was called into question. The safety features had been options before, meaning people had to pay extra to get them, but the new laws said they had to be used on all doors.
This does not mean older doors won’t have them, of course. Even standard doors often had pressure sensors, but they didn’t have the light systems to detect something below the door before contacting it.
There have been problems with both systems in the past. The pressure system can wear down over time, for example, meaning the owner may think the door is safe when the reality is that the safety features aren’t working at all. When children or adults are trapped underneath, they could be injured or even killed by the heavy door and the motor that tries to push it flush with the ground.
Even with new garage doors, defective safety systems can still make these doors dangerous, especially for small children, so parents need to know their legal options when kids are injured in Illinois.
Source: Garage Door Repairs, “Why my garage door opener does not have sensors / safety beams?,” James Smith, accessed April 15, 2016