There are a slew of reasons that lead to these delays. Security reasons, weather delays and aviation system delays are just some of the reasons that are given by airlines. What is probably not specifically mentioned on that list is the unnecessarily slow pace of boarding.
Anyone who travels by air will know how frustrating boarding can be. The VIPs get on first and only then the rest of the passengers are allowed to board. When you finally get on board, you have to weave in between the other passengers who block the aisles as they try to get their cabin luggage into the overhead compartments. Cumulatively, all of this results in delays and affects the on-time performance of an airline. Now, companies are trying to speed up things.
Engineering minds are also devising ways and means to make more space available within the existing space on aircraft, to help passengers move around with greater ease. Hank Scott, an engineering teacher has now created a “slide-in-aisle” seat that can be pushed aside temporarily at the time of boarding. He is currently attempting to get approval from the FAA for this design. If that happens, it could very well ease the boarding “traffic jam” on airplanes and also ease passenger woes.