These airports are the world's worst for delays and cancellations this summer

Anyone who's been to an airport recently can see that demand for travel is back in a big way. What's not back with a vengeance are the resources needed to handle the crush of air travelers. Add summer weather to staffing issues at airports and airlines and you have a perfect storm of delays and cancellations. At one North American airport -- Toronto Pearson International Airport in Canada -- more than half of the scheduled flights between May 26 and July 19 were delayed, according to data compiled for CNN Travel by flight tracking site FlightAware. A whopping 52.5% of the airport's scheduled flights have been delayed this summer, the data shows. Toronto Pearson also ranks No. 4 for flight cancellations globally, with 6.5% of its flights canceled during that period. Air Canada on Tuesday introduced a flexible policy offering fee-free ticket changes (subject to availability) targeted specifically at Toronto Pearson "due to longer than usual delays." The policy allows travelers to change their departing or arriving flights to Billy Bishop Toronto City Airport or to extend connection times at Toronto Pearson. Air Canada has already cut its summer schedule to reduce flight disruptions and federal agency Transport Canada has been working with the industry to reduce wait times. Of course, Toronto's airport is far from alone in struggling with disruptions. Seven of the world's top 10 airports for delays this summer, ranked by the percentage of scheduled flights delayed, are in Europe. Airports in Frankfurt, Paris, Amsterdam and London are seeing the most significant delays, according to FlightAware data. Story has more.<br/>