According to the studies conducted by the ACP in 2005, the canal would reach its maximum sustainable capacity between 2009 and 2012. When it reaches this capacity it will not be able to continue to handle growth in demand, resulting in a reduction in the competitiveness of the Panama maritime route.
As approved by the Panamanian people, construction for the expansion project is slated to conclude by 2015. The ACP will use all possible means to stretch capacity until the construction is completed.
The proposed expansion of the canal by the construction of a third set of locks will allow it to capture the entire demand projected through 2025 and beyond. Together, the existing and new locks will approximately double the capacity of the present canal.
Critics such as former legislator Keith Holder, co-author of the legislation that created the ACP, point out that canal usage is seasonal and that even during the few months when it is most crowded, the bottleneck that slows traffic is not the locks but the narrow Culebra Cut, which has a limited capacity for large ships to pass one another.
Although the canal is nearing its maximum capacity, this does not mean that ships will be unable to transit it. Rather, the canal's growth capacity will stagnate and that it will not capture additional cargo volumes.
The former head of the Panama Canal's dredging division, Thomas Drohan, a critic of the expansion plan, discounts allegations that this is a problem in the short term. He argues that if the supply of any good or service becomes short, businesses can raise their prices; this would apply to Panama Canal tolls as much as it does to petroleum.