Lockage delays on the waterways occur due to increased tonnage and the ever-increasing need for double lockages. Delays can also be attributed to lock component failures or tow-related accidents at the locks and dams.

Built in the 1930s, the system was originally designed to handle tow sizes (tow boat, plus barges) of up to 600-feet long (except at Locks 19, 26, and 27 on the Mississippi River). Present-day tows routinely push fifteen barges with a length up to 1,200 feet long. These large tows require double lockages – a costly and time-consuming process.

The 1988 Inland Waterway Review identified five locks on the Mississippi River (locks 20, 21, 22, 24 and 25) and three of the eight locks on the Illinois Waterway (La Grange, Peoria, and Marseilles locks) as being among the 17 locks in the country with the highest average delays, total delays, highest total barge transit processing and lockage times, and highest rate of lock use.

The Upper Mississippi River - Illinois Waterway System Navigation Feasibility Study found that in 1992, tows at Locks 20-25 were delayed a total of 87,000 hours at a cost of $35 million while waiting to be locked through. Lock 22 was the most congested lock in the study area. The average delay for the 3,306 tows that used the lock in 1992 was seven hours. Assuming a cost of $400 per hour (industry figures for that era), this delay cost $2,800 per tow processed at Lock 22. In addition, 80 percent of these tows had to double lock; a process that added an additional hour to each lockage. During the period 1988-1992, river traffic grew an average of 4 percent per year. All other locks on the waterways also experience increased delays due to traffic growth.