It is a commonly held notion that container lines are inefficient in the management of their container fleets. As boxes change hands from terminal to trucker to warehouse to shipper to carrier as they migrate around the world, keeping track of them is a perpetual challenge. Some have suggested that real-time track and trace through electronic transmitters might be a solution, but container lines have never embraced this idea. Yet, the numbers seem to indicate that container lines are getting more efficient in their use of containers.
 
According to Containerisation International figures, in 1995 there were 3.5 TEUs of containers for every 1 TEU of oceangoing slot capacity, but by 2008 there were only 2.3. In actual numbers in 2008, there were 27 million TEUs of containers in circulation as against 12 million TEUs of slot capacity. What explains the decline, which is fairly steady over the 13 years of data? Is it fewer inland and more port-to-port moves? Is it growth in vessel capacity outstripping container supply? I asked Bill Hamlin, the former president of the Americas region for APL and currently vice President, corporate newbuild projects for Norwegian Cruise Line and a partner in the Washington consulting firm of Jamian McElroy & Hamlin, LLC. He is also chair of the advisory council for Trojan Defense, a developer of nuclear threat sensors for containers and other applications.

Here are his comments:

Larger but less utilized capacity of the cellular fleet.
The trans-Pacific dropped dramatically so this impacts both
cellular utilization and container fleet requirements. The
latest economic downturns have had more impact and I had
heard from Chris Koch at the World Shipping Council that
up to 12% or more of the world cellular fleet was laid up.
In this case it skews utilization figures. I also believe
that carriers have probably off-hired a number of
containers or removed old containers from their active
fleets. It is hard to look at these figures only and
determine how much improvement has really been made in
utilization. I would like to see a comparison of actually
employed containers as a ratio of active cellular fleet
adjusted for utilization. Look at any major port city and
you see mounds of containers stacked up. The larger
question in my mind is the overall economics of the
carrier cost of equipment including ownership/lease and
repositioning costs. The carriers have pushed some of the
expense of the inland (move) to the importer and exporter but the
cost still remains and someone is paying for efficiency or
inefficiency. Optimizing loaded and empty movement is
based on good information and effective tools and the
ability to freely interchange equipment. So to answer your
questions, there has been improvement but is it this data a
good indicator?