Investigating Lock Delay on the Upper Mississippi River: a Spatial Panel Analysis

A set of 28 lock and dam sites on the upper Mississippi River is essential to transporting US agricultural commodities to the world market. Currently, increasing delay of tows and vessels at this aging lock and dam system have generated great concerns about the navigational efficiency of this inland waterway. However, limited studies have focused on the statistical analysis of the relationship between lock delay and lock characteristics. In addition, previous research on the association between lock delay and lock traffic, or other characteristics, have neglected the spatial dependence among locks although the departures (arrival distributions) at a given lock could affect (be affected by) the arrivals (departures) at the adjacent locks. The objective of this study is to examine the impact of selected factors on delay at the lock and dam system using a spatial panel analysis incorporating spatial interdependence among locks. Results suggest that a 1% increase in lockage processing time result in a 2.3% increase in lock delay considering both direct and spillover effects on the upper Mississippi River. Numbers of lockage for commercial vessels at a given lock also contribute to its own delay and delay at other locks. Our findings confirm the importance of incorporating spatial spillover effect in the analysis of delay issue on inland waterway given the interdependence among locks.