Rail Freight as a Means of Reducing Roadway Congestion

As congestion levels have grown on both urban and intercity highway routes, state and regional transportation planners are starting to look more broadly at alternatives that can hold down or reduce traffic growth. Planners have long considered modal diversion from road to rail for passenger travel, but less attention has been given to opportunities for modal shifting of freight as a means of addressing roadway traffic. Yet it is becoming increasingly clear that railroads can offer a potentially viable alternative to trucking in some situations. This alternative becomes of particular interest when expanded use of rail freight can reduce either existing traffic congestion levels or the need for expanding highway capacity in the future. This paper summarizes findings from NCHRP Project 8–42, which examined the feasibility and value of rail freight solutions as a means of reducing highway congestion, and these solutions’ implications for public planning. It defines the range of rail freight strategies that can be applied to mitigate the growth of traffic congestion and discusses the types of situations in which they can be most relevant. It describes the economic and institutional factors affecting the feasibility of diverting some truck freight to rail, and it lays out a structural framework for evaluating the relative benefits of these options.