SD30 - The Potential for Shifting Virginia's Highway Traffic to Railroads

Executive Summary:
The 2000 Session of the General Assembly, through Senate Joint Resolution No. 55 stated the following:

"Requesting the Secretary of Transportation to expand the scope of her study on the desirability and feasibility of establishing additional intermodal transfer facilities (House Joint Resolution No. 704 (1999)) to include the potential for shifting Virginia's highway traffic to railroads."

Interstate 81 was cited as an "acute example" as its current traffic is made up of as much as 40 percent trucks although it was designed to carry no more than 15 percent.

Study Purpose and Conduct

This report presents the results of a study designed and commissioned by the Virginia Department of Rail and Public Transportation to address SJR-55. The purpose of the study is to determine if the potential exists to divert enough highway traffic from I-81 to rail transport to significantly impact the need for planned improvements, and if the impacts over time would justify public expenditures for rail improvements. The approach to making the determinations involved a number of factors.

A variety of data on truck movements, I-81 characteristics and improvement plans, and railroad plans were gathered and analyzed. The analyses conducted examined the reasonableness of both highway and railroad plans and cost estimates, the amount of highway traffic which might be diverted to rail, and the extent to which those diversions might impact I-81. In the case of the latter, both planned capital expenditures and long-range maintenance and environmental consequences were considered.

Data Collected

Data on truck traffic (base and forecast years) were obtained from commercial freight data sources and prior VDOT studies and work in which it had participated. I-81 traffic and roadway data, including forecasts were provided by VDOT. Potential rail passenger volumes in the corridor were supplied by DRPT.

Details of the Norfolk Southern (NS) proposal, including estimates of potential diversion and rail line improvement costs, were supplied by the railway. Officials of the company involved in preparation of the estimates were made available for questions and discussion in two meetings.

Analyses Performed

A number of analyses were performed in conduct of the study. First the various truck traffic flows contained in the various databases were examined and assigned to the highway system. The trucks that would use I-81, all or part of the length in Virginia, were identified by route segment.

The NS freight diversion methodology and estimate were reviewed and compared with other estimates and current market shares. Diversions of 10 and 25 percent were examined. The potential to divert automobile occupants to passenger trains was found not to be significant. In the final analysis, actual diversions are dependent on the quality of service the carrier is able to provide. A diversion potential of around 10 percent (*1) is a reasonable expectation.

The cost estimates prepared by both VDOT for the 20-year I-81 program, and by NS for its rail route parallel to I-81 were examined and found to be reasonable. Both are, however, order-of-magnitude estimates based on conceptual/preliminary planning, and would need to be refined at some point.

Highway impacts were estimated using the Highway Economic Requirements System (HERS). HERS is a comprehensive highway performance model used to develop testimony for the U.S. Congress. Output from HERS is used in preparing the U.S. Department of Transportation's biennial report to Congress on the "Status of the Nation's Surface Transportation System."

HERS uses the Highway Performance Monitoring System (HPMS) database, which is a stratified random sample of a state's highway system. Each state transportation department collects traffic, pavement, ride quality, and other highway data needed to update the database each year. FHWA uses data from all states to develop reports for Congress. In this case HERS was applied to Virginia's database to produce state-specific reports.

Using the HERS model, it was determined that the planned improvements to I-81 will have to proceed, and, in fact additional capacity improvements should be considered. Even with additional capacity improvements, the removal of trucks (diverted to rail) impacts the amount and timing of those improvements. An analysis of the present value of the benefits that would be attributable to the diversion of trucks over the 22-year study period was conducted. The results reveal that at a 10 percent diversion level, almost $400 million worth of benefits are generated which increases to almost $1 billion at the 25 percent level. The 25 percent level is the upper most end of the range and would only occur under almost ideal conditions.


The analyses conducted indicate that consideration of public investment in rail improvements in the I-81 Corridor is .warranted based on the potential to accrue public benefits. There are still many unanswered questions and issues to resolve, but that should not deter further consideration and examination of the NS and other similar proposals. Highway improvements in addition to those planned are needed. It is believed that the rail capacity improvements proposed exceed those necessary for the projected intermodal volumes. The Commonwealth should work with NS to reduce the scope of rail improvements to that which is required.
(*1) Percent of trucks with dry van semi-trailers moving in excess of 500 miles. Trucks with those characteristics comprise approximately 70 percent of all trucks.