Foster: Divert trucks on I-81 to rail. The Virginia Department of Transportation is studying the future of Interstate 81. Some have proposed tolls on trucks.

In your lead editorial of July 22 on Interstate 81, you state, “One obvious fix is to add more lanes.” Sorry, I beg to differ. That doesn’t help. More lanes beget more traffic. It’s been true everywhere, nowhere more dramatically than in California, where expressways now 8 – 10 lanes wide in each direction, are still gridlocked and become huge parking lots.

The problem with capacity on I-81 is, and always has been, freight. There are too many trucks. If it were just cars, we would be fine with what we have. So any time someone complains about needing more lanes, it’s because of the high density of truck traffic.

It follows, therefore, that if one could do something about the through-trucks, the gravity of the situation would be considerably improved. Massive new highway construction could be avoided, or at the very least deferred, possibly for decades.

Not much can be done about local trucking, but a high percentage of trucks in Virginia on I-81 are passing through the state; i.e., neither originating nor terminating their hauls here.

Serious consideration needs to be given to handling the through-trucks on trains, not just for the 325 miles of I-81 in Virginia, but for the almost 600 miles between Harrisburg, Pa., and Knoxville, Tenn., where a Norfolk Southern line parallels the highway the whole way. This concept has various names, Truck Ferry, Land Ferry, and Rolling Highway. It is widely used in Europe by operators Hupac, RAlpin, Ökombi, and others, but has never been tried in North America.

Entire trucks are driven on and driven off trains. Sleeping accommodations are provided for drivers. Attractive productivity benefits accrue to truckers by having their rigs continue to move while they sleep. As long as the rail service can be provided at highway competitive speed, reliability, and cost, why would a trucker want to drive?

This service partnership has benefits for railroads, truckers, and the public. Railroads get new business hauling through trucks, the truckers get to keep all their current business and make more trips per month, and the public gains from fewer trucks on the interstate. Not only is there more room for cars, but also significant health and safety benefits derive from less diesel particulate emissions and fewer crashes. A corollary benefit of railroad upgrades that can attract and handle large volumes of diverted trucks is to enable passenger rail service to be extended south of Roanoke and into Tennessee and north through the Shenandoah Valley.

Unfortunately highway competitive speed and reliability cannot be attained today on the parallel NS rail line because it is mostly single-tracked. Too much time would be lost taking sidings to wait for trains moving in the other direction. Thus, a significant rail upgrading would be needed to support a truck ferry operation. There would need to be at least two tracks throughout. But adding a second rail track takes only 20 feet of space, mostly on existing right-of-way, to achieve up to a seven-fold increase in throughput capacity.

In studies seeking solutions to the I-81 situation, separating the through trucks onto trains makes good sense and needs to be evaluated on a life-cycle cost and benefits basis versus new highway construction.

SB-971 that passed in January, known as the I-81 Corridor Improvement Study, provides a new opportunity to make this kind of life-cycle cost/benefit analysis. Can public investments in new rail capacity yield a better return than highway widening? Now is a good time to find out.

The text of the bill does not specifically require a multi-modal focus. But Transportation Secretary Valentine has assured me that it will be a multi-modal study. “The bill does not preclude it, so we will do it,” she told me at a public hearing in Roanoke on May 10.

Let’s hope so and let’s encourage this approach with our public comments. It is true that the new I-81 study is focused on tolling trucks. Having heavy trucks pay a share more commensurate with the pavement and bridge impacts they inflict is a reasonable quest. But separating the heavy trucks onto rail would be even better.