Imagine for a moment that no rail line ever had existed between Eugene and the coast. Imagine trying to build one in the 21st century.

Imagine the cost of acquiring rights-of-way across public and private property. Imagine the court fights over condemnation wherever property owners refused to sell.

Imagine the modern-day cost of building bridges and blasting tunnels. Imagine the succession of local planning and zoning permits, each one likely to be contested by neighboring property owners.

Imagine the thicket of environmental permits and regulations, followed by additional court fights with indignant preservationists.

All of that is easy to imagine. What’s harder to envision is success. This monumental project would take decades, and the chances of ever driving the golden spike would be slim.

So why engage in this irrelevant game of make-believe? Just to put into perspective the rail line’s extraordinary value to the South Coast: This one-of-a-kind resource is literally irreplaceable. The community must not let it evaporate without a fight.

A new report by the federal Surface Transportation Board provides one more reason for that conclusion.

We already knew closure of the Central Oregon & Pacific Railroad forced shippers to substitute trucks. We knew the substitution was creating economic hardship on those important local employers. The STB report adds a new wrinkle, looking at fuel consumption and the resulting air pollution.

Not surprisingly, trucks burn more fuel and create more pollutants than trains. Freight movement that previously burned about 300,000 gallons of diesel per year now requires more than 800,000 gallons. That represents nearly a 10 percent increase in the diesel burned by all of Oregon’s commercial truckers — with an associated increase in pollutants and greenhouse gases.

Those numbers are significant. More significant are the economic losses caused by losing rail service. Existing South Coast businesses have been bled pale by the extra cost of shipping. Other businesses — prospective employers that might like to relocate to this area — will choose other towns if we have no rail. We’ll never even know who they were.

 The area’s hopes of long-term economic health will dim markedly if the trains are silenced forever.

At this point, those hopes rest entirely on the Oregon International Port of Coos Bay. No other applicants met the Aug. 8 deadline for proposing to buy the rail line. While public ownership of the line may not be the ideal outcome, having no rail service is almost certainly worse.

 The next steps will involve careful evaluation of the opportunity and risk. If the port’s research reveals the venture to be a bad investment, the community may have no choice but to watch the tracks be torn up and the bridges be torn down.

If that happens, our little region will lose a crucial link to the outside world — a link we’re unlikely ever to replace.