Family travel patterns often lead us in the direction of Washington, meaning we've become all too well-acquainted over the years with I-85 up toward Petersburg. And then, as we occasionally glimpse the ghost of an old trackbed, my wife has to listen to more of my lame wisecracks about the Southeast High Speed Rail Corridor.

It takes a fairly humongous leap of imagination to see what transportation officials in North Carolina and Virginia see: Passenger trains roaring along at 80, 90, 100 miles per hour where now the fastest thing moving is likely to be a snake looking for a sunny spot to take a snooze.

One needn't be as old as Methuselah to remember when Amtrak did indeed make use of this route.

Travelers from Raleigh would climb aboard at the station near Peace College that's since been put to agreeable re-use by the Logan Trading Company garden center. The train would head north through Wake Forest, Henderson and the boonies of Mecklenburg, Brunswick and Dinwiddie counties in Virginia. At Petersburg, the route joined with the tracks that came up from Rocky Mount.

But in the early 1980s, the railroad company CSX decided that maintaining the right of way it owned was more bother than it was worth. The rails were ripped up north of Norlina, forcing Amtrak to reroute its trains from Raleigh on a dogleg over through Selma.

That's why Amtrak's northbound Carolinian and Silver Star today reach Petersburg via Selma, Wilson and Rocky Mount instead of taking the more direct path of yore. And it's why motorists on I-85 now and then cross an overpass that has nothing beneath it except brush growing where trains used to run -- and where it's hoped they'll run again, as soon as 2015. Run fast.

What will it take? To build the Southeast High Speed Rail Corridor from Washington through Raleigh to Charlotte would require an investment pegged at $3.5 billion.

No small potatoes there -- but at $7.5 million per mile, cheaper than typical interstate highways. And the whole idea would be to help take pressure off our increasingly congested roads for trips of a couple hundred miles or so. Raleigh to D.C. certainly would fit the profile.

The concept of a high-speed rail corridor for our region was hatched in the early '90s under federal auspices. Planning began in earnest in 1999, and a route was selected. Virginia and North Carolina now are cooperating on detailed environmental studies. Separately, the Federal Railroad Administration has looked at what would have to be done to cut travel time between Richmond and Charlotte to four hours and 25 minutes.

Last week's high-speed rail summit in Raleigh was a be-there-or-be-square event for all kinds of folks with a stake or interest in moving the project forward. Prominent on the agenda was an issue that's emerged as a stumbling block to efficient rail service -- how to blend freight and passenger operations while improving both.

As most Amtrak passengers in these parts can attest, delays because of competition with freight trains for track space are frustratingly routine. Too many freights, not enough tracks. It's an impediment to better low-speed passenger service, let alone high-speed. The summit promoted the idea of freights also taking advantage of the high-speed corridor. And, oh yes, freight companies such as CSX would be asked to help pay for the upgrades.

Cost, in fact, is the real impediment, at a time when transportation funding and every other kind of government funding that doesn't involve our troops in combat is stretched super-thin. But beefing up the country's rail network looks like the sort of investment that would pay big dividends.

A new study by the Association of American Railroads lays out a formidable number -- $148 billion, to be raised from both private and public sources -- as the cost of infrastructure improvements needed by 2035. It's either build more and better tracks, bridges, signals and so forth, or see the nation's already crowded primary rail lines become so overloaded that service would deteriorate severely.

That would be a blow to the economy, with shipment of everything from coal to new cars thrown for a loop. And it would generate even more pressure on highways. Don't we have enough trucks on the road already?

Rail was once the most practical means of long-distance overland travel, and it's always been key to shipping cargo. The interstate highway system made it more feasible to rely on cars and trucks. Now that the interstates are reaching their capacity limits, rail's time could come again.

We'll know we've done something right to keep us mobile when trains are outpacing the traffic on I-85 -- within eight years from now, if we're both smart and lucky.