Mike has hit the nail squarely on the head with regard to freight of substantially high value. The competition there is between air freght and trucking; rail transport seldom enters the picture, with the singular exception of moving containers from the piers to "distribution centers", and there only if the distribution facility is a fair distance inland.
One subject which would interest me very much, and which, for whatever reason, seems to have very ittle research available, is the rail carriers' loss of time-sensitive freight of moderate- to high-value as the highway network developed. When the first long-distance truckers emrged, around 1930, the railroads answered, for a time, with dedicated freght service in intermediate corridors like New York-Buffalo, New York-Pittsburgh and San Franciso-Los Angeles. Sometimes, these runs, which usually operated overnight, were accorded first-class status in Employees Timetables of the day,
After World War II, several of the Eastern trunk lines made a final play with sevices dedicated exclusively to less-than-carload (LCL) traffic - NYC's Pacemaker and B&O's Timesaver/Sentinel services sported a fleet of specially-painted, easily-identifaible boxcars. And the Pennsylvania had several westbound freights, none of which operated on Sunday night/Monday morning, all symbolled "LCL". But nothing worked well as completion of the interstate highway system enhanced the truckers' advantage. The PRR "LCL" fleet was eventually redesignated as the "PR" series, and filled itself out by returning empty cars that formerly moved west on extras.
For whatever it's worth, during the years this writer worked in common carrier trucking as a dispatcher, the highway carriers never seemed to prosper from small shipents either. Prior to deregulation, if the major carriers didn't have direct authority to serve samll communities, they had to turn the shipment over to a small local carrier who did (and just about everybody had some gaps in their authority) and often didn't follow through on the originating carrier's commitment as quickly. When deregulation came to pass, a handful of large carriers expanded into the monopolized local markets, and hundreds of small carriers bit the dust. It wasn't long before all but the strongest of the major players followed suit.
When I retunred to the freight business in 2008 after a long hiatus, in a DHL distribution center, one new tactic which I was suprised to discover was that producers of small, but high-value or-time-sensitive shipments (custom home computer systems and gift boxes of citrus fruit were two overy common items) would ship a large numbr of orders to the same region via a common- or contract-carrier trucker, then let UPS, FedEx or DHL handle the local delivery.
So i wouldn't look for rail carriers to get in on almost any of this business soon. What might be possible, hovever, would be the recapture of the carload-size shipments of perishable (I. E: dressed meat and produce), merchandise, and occasional (I. E: specialty steel) shipments .... if the infrastructure can be rebuilt and sufficiently fine-tuned.
What a revoltin' development this is! (William Bendix)