The Economist: Colombia’s infrastructure: Bridging the gaps: “Its route includes an unpaved track that locals call the “trampoline of death”, running from Pasto, capital of the Nariño department, to Mocoa in the Andean foothills. “

Reihan Salam – The Agenda: A Few Thoughts on the Great Relocation Thesis :

“Noah Smith has written a post on what he calls the “Great Relocation.” I recommend reading it, in part because I’m going to skip summarizing his argument. I agree with most of Smith’s prescriptions, e.g., an increase in high-skilled immigration, promotion of urban density, investment in infrastructure, lowering trade barriers, etc. I’ll focus on disagreements.
(1) Smith refers to the “nonsensical anti-train animus” of conservatives. As a fan of rail, I think it is safe to say that I have no nonsensical anti-train animus. I am, however, wary of the nonsensical pro-train sentiments of some non-conservatives, who assign quasi-mystical powers to high-speed rail. As George Monbiot has observed, many of the environmental claims advanced on behalf of HSR are overblown, particularly when we factor in the carbon-intensive process of manufacturing rolling stock. I am not averse to sustainable HSR that requires limited public subsidy, but like Stephen Smith of Market Urbanism I tend to think that cost-effective investments in medium-speed rail are a more sensible first step. 
Moreover, I often think that nonsensical pro-train sentiments flow from a failure of imagination. If Stanford’s Sebastian Thrun succeeds in fostering the widespread adoption of self-driving cars, we could radically reduce the congestion and energy costs associated with personal vehicles. The CityCar concept advanced in Reinventing the Automobile could make dense urban areas far more energy efficient while medium-range inter-city distances could be traversed by “trains” of personal vehicles that are made available via sophisticated sharing platforms and that move at least as quickly as the Acela. The advantage of these pseudo-trains is drivers could stop and start their journeys at any time and at any given place on an extensive road network.
Rail has the great advantage of being able to haul heavy goods at a relatively low energy cost, which is why the rail freight business has proven so successful. But people are very light. The Federal Railroad Administration mandates that passenger trains be far heavier than is strictly necessary, which swells the costs of domestic passenger rail projects. It is also true that sophisticated collision detection systems will allow us to build lighter personal vehicles, thus reducing their energy costs as well.
Projecting today’s transportation technologies into the future is, in my view, a mistake. Smith references Cowen’s thesis (by way of Peter Thiel) that transportation technology has been stagnant in recent decades, which is true enough, particularly if we use speed as our sole metric. But my view is that the rise of “the mesh,” i.e., of sophisticated Internet- and GPS-enabled sharing platforms, represents a significant step forward in transportation, and that the advent of self-driving cars and “intelligent roads” will deliver impressive productivity gains.” …

Prestressed Concrete brings us this movie: Paving the road of the future.