The 1975–1979 corpus splits cleanly into two imaginative registers when it comes to personal transportation in 2025, and the gap between them is the most revealing thing in the passages.

O'Neill's The High Frontier builds an entire transportation ecology for space habitats — maglev "magneplanes" threading through vacuum at 300 mph, engineless "commuterspheres" coasting between cylinders on pure orbital mechanics, "travelspheres" crossing intercontinental distances for a fifth the cost of a jet ticket. The engineering is specific, even affectionate. He quotes Clarke on zero-gravity toilets. He calculates amortization schedules. He imagines young people hopping between habitats with snow skis or water skis "for no more than the cost of a bus token." This is transportation as liberation — from petroleum, from noise, from cramped aircraft, from the tyranny of timetables.

Weizenbaum, writing the same year, looks at the same automobile civilization and sees something entirely different: a system of manufactured desire. His passage in Computer Power and Human Reason argues that the computer was used to automate production lines so people could "choose from among millions of trivial options on their new cars" — when the actual alternative, mass transit and passenger rail, was always available and was simply never chosen. He's not describing a failure of technology. He's describing a failure of imagination institutionalized by capital.

Adlard's Multiface, set in a future Britain that maps onto our present, threads between these poles. His electric autos — silent, gas-turbine-free, requiring recharging at "Autoterminus" stations — got the direction right. But they remain individually operated, status-stratified (the cheapest is a "rectangular black box with a wheel at each corner" and no doors; the most expensive looks "like a spaceship on wheels" and costs two months' wages for a one-way trip), and embedded in a road infrastructure so complex that the map of the "new Autocomplex" between city sectors resembles a spider's web that "frightened Will merely to look at." The technology changed. The social logic didn't.

Clarke's The View from Serendip makes the most prescient move, though obliquely: he predicts that communications technology will reduce the need for commuting, that executives could do ninety percent of their work without leaving home, and that this might eventually kill the city. He frames this as transportation's replacement, not its reform. He got the mechanism right (the "comsole" is a smartphone plus Zoom) but misjudged the consequence — cities didn't die; they became more expensive, and the people who could work from anywhere moved to them anyway.

[O'Neill, The High Frontier, 1977] contributes the most elaborated positive vision — and the most revealing displacement. O'Neill's transportation utopia is off-Earth. The maglev works in vacuum. The travelsphere works without atmosphere. The commutersphere works because space habitats rotate at exactly the right speed. Every elegant solution depends on leaving the planet first. This is the era's deepest assumption about personal transportation: that Earth's problems (petroleum dependence, congestion, noise, pollution) were insoluble here, and that the only way to get the transportation system we deserved was to build it somewhere else. Forty-seven years later, we're still on Earth, still arguing about high-speed rail.

[Weizenbaum, Computer Power and Human Reason, 1976] provides the critical counterweight. His observation that "the people's cultivated and finally addictive hunger for private automobiles" could have been redirected toward mass transit — but wasn't, because computers were used to serve the existing industrial logic rather than challenge it — reads in 2025 as a precise description of how autonomous vehicle technology has been deployed. We got computational power in cars. We got it used to add features, not to replace the car.

[Adlard, Multiface, 1975] is doing the most interesting fictional work. His future London has electric vehicles, automated navigation (the car follows a "buried wire" home at walking speed), and a class system encoded in vehicle choice. The executive Jan rides in silence through the Channel Tunnel, his gas turbine running without vibration after 200,000 kilometers, nostalgically pitying the old combustion-engine drivers. The laborer Will stares at the "How To Drive An Auto" booklet, terrified by the road map. Electric, yes. Equitable, no. Adlard saw the technology transition and the social stratification that would survive it.

[Clarke, The View from Serendip, 1977] contributes the substitution thesis — that communication would replace transportation — and the infrastructure inertia argument: "The road and rail systems will still be basically the same" in 1992, he writes, because capital investments in physical infrastructure take decades to change. Both observations are correct for 2025. The roads are basically the same. Remote work exists but didn't kill the commute; it bifurcated it.

The arc across these texts moves from transformation to persistence. O'Neill imagines transportation fundamentally reinvented — new physics, new infrastructure, new social relations around movement. Weizenbaum argues the existing system is self-reinforcing and will resist reinvention. Adlard depicts the midpoint: surface transformation (electric, quiet, computerized) over unchanged social bones. Clarke predicts the bypass — communication as transportation's substitute — which partially arrived but didn't produce the predicted consequence.

What inflects across the window is confidence. The mid-1970s authors writing about space (O'Neill, Clarke) still believe in the possibility of genuinely new infrastructure. The authors writing about Earth (Weizenbaum, Adlard) have absorbed the lesson of the postwar American city — that technology serves whoever controls capital, not whoever needs mobility. By 1979, the hopeful visions are all set off-planet. The Earth-bound visions are either critical or resigned.

This slice of the corpus is almost entirely male, almost entirely British and American, and almost entirely focused on the engineering of transportation rather than its politics. Nobody in these passages asks who owns the infrastructure, who is excluded from it, or how transportation connects to land use, zoning, and housing. Adlard gestures at class stratification in vehicle access, but doesn't follow it into the neighborhood — into the question of who can afford to live near the magneplane station in the first place.

The collection also has no Global South perspective on personal transportation, which by 2025 is where the most consequential developments are actually happening — the motorcycle-taxi economies of Lagos and Nairobi, the electric-rickshaw transitions in South Asian cities, the ways that cheap two-wheelers and ride-hailing apps have transformed mobility for billions of people in ways none of these authors imagined. Their frame was the wealthy industrial nation. The future they missed was everywhere else.