The 1975–1979 corpus splits cleanly into two distinct imaginaries about personal transportation in 2025 — and the gap between them is more revealing than either vision alone.

O'Neill's The High Frontier imagines transportation as a solved engineering problem, elegant and nearly free. The "commutersphere" and "travelsphere" require no engines, no fuel, no crew — just the angular momentum of rotating habitats and the vacuum of space doing the work. "Such transportation should be quite inexpensive, because it will require no energy. That sounds vaguely disquieting, rather too much like perpetual motion, but in fact the statement is true." O'Neill's transportation future is frictionless in every sense: physical, economic, social. A couple takes a half-hour flight to dinner in another habitat — culturally as distant as Rome from Kansas City — for less than the cost of a short car trip on Earth. The maglev, the commutersphere, the travelsphere: all are imagined as abundance technologies, democratizing movement across what are essentially planetary-scale distances.

Adlard's Multiface, set in a stratified future city, imagines something closer to what 2025 actually delivered: electric vehicles that are real but expensive, tiered by class, navigated through bureaucratic complexity. Will studies "How To Drive An Auto" for months, poring over a map of the Autocomplex between the First and Second Sectors — "an island which dozed like a bloated spider in the middle of a web too intricate for unravelling" — and is frightened merely to look at it. The electric autos are silent and clean, yes, but access to the good ones costs "all his increments for two months." Adlard got the technology roughly right (electric, quiet, autonomous-adjacent) but more importantly got the social texture right: the technology exists, stratified access to it is the actual problem.

Weizenbaum, writing not as a futurist but as a critic, cuts through both visions with a sharp historical observation: computers were used to automate automobile production lines "so that people could choose from among millions of trivial options on their new cars" rather than to downgrade private automobiles in favor of mass transit. He names the road not taken — "perhaps the private automobile could have been downgraded as a means of personal transportation in favor of mass transit in, and passenger rail between, the cities" — and frames it as a choice that was made, not a technical inevitability. Standing in 2025, this reads as prophecy: the US has more car models than ever, EVs are the new "trivial options," and mass transit remains chronically underfunded in most American cities.

Clarke in The View from Serendip makes the most interesting bet: that communications would substitute for transportation. "Men do much less commuting, much more communicating." He imagined the city beginning to die as the "comsole" made physical presence optional. He was half right, in a way he couldn't have anticipated — the pandemic briefly validated his model, remote work restructured some commuting patterns — but the city didn't die, and personal transportation demand didn't collapse. What he missed is that cheap communication and cheap transportation turned out to be complements, not substitutes. People used connectivity to arrange more movement, not less.

[O'Neill, The High Frontier, 1977] contributes the optimist engineering imagination — transportation as physics problem, solvable by ingenuity, yielding abundance. His maglev and commutersphere passages are doing real technical work, not hand-waving: he correctly identifies magnetic levitation as a high-vacuum technology and notes that Earth's atmospheric drag is the actual obstacle. What he couldn't see was that the political and economic infrastructure to build even terrestrial maglev would stall for half a century. Japan's SCMaglev line opened revenue service in 2027 in his imagined future; in our 2025, it's still not carrying passengers.

[Adlard, Multiface, 1975] is the corpus's sharpest hit. Silent electric vehicles, credit-card-activated hire systems, autonomous navigation ("the auto fled into the round black mouth of a tunnel... the headlights came on automatically"), tiered access by class, and the bureaucratic nightmare of the interchange — all of this maps onto 2025 with uncomfortable precision. The detail of Jan's car running "200,000 kilometres and no maintenance" with gas turbines "in total silence" is the one significant miss: we got battery EVs rather than turbines, and maintenance hasn't vanished. But the social architecture — expensive vehicles as class markers, complex interchange systems, electric propulsion — landed.

[Weizenbaum, Computer Power and Human Reason, 1976] contributes the political economy lens that O'Neill entirely lacks. His observation that the automobile's dominance was a choice enabled by computing — not a natural outcome of consumer preference — reframes the whole picture. In 2025, this reads as the most accurate analysis in the corpus: autonomous vehicle technology has been used to produce more sophisticated individual cars, not to reorganize transportation around shared infrastructure.

[Clarke, The View from Serendip, 1977] contributes the substitution hypothesis — communications replacing transportation — and the infrastructure-inertia observation: "The road and rail systems will still be basically the same... these features of our civilization involve such gigantic investments of capital, material, and labour that, even with the strongest incentives, it requires decades to make substantial changes." This second insight landed perfectly. The first — that communication would kill the city — partially arrived fifty years late and only under pandemic duress.

The arc across this five-year window (1975–1979) runs from technological optimism toward social critique, with Adlard occupying the uncomfortable middle ground of dystopian realism. O'Neill's space-habitat transportation is the purest expression of the era's engineering confidence: given the right physical substrate, transportation becomes nearly free and universally accessible. Clarke's communications-substitution thesis is a gentler version of the same optimism — technology solves the problem of distance, making transportation itself less necessary. Weizenbaum and Adlard break from this in opposite directions: Weizenbaum by arguing that technology choices are political choices, Adlard by dramatizing what happens when the technology arrives but the class structure that preceded it remains intact.

What none of these texts could see — the genuine blind spot of the era — is network platform capitalism as a transportation model. Uber, Lyft, autonomous vehicle fleets operated by tech companies: the idea that personal transportation would be reorganized not by public infrastructure or private ownership but by algorithmic dispatch from private platforms is simply outside the imaginative horizon of 1975–1979. O'Neill imagines public infrastructure in space; Adlard imagines tiered private hire; Weizenbaum imagines public transit as the alternative. None imagines the gig-economy driver, the surge-pricing algorithm, the venture-capital-subsidized ride that costs less than its actual price.

This configuration has real gaps. The seven-book corpus skews heavily toward Anglo-American and European male voices — O'Neill the physicist-engineer, Weizenbaum the computer scientist, Clarke the techno-optimist, Adlard the British literary SF writer. What's missing is any transportation imagination from the Global South, where in 2025 the actual transportation story is often more interesting: motorcycle taxis, minibus networks, mobile-payment-enabled transit in cities that never built the car-dependent infrastructure that Western writers took as baseline. The corpus cannot see Lagos or Nairobi or Shenzhen because it cannot imagine that those cities would be the transportation laboratories of 2025.

The lens also can't resolve the body inside the vehicle — disability, aging, the question of who benefits when transportation becomes automated. Adlard comes closest, dramatizing class access, but even his critique is about economic stratification rather than the full range of human needs that transportation systems either serve or exclude. And the retrieved passages, while rich on the futurist and critical side, have thin coverage of the actual fiction of movement — the experience of being in transit, the texture of the commute — which is where transportation most shapes daily life.