The 1975–1979 corpus splits almost perfectly along a fault line that only becomes visible from 2025: the difference between imagining new infrastructure and imagining new relationships with infrastructure. O'Neill's "travelsphere" and "commutersphere" are engineering proposals dressed as fiction — frictionless, energy-free vehicles launched by habitat rotation, maglev trains humming through vacuum tunnels, the whole apparatus premised on abundant cheap electricity and centralized computer control [O'Neill, The High Frontier, 1977]. Adlard's Tcity, by contrast, imagines electric autos available for hire at terminals, requiring a credit card and a ticket and a baffling interchange map — class-stratified, bureaucratically mediated, and fundamentally anxiety-producing for anyone who didn't grow up with it [Adlard, Multiface, 1975]. Both visions arrived in 2025. We got Adlard's friction, not O'Neill's frictionlessness.

What neither author fully anticipated was the degree to which the interface would become the vehicle. O'Neill imagines computer control as background infrastructure — the habitat's computer waits for the right moment in the rotation cycle and unlocks the commutersphere. Adlard imagines alphanumeric scanners and credit card slots. Neither imagines that the most consequential transportation technology of 2025 would be the smartphone app mediating between a person and a driver, or the GPS routing system that has restructured urban geography more thoroughly than any new road. The vehicle itself — electric, relatively quiet, increasingly capable of partial self-navigation — arrived roughly as imagined. The layer on top of it was invisible to both.

Weizenbaum's contribution is the sharpest retrospective read. Writing in 1976, he diagnoses the automobile not as a transportation technology but as a political choice that computers were used to entrench rather than challenge: "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. But the computer was used to automate the flow of parts to automobile production lines so that people could choose from among millions of trivial options on their new cars" [Weizenbaum, Computer Power and Human Reason, 1976]. This is exactly what happened — and then happened again. The next wave of computing was used not to build the mass transit alternative but to optimize ride-hailing on top of the existing car-dependent infrastructure, producing Uber and Lyft as the logical descendants of Weizenbaum's "millions of trivial options." The critique anticipated the pattern; it could not prevent its repetition.

Clarke's mobile autonomous home — carried by sky crane, untethered from pipes and power lines, enabling whole communities to migrate seasonally — is the most spectacular miss in the corpus, and the most revealing one [Clarke, The View from Serendip, 1977]. It assumes that personal transportation would scale up to the dwelling unit itself, that the freedom the automobile gave would compound into total spatial freedom. What actually happened is the inverse: housing became less mobile, more expensive, more fixed, while personal vehicles became cheaper and more numerous, producing not liberation but the commute. The sky crane carrying your house to Arizona remained a fantasy; the two-hour traffic crawl into Phoenix became reality.

[O'Neill, The High Frontier, 1977] contributes the engineering-optimist pole. His transportation vision is internally consistent and genuinely interesting: the commutersphere requires no engine because it uses the habitat's existing rotation energy; the magneplane works in vacuum where aerodynamic drag doesn't apply. These aren't wild fantasies — they're correct applications of physics to a context that didn't materialize. What O'Neill cannot imagine is that the context itself (the space habitat) might not arrive, leaving his transportation innovations without a substrate. His vision of commuters setting "their electric vehicles to find their way home along the bicycle paths at a safe walking speed, following the magnetic lure of a buried wire" is strikingly close to autonomous vehicle concepts — but embedded in infrastructure that doesn't exist.

[Adlard, Multiface, 1975] does the heaviest lifting for the present reality. The electric hire-auto with its credit card scanner, its terminal system, its class gradient (the cheapest model is a rectangular black box without doors; the most expensive looks like a spaceship on wheels and costs two months' increments for a one-way trip), and its incomprehensible interchange map — this is recognizably the world of car-sharing apps, congestion pricing, and the spatial anxiety of navigating a city designed around a vehicle system you don't fully control. Will's struggle with the Autocomplex map, "an island which dozed like a bloated spider in the middle of a web too intricate for unravelling," reads as a precise emotional description of trying to navigate a highway interchange in an unfamiliar city. Adlard also gets the gas turbine's obsolescence right: his future vehicles run in near-silence, and his character Jan nostalgically imagines "piston engines vomiting carbon monoxide" as a thing of the barbarous past.

[Weizenbaum, Computer Power and Human Reason, 1976] provides the analytical frame the other texts lack. He's not imagining future transportation — he's diagnosing how computing was being used to preserve existing transportation arrangements rather than transform them. The passage about "addictive hunger for private automobiles" being satiated with trivial options rather than genuine alternatives reads, from 2025, as prophecy about the entire subsequent history of automotive computing: navigation systems, infotainment, semi-autonomous features, all optimizing the private automobile experience rather than replacing the private automobile.

[Clarke, The View from Serendip, 1977] contributes the communications-as-transportation-substitute argument that half-landed. His prediction that improved communications would reduce commuting — "men do much less commuting, much more communicating" — was structurally correct but temporally scrambled. Remote work did eventually arrive as a mass phenomenon, but it took a pandemic rather than the gradual build-out of home communications consoles Clarke imagined, and its transportation effects (dispersal from city centers, longer commutes for those who still commute, increased driving in secondary cities) were not what he predicted.

The 1975–1979 window sits at a specific historical hinge: the oil crisis had just made the energy cost of private transportation visible for the first time, which is why every author in the corpus reaches for electric vehicles, maglev, and energy-free transit as obvious solutions. O'Neill's repeated emphasis that the travelsphere "requires no energy" and runs on "unlimited low-cost electrical energy" reflects the anxieties of 1977 as much as the physics of space habitats. The electric vehicle these authors imagined has arrived — but the energy politics around it remain as contested as ever, which none of them fully anticipated.

The deeper pattern is a consistent failure to imagine network effects on transportation. O'Neill imagines better vehicles. Adlard imagines better-administered vehicles. Clarke imagines vehicles becoming unnecessary. None of them imagine that the most transformative transportation development of the next fifty years would be coordination — the ability to match a rider with a driver in real time, to route millions of vehicles simultaneously, to make the aggregate behavior of the transportation network legible and manipulable. The vehicle was the figure; the network was the ground. Every author stared at the figure.

The corpus is almost entirely white, male, and British or American, which shapes its transportation imagination in specific ways. There's no engagement with the transportation realities of the Global South, where the most consequential personal transportation developments of the subsequent decades — the motorcycle taxi, the minibus, the tuk-tuk, the mototaxi app — would emerge from necessity rather than engineering ambition. O'Neill's travelspheres and Adlard's electric autos both assume a built infrastructure of terminals, guideways, and power points; they cannot imagine transportation that works around infrastructure failure rather than through infrastructure excellence.

The corpus also has almost nothing on the body in transportation — disability, aging, the specific ways that transportation systems exclude or include people based on physical capacity. Adlard's Will struggles with the Autocomplex map cognitively, but the physical experience of the vehicle is treated as neutral. The accessibility revolution in transportation — kneeling buses, wheelchair ramps, audio navigation — is entirely outside this frame. And the retrieved passages skew heavily toward O'Neill and Clarke, both infrastructure optimists; a corpus with more dystopian or critical voices from this period might have surfaced the transportation-as-control angle that only Weizenbaum partially develops.