The 1975–1979 corpus splits cleanly into two incompatible visions of personal transportation in the near future — and the split reveals something the authors themselves couldn't see clearly: they were arguing about the wrong problem.

O'Neill's The High Frontier is the most technically exuberant text in the set. His "commutersphere" and "travelsphere" — engineered spheres launched by magnetic acceleration, requiring no engines, no fuel, coasting on physics alone — represent a genuinely radical reimagining of what transportation is. The key insight: in space, you don't fight atmosphere, gravity, or petroleum scarcity. You use them. A "travelsphere" between colonies costs less per passenger-mile than a 1970s jetliner precisely because it has no engines to run. O'Neill even borrows Clarke's toilet joke to humanize the engineering. This is transportation as infrastructure problem, solved by changing the environment rather than improving the vehicle.

Adlard's Multiface works the opposite angle. Set in a recognizable near-future Britain, his electric autos are already normalized — quiet, battery-powered, recharged at Autoterminuses, tiered by cost from black rectangular boxes without doors to silver spaceship-shaped luxury models. Will's painstaking study of How To Drive An Auto and the terror-inducing Autocomplex map between sectors reads as a dry comedy about class and access — the cheapest auto is barely a car, the expensive one costs two months of increments for a one-way trip. Adlard got electric vehicles right, got tiered access right, even got the complexity of urban interchanges right. What he didn't see: the auto in his world is still a human-driven, individually-hired object. No autonomy, no networking, no ride-share logic.

Weizenbaum is the skeptic. Writing in Computer Power and Human Reason, he doesn't predict what transportation will look like — he diagnoses why it turned out wrong. Computers were used to automate automobile production lines so people could choose "from among millions of trivial options on their new cars" rather than to downgrade the private automobile in favor of mass transit. He names the addiction directly: "the people's cultivated and finally addictive hunger for private automobiles." From 2025, this reads as devastating accuracy — not as prediction, but as structural analysis. The car-as-consumer-product logic he describes in 1976 is precisely what delivered us a world where EVs are marketed with seventeen ambient lighting colors rather than a functional transit network.

Clarke in The View from Serendip takes the longest view and makes the most interesting miss. He argues that improved communications will reduce commuting — that the "comsole" (his name for what is essentially a video-conferencing terminal) will allow executives to conduct ninety percent of business without leaving home, and that this will begin killing the city. He's not wrong about remote work; 2020–2025 proved him remarkably prescient there. But his conclusion — that reduced commuting pressure would allow transportation infrastructure to remain basically unchanged while cities slowly died — underestimated the persistence of urban concentration and missed entirely that communications revolution and transportation demand would both increase simultaneously.

[O'Neill, The High Frontier, 1977] contributes the era's most technically specific transportation vision — and its most revealing failure mode. The magneplane, the commutersphere, the travelsphere: all are real engineering concepts extrapolated carefully. What O'Neill couldn't imagine is that the political and economic infrastructure for space colonization would not materialize on his timeline. His transportation systems are internally coherent but externally dependent on a premise — mass orbital habitation by the early 21st century — that didn't happen. The passages here are doing real work: they show transportation as a solved problem once you accept the habitat premise, which makes the gap between vision and reality entirely about the premise, not the engineering.

[Adlard, Multiface, 1976] is the sleeper text in this configuration. The electric auto ecosystem he describes — tiered by cost, hired by credit card, recharged at terminals, navigated through complex urban interchanges with alphanumeric scanners — is recognizably the world of 2025 Zipcar and EV charging infrastructure, minus autonomous operation. His class analysis of transportation access is sharp: Will can only afford the doorless black box, while executives glide in gas-turbine silence through empty tunnels, the self-profiling seat conforming to their bodies. The gas turbine detail in the executive's auto — "after 200,000 kilometres and no maintenance... ran without vibration and in total silence" — shows Adlard hedging his bets on propulsion technology. He got the social stratification of personal transport right while splitting the difference on the technology.

[Weizenbaum, Computer Power and Human Reason, 1976] contributes the sharpest structural critique, though transportation is not his primary subject. His argument that computers were deployed to maximize automobile variety rather than transportation utility — enabling millions of trivial options rather than enabling alternatives to the private car — reads from 2025 as a precise description of how Tesla markets the Model S. He saw the political economy of the choice clearly; he just couldn't see that the addiction would survive the transition from petroleum to electrons.

[Clarke, The View from Serendip, 1977] provides the communications-transportation nexus. His prediction that telecommuting would reduce transportation demand was correct in mechanism, wrong in magnitude and consequence. He also makes an interesting offhand prediction about road and rail systems remaining "basically the same" through the 1990s — accurate — while hoping American cities would develop subways "nearly as good as those which Parisians and Londoners have enjoyed." Still waiting.

The arc across these texts runs from replacement to stratification. O'Neill imagines transportation problems replaced by better physics in a better environment. Adlard and Weizenbaum imagine the existing transportation logic persisting but stratifying — better vehicles for those who can afford them, the same basic car-dependency for everyone else. Clarke imagines transportation demand declining as communication substitutes for physical movement.

The inflection point the corpus cannot see but 2025 can: all three patterns happened simultaneously, in different economic strata. O'Neill's vision materialized for billionaires (SpaceX, private aviation, yacht culture). Adlard's stratified EV world materialized for the middle class. Weizenbaum's warning about trivial options materialized for mass-market consumers. Clarke's telecommuting reduction materialized for knowledge workers — but it didn't kill transportation demand, it redistributed it to delivery networks and leisure travel. The 1970s authors were each right about a different slice of 2025.

This configuration has two significant gaps. First, the corpus is entirely male and largely Anglo-American, which shapes the transportation imagination in ways that are hard to see from inside it. The "commuter" in O'Neill, the "executive" in Adlard, the automobile "addict" in Weizenbaum — these are assumed to be men with jobs in fixed locations, traveling between home and workplace on predictable schedules. The transportation futures imagined here don't grapple with the mobility needs of caregivers, the geography of poverty, or the transportation patterns of the Global South. Adlard's class analysis gets closest, but it's still contained within a single city's sector system.

Second, none of these texts anticipate the platform economy of transportation — the idea that the vehicle itself becomes less important than the network coordinating vehicles. Uber, Lyft, autonomous vehicle fleets, drone delivery: these represent a transportation logic where ownership and operation are separated, where the "personal" in personal transportation dissolves into on-demand access. Weizenbaum comes closest by noting how computers were used to serve existing automobile industry logic rather than challenge it — but even he couldn't see that the next disruption would come not from changing the vehicle but from changing who owns and dispatches it. The retrieved passages have no vocabulary for platform-mediated mobility, which may be the single largest structural feature of 2025 personal transportation that this entire corpus missed.