Argue both sides of free buses: every AI model's reply, tested

In two paragraphs of at most 90 words each, first argue that a city should make its buses free, then make the strongest case against it. The second paragraph must be as persuasive as the first. No headings.

Exactly what this prompt's replies are checked against, with every other prompt of our test runs.

1. GLM 5.3 Flash

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 92 words, over the 90 allowed.

   Free buses would transform the city overnight. Ridership would surge, cutting congestion, pollution, and parking demand as drivers leave their cars behind. Low-income residents, who spend the largest share of income on transportation, would gain real mobility—reaching jobs, schools, and clinics without a fare standing in the way. Fare collection itself costs money; eliminating it speeds boarding, simplifies routes, and lets drivers focus on driving. A city that believes in its future should treat transit as what it truly is: public infrastructure, free at the point of use.
   
   Yet free buses carry real costs that fall hardest on those who need service most. Without fare revenue, budgets strain, forcing route cuts and infrequent service—fewer buses help riders far less than cheaper ones. Free fares do nothing to expand capacity, so overcrowded routes stay overcrowded while money that could fund new lines vanishes. Studies of fare-free systems show many new riders previously walked or cycled, not drove, so congestion barely improves. Better to charge riders and reinvest every dollar into frequency, coverage, and reliability—the things that actually make transit worth taking.

   399 tokens in, 237 out (9 of them reasoning) · 11.2 s · $0.0001 · 1 message on Pro · answered by z-ai/glm-5.3-flash via AtlasCloud · September 27, 2026

2. Claude Haiku 5.5

   Failed: Graded 4.0 of 5 on average (lowest 4); but a paragraph of 103 words, over the 90 allowed.

   Free buses would remove the single biggest barrier to public transit: the fare itself. For low-income residents, fares consume a meaningful share of income, and free service means no one is forced to choose between a bus ride and groceries. Fare collection also slows boarding, and eliminating it speeds routes and improves reliability for everyone. Ridership tends to rise, which eases traffic, cuts emissions, and reduces the need for parking. Administrative costs of ticketing, enforcement, and fare evasion disappear too. Compared with the cost of building roads and subsidizing cars, funding buses directly is a cheap way to give every resident reliable mobility.
   
   Free buses would divert public money from needs that matter more. Fare revenue, though often modest, funds service, and replacing it with taxes shifts costs onto everyone, including people who rarely ride. Free rides also tend to be used most by those who already have options, so the benefit may be less targeted than advocates claim. Without price signals, demand can outstrip capacity, leading to crowding and degraded service. Cities could instead offer fare discounts or subsidies for low-income riders, which target help precisely. Fixing frequency, safety, and maintenance would likely attract more riders than zero fares, and those dollars would stretch further.

   521 tokens in, 412 out · 3.3 s · $0.0003 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

3. GLM 5.3

   Failed: Graded 3.7 of 5 on average (lowest 3); but a paragraph of 92 words, over the 90 allowed.

   A city should make its buses free because the benefits ripple far beyond riders. Fare-free transit boosts ridership immediately, cutting car trips, congestion, and emissions while improving air quality. It saves low-income residents money, connects workers to jobs, students to schools, and seniors to care, and it eliminates fare enforcement disputes that disproportionately harm marginalized riders. Fares often recover only a modest share of operating costs anyway, so removing them trades a small revenue stream for a faster, fairer, more accessible city — a genuine public good like roads and libraries.
   
   Yet free buses carry real costs that advocates understate. Fare revenue funds service; eliminate it and the burden shifts to taxpayers, many of whom never ride, straining budgets already stretched thin. Free buses can overload the system — especially with vulnerable riders seeking shelter — degrading the experience for commuters who depend on reliability. Fare-free transit can also reduce pressure to improve service quality, since riders are no longer paying customers with leverage. And studies suggest it mainly attracts walkers and cyclists, not drivers, doing little for climate. There's no free lunch: someone pays.

   422 tokens in, 234 out (11 of them reasoning) · 1.8 s · $0.0013 · 1 message on Pro · answered by z-ai/glm-5.3 via Wafer · September 27, 2026

4. Gemini 4 Argon

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 91 words, over the 90 allowed.

   Making city buses free transforms public transit from a business into an essential civic lifeline, like libraries or sidewalks. Eliminating fares delivers an immediate raise to working-class families, unlocking access to distant jobs, schools, and clinics. Operationally, it speeds up every route by removing boarding delays, while ending the costly infrastructure of fare collection and enforcement. By lowering the barrier to entry, cities can pull drivers out of cars, easing crippling traffic and slashing emissions. Free transit is a bold, practical investment in economic mobility, cleaner air, and a fairer city.
   
   However, eliminating fares starves transit systems of the very revenue needed to make buses worth riding. Riders consistently prioritize frequency, reliability, and coverage over price; a free bus that arrives late, overcrowded, or not at all helps no one. Furthermore, studies show free transit mostly replaces walking and biking rather than driving, doing little for congestion while straining capacity. Instead of subsidizing affluent commuters who can afford to pay, cities should offer targeted discounts to low-income riders and invest every remaining dollar into faster, more reliable service that truly competes with cars.

   628 tokens in, 226 out · 7.0 s · $0.0018 · 1 message on Pro · answered by google/gemini-4-argon via Google AI Studio · October 15, 2026

5. Grok 4.7

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 100 words, over the 90 allowed.

   A city should make its buses free because fare collection costs money, slows boarding, and keeps poorer riders off the system. Zero fares would cut those overheads, fill empty seats, and turn transit into a genuine public service rather than a paywall. Riders who switch from cars would ease congestion and pollution, while workers, students, and elderly residents would gain reliable mobility without budgeting for every trip. The social return—fewer missed shifts, wider access to jobs and clinics, a more livable street—outweighs the lost ticket revenue if the city funds the gap from parking fees or a modest local tax.
   
   Free buses fail when they are treated as a gift rather than a service that must still run on time. Without fares, demand surges while revenue collapses, so agencies cut frequency, defer maintenance, and pack vehicles until riding becomes slower and less safe than driving. Crowding and disorder drive away the very commuters whose fares once subsidized off-peak routes, and taxpayers who never ride absorb a growing bill with no accountability for performance. A cheap fare, paired with faster boarding and more buses, keeps the system solvent and trustworthy; abolishing the price does not create capacity, and a free bus that does not come is worthless.

   1,619 tokens in, 307 out (54 of them reasoning) · 6.0 s · $0.0034 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

6. Claude Sonnet 5.5

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 98 words, over the 90 allowed.

   Free buses make a city fairer, faster, and greener. Fares are a regressive tax on people who can least afford them, and dropping them instantly raises effective income for low-wage workers, students, and seniors. Boarding without payment cuts dwell time, so routes run quicker and more reliably. Cities that tried it, like Kansas City and Dunkirk, saw ridership jump, taking cars off congested streets and lowering emissions. Fare collection also eats money: machines, enforcement, and administration can consume a large share of what fares bring in. Free transit turns buses into a public good, like roads and libraries.
   
   Free buses sound generous but quietly damage the service riders depend on. Fares provide a dependable revenue stream, and replacing it means higher taxes or budget cuts elsewhere, often leaving transit chronically underfunded. Money is better spent on frequency, reliability, and coverage, which matter more to low-income riders than a zero fare. Much of the new ridership comes from people who would have walked or cycled, not drivers, so climate gains are modest while crowding worsens. Targeted discounts help the poor directly without subsidizing every rider, including wealthy commuters, and keep agencies accountable to the people they serve.

   522 tokens in, 401 out · 4.4 s · $0.0051 · 1 message on Pro · answered by anthropic/claude-sonnet-5.5 via Anthropic · September 28, 2026

7. Gemini 3.1 Pro

   Failed: Graded 3.7 of 5 on average (lowest 3).

   Making city buses free is a powerful catalyst for economic equality and environmental sustainability. By eliminating fares, cities immediately remove a significant financial burden from low-income residents, improving their access to jobs, education, and healthcare. Furthermore, free transit incentivizes people to leave their cars at home, dramatically reducing traffic congestion and cutting harmful greenhouse gas emissions. This shift not only improves urban air quality but also reduces the long-term wear and tear on city infrastructure, ultimately creating a cleaner, fairer, and more accessible environment for all residents.
   
   However, eliminating fares fundamentally undermines the financial stability and quality of the transit system itself. Fares provide crucial revenue required for essential maintenance, route expansion, and driver salaries. Without this income, cities are forced to either slash service frequencies and coverage or drastically raise local taxes to cover the deficit. Consequently, free transit often results in overcrowded, unreliable, and dilapidated buses. Passengers ultimately prioritize speed, safety, and reliability over zero cost; a free bus is useless to a commuter if it never arrives on time.

   409 tokens in, 699 out (492 of them reasoning) · 9.1 s · $0.0092 · 1 message on Pro · answered by google/gemini-3.1-pro-preview via Google · September 27, 2026

8. Claude Fable 5.1

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 99 words, over the 90 allowed.

   Free buses remove the single biggest barrier to ridership: the fare. Every boarding becomes faster with no payment friction, cutting dwell times and making service more reliable. Low-income residents, who spend a disproportionate share of income on transport, gain immediate relief, expanding access to jobs, schools, and healthcare. More riders mean fewer cars, less congestion, and cleaner air for everyone. Fare collection itself costs money—equipment, enforcement, cash handling—that could be redirected to service. Cities like Kansas City and Tallinn show ridership rises and communities benefit.
   
   Fares typically cover a meaningful slice of operating costs, and abolishing them creates a permanent hole that must be filled by taxes or, more often, by cutting service. Riders consistently say they want frequency and reliability more than free trips; a bus that comes every eight minutes is worth more than one that's free but comes every thirty. Free systems in practice draw riders from walking and cycling, not from cars, so climate gains are marginal. Overcrowding, vandalism, and buses used as shelters have strained free networks. Targeted discounts for those in need deliver equity without sacrificing service quality.

   520 tokens in, 388 out · 9.3 s · $0.0246 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic · September 27, 2026

9. Claude Opus 5.5

   Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 93 words, over the 90 allowed.

   Free buses turn public transit into what it should be: a public good, like sidewalks or streetlights. Fare collection often recovers only a small share of operating costs, yet it slows boarding, requires costly equipment, and deters the riders who need buses most. Remove fares and ridership climbs, as Kansas City and Tallinn saw, easing congestion and cutting emissions. Low-income workers gain hundreds of dollars a year, drivers stop policing payments, and buses move faster. A city that funds roads without tolls can surely fund buses without fares.
   
   Free is not the same as good. Fares fund service, and losing them forces a choice between tax hikes and cuts to frequency, reliability, and coverage, which are the things riders say they want. Studies of fare-free systems find many new riders were pedestrians and cyclists, not drivers, so congestion and emissions barely budge. Some cities report more disruptive incidents, driving away commuters. Low-income riders are better served by targeted discounts, while the revenue preserved buys more buses, more routes, and shorter waits. A bus that never comes is worthless at any price.

   520 tokens in, 2,109 out (1,746 of them reasoning) · 22.5 s · $0.0443 · 1 message on Pro · answered by anthropic/claude-opus-5.5 via Claude Platform on AWS · September 27, 2026

10. GPT-6 Luna

    Passed: Graded 4.3 of 5 on average (lowest 4).

    Making buses free would give every resident reliable access to jobs, school, health care, and daily necessities, regardless of income. It would also speed boarding, reduce fare-enforcement costs, and encourage people to leave cars at home—easing congestion, pollution, and parking pressure. A city that treats public transit as essential infrastructure, rather than a service people must qualify to afford, can build a more connected and equitable community.
    
    But “free” buses still have to be paid for, and the bill could divert money from more urgent improvements: frequent service, safer stops, cleaner vehicles, and routes to underserved neighborhoods. If buses remain slow, crowded, or unreliable, removing fares may do little to persuade drivers to switch, while reducing funds that could make transit genuinely useful. Targeted fare assistance can protect riders who need it most without subsidizing every trip, including those by people who can readily afford to pay.

    384 tokens in, 186 out · 2.5 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

11. DeepSeek V4 Pro

    Passed: Graded 4.7 of 5 on average (lowest 4).

    Making buses free turns public transit into a true public good, like sidewalks or libraries. It removes fares as a barrier for low-income riders, boosts ridership, cuts traffic congestion and emissions, and speeds boarding by eliminating payment delays. Cities already subsidize most transit costs; dropping the small fare share is a modest investment with outsized returns in mobility, equity, and cleaner air.
    
    The strongest case against free buses is that fares, however small, are the only direct signal of demand. Removing them invites overcrowding on popular routes while doing nothing to expand service where it is sparse. Scarce transit dollars are better spent on frequency, reliability, and coverage—improvements that actually attract riders—than on subsidizing trips for people who can already afford to pay.

    395 tokens in, 193 out (40 of them reasoning) · 4.1 s · $0.0009 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 8, 2026

12. DeepSeek V4.1 Flash

    Passed: Graded 4.3 of 5 on average (lowest 4).

    Free buses make a city fairer and faster. Fares cost more to collect than they raise, so abolishing them saves money while filling seats. Riders who now drive will switch, cutting congestion, emissions, and parking demand. Low-income workers gain access to jobs; students and elderly riders gain independence. Downtown shops gain customers. A city that moves everyone freely is safer, cleaner, and more equal. The bus becomes public infrastructure, like a sidewalk — not a toll road.
    
    Free buses are not free; someone pays. Subsidies come from taxes, pulling money from schools, housing, or health. Packed buses with no revenue still need more vehicles and drivers, so service quality falls. Riders who can afford fares — most of them — get a subsidy they don't need, while the poorest may see worse, slower service. Free transit also mostly serves existing riders rather than luring drivers out of cars. Better to fund frequent, reliable buses and discount fares for those who need help.

    423 tokens in, 859 out (655 of them reasoning) · 2.6 s · $0.0011 · 1 message on Pro · answered by deepseek/deepseek-v4.1-flash via Together · October 8, 2026

13. Gemini 3.8 Flash

    Passed: Graded 4.3 of 5 on average (lowest 4).

    Eliminating bus fares instantly dismantles economic barriers for low-income residents, granting equitable access to jobs, education, and healthcare. Free transit slashes household transportation costs while significantly reducing traffic congestion and urban carbon emissions by incentivizing drivers to leave their cars at home. Moreover, removing fare collection speeds up boarding times, which improves route efficiency and eliminates costly ticketing infrastructure. By treating public transit as an essential public good like parks or libraries, a city can revitalize local commerce, curb pollution, and build a more connected, egalitarian community.
    
    However, zero-fare transit starves transit agencies of vital revenue needed to maintain service quality, frequency, and safety. Commuters do not avoid buses primarily because of fares; they avoid them due to unreliability, overcrowding, and long wait times. Eliminating farebox recovery forces cities to divert funding from network expansions or rely on volatile municipal budgets, leading to degraded vehicles and reduced routes. Ultimately, low-income riders suffer most when a "free" system becomes an unusable, neglected service, whereas targeted subsidies and reinvesting fare revenue directly enhance transit for everyone.

    409 tokens in, 220 out · 5.2 s · $0.0011 · 1 message on Pro · answered by google/gemini-3.8-flash via Google · September 27, 2026

14. GPT-6.1 Sol

    Passed: Graded 4.3 of 5 on average (lowest 4).

    A city should make its buses free because mobility is essential infrastructure, not a privilege reserved for those who can afford each trip. Removing fares gives low-income residents immediate access to jobs, schools, healthcare, and community life, while eliminating fare disputes and speeding boarding. If paired with reliable service, free buses can draw people out of cars, easing congestion and pollution. Funding transit broadly recognizes a simple truth: everyone benefits when more people can move freely, whether or not they ride.
    
    But a city should prioritize buses people can depend on over buses that cost nothing. Fare revenue can support frequent service, safe stops, and wider coverage; eliminating it without secure replacement funding risks longer waits and overcrowding. Free access means little when the bus never arrives. Universal subsidies also benefit riders who can comfortably pay, while targeted discounts protect those who cannot. With limited public money, reliable, affordable transit may deliver more opportunity—and attract more drivers—than free but deteriorating service.

    386 tokens in, 195 out · 4.6 s · $0.0014 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 2026

15. Claude Haiku 4.5

    Passed: Graded 4.0 of 5 on average (lowest 4).

    Free buses reduce traffic congestion and emissions while improving public health through increased mobility. They eliminate collection costs and fare evasion losses, funding themselves partly through reduced road maintenance. Equity improves dramatically—low-income residents gain economic mobility and job access. Cities like Luxembourg prove feasibility. The modest expense is offset by economic productivity gains, reduced healthcare costs, and environmental benefits that create long-term savings.
    
    However, free transit strains already limited budgets without guaranteed ridership increases to offset costs. Maintenance deteriorates as systems become overcrowded without capacity expansion funding. Cities risk losing accountability—free services often receive less operational scrutiny. Revenue vanishes precisely when transit needs modernization most. Targeted subsidies for low-income riders prove more efficient than universal free fares. Better solutions include congestion pricing for private vehicles and progressive fare structures, reserving resources for quality service rather than unsustainable giveaways.

    414 tokens in, 195 out · 3.4 s · $0.0014 · 1 message on Pro · answered by anthropic/claude-haiku-4.5 via Amazon Bedrock · September 27, 2026

16. Mistral Large 4

    Passed: Graded 4.0 of 5 on average (lowest 4).

    Free buses remove fares, speed boarding, cut congestion and emissions, help low-income residents, boost the local economy, and treat transit as a public good like roads and sidewalks. Every rider saves money, more people choose buses over cars, streets get safer, and cities can recoup costs through fuel taxes, parking fees, and productivity gains.
    
    Free buses are not free; they shift costs to taxpayers, often through regressive taxes, while fares help fund maintenance and expansion. Zero fares can attract disruptive riders, raise security costs, and reduce service quality as demand outpaces capacity. Wealthy riders benefit most from subsidies, while drivers and businesses still pay for roads. Better to target discounts to those who need them and keep modest fares to preserve reliability, safety, and fiscal discipline.

    391 tokens in, 751 out (650 of them reasoning) · 9.8 s · $0.0018 · 1 message on Pro · answered by mistralai/mistral-large-4-0 via Mistral · October 9, 2026

17. GPT-6 Sol

    Passed: Graded 4.3 of 5 on average (lowest 4).

    A city should make its buses free because a fare can keep people from jobs, classes, and medical appointments. Removing it would make every trip easier, especially for residents with the least money. Boarding would be faster without payment, and some drivers might leave their cars at home, easing traffic and pollution. Funding buses through taxes treats mobility as a public service: everyone benefits when more people can reach what they need.
    
    But free fares are not free service. Fare revenue helps pay for frequent, reliable buses; lose it without secure replacement funding, and riders may face longer waits and crowded routes. Even with new taxes, a city could spend that money on more drivers and better coverage instead. A zero-dollar fare does little for someone whose bus rarely comes. Targeted discounts for low-income riders would protect access while preserving resources to make the service worth taking.

    384 tokens in, 173 out · 4.2 s · $0.0025 · 1 message on Pro · answered by openai/gpt-6-sol via OpenAI · September 27, 2026

18. Kimi K3

    Passed: Graded 4.7 of 5 on average (lowest 4).

    Free buses would transform urban life. Fares raise little revenue after collection costs, yet they deter the very riders—low-income workers, students, the elderly—who depend on transit most. Eliminating them speeds boarding, cuts traffic congestion, reduces emissions, and functions as targeted economic relief for households struggling with costs. Cities like Tallinn and Kansas City show ridership climbs sharply when fares vanish. A city that wants cleaner air, less gridlock, and genuine mobility equity should treat buses like libraries or parks: a public good, free at the point of use.
    
    Yet "free" transit is never free—someone pays, and often it's riders themselves. Forgoing fare revenue means cutting service frequency, deferring maintenance, or raising taxes on residents who never ride. Crowded, deteriorating buses push people back into cars, worsening congestion. Studies show riders value reliability far more than zero fares; a bus that comes every five minutes beats a free one that comes hourly. Scarce funds spent subsidizing middle-class commuters could instead expand routes to underserved neighborhoods. Better to invest in service quality than in a populist gesture.

    471 tokens in, 248 out (11 of them reasoning) · 3.6 s · $0.0049 · 1 message on Pro · answered by moonshotai/kimi-k3 via Together · September 27, 2026

19. Claude Sonnet 5

    Passed: Graded 4.0 of 5 on average (lowest 4).

    Free buses would boost ridership, cut traffic congestion, and reduce emissions by encouraging drivers to switch to transit. Lower-income residents, who rely most heavily on public transportation, would benefit enormously from eliminated fare burdens, improving access to jobs, education, and healthcare. Free transit also simplifies operations, speeding boarding times and eliminating costly fare collection infrastructure. Cities that have tried this, like Kansas City, saw ridership increases and stronger community mobility, suggesting free buses are both an equity tool and a practical urban planning solution.
    
    However, fares provide crucial revenue that funds maintenance, expansion, and service reliability. Eliminating them shifts costs entirely onto taxpayers, straining budgets already stretched thin, potentially forcing service cuts elsewhere. Free buses often attract overcrowding without corresponding investment in more vehicles, degrading service quality for existing riders. Critics also note that the poorest riders may already receive subsidized passes, making universal free fares a regressive policy that primarily benefits wealthier occasional riders. Better targeted subsidies, they argue, would achieve equity goals more efficiently than blanket free fares citywide.

    518 tokens in, 401 out · 6.6 s · $0.0050 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

20. GPT-6 Astra

    Passed: Graded 4.7 of 5 on average (lowest 4).

    A city should make its buses free because mobility is a gateway to work, education, and healthcare—not a privilege reserved for those who can afford each trip. Eliminating fares delivers immediate relief to low-income households, speeds boarding, and removes costly fare enforcement. Funded through progressive taxation, free buses spread the cost fairly while making public transport an easier choice. A city already pays for streets everyone can use; it should support shared travel that uses those streets more efficiently.
    
    But a free bus that arrives late—or never comes—is no bargain. Cities should spend scarce transit funding on frequent, reliable service before subsidizing every rider, including those who can comfortably pay. Lost fare revenue must come from higher taxes, other public services, or the transit budget itself. Targeted discounts can protect people who need help without sacrificing coverage and capacity. To persuade drivers to switch, buses must compete on convenience and reliability, not merely price; better service may deliver greater social and environmental benefits.

    384 tokens in, 197 out · 7.2 s · $0.0137 · 1 message on Pro · answered by openai/gpt-6-astra via OpenAI · September 27, 2026

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