It seems like such a good idea. Nearly all road deaths are caused by human error so why not eliminate the human factor by making vehicles driverless? The technology companies and auto manufacturers are so convinced that this is the future that they are investing billions of dollars in the concept. And they are making a lot of noise about it.

Hardly a day goes by without the announcement of a new development with the promise that driverless taxis, platoons of trucks or even pizza deliveries will be coming soon, or at least by 2021, 2023 or whenever. But just recently, cracks have been appearing on the road to this ever-distant nirvana. When Elaine Herzberg was run over and killed by an Uber-operated car in autonomous mode in Tempe, Arizona, in March, the company immediately ceased its driverless taxi testing across the US. A few days later, a Tesla car in autopilot mode crashed into a concrete barrier on Highway 101 in Mountain View, California, killing its occupant, Apple software engineer Wei Huang. That came on top of a similar death involving a Tesla driver using driverless mode in Florida last year. These tragic accidents have had the side effect of prompting a much-needed debate on the adoption of this technology. That is the last thing these companies want, as witnessed by Uber reaching a settlement with the Herzberg family in March, which ended a potential legal battle.

These companies have presented this technology as a future that will surely come to pass and they are selling it to the public on the basis of safety, reduced congestion and greater convenience. Yet the very concept may in fact be fatally flawed because “bad people” will potentially be able to stop the car simply by standing in front of it, or because the technology will never become as good as a human driver. There are countless other potential obstacles to the widespread adoption of these vehicles. But even if they can be overcome, the promised benefits may be illusory.

As these accidents have shown, programming a car to cope with all the eventualities of driving – fog, snow, pedestrians, cyclists, potholes, lack of road markings, unexpected roadworks and countless more – is a tough ask. Humans, with their excellent eyes and big brains, are able to anticipate the actions of other road users to avoid accidents. Nearly all these driverless vehicles have human operators to intervene if the car makes a mistake – and therefore the claim that they have run for millions of kilometres without incident is misleading. Indeed, in one week in March 2017, operators of Uber’s driverless taxis in Pittsburgh intervened, on average, every 1.2km. Moreover, as more functions are taken over by the vehicles, the risk that drivers will fail to assume control when they need to becomes ever greater. As for congestion, having empty cars (those being sent back home or to a carpark, for example) on the already crowded road will add to traffic jams, not reduce them.

There is no business model – given the expected high cost of the vehicles – nor any consumer clamour, for that matter, for the introduction of this technology. Most people in surveys say that they still enjoy driving. The problems posed by our transport system have countless low-tech solutions, which many cities across the world are introducing, ranging from congestion charging and pedestrianisation to new light-rail systems and better traffic-light control. The problem in every city is too many cars chasing too little space. Removing cars, rather than drivers, is the solution.

First up, the bad news: the use of public transport in many US cities, alongside London and some other European hubs, has been declining. These trends are the product of different circumstances, including the underperformance of slow-moving agencies that don’t provide the amount of service that customers need and governments that continue to lavish huge hidden subsidies on roads. Fare levels, changing commute patterns and emerging competition from app-enabled ride-hailing services can also discourage public-transport growth.

But we shouldn’t sound the death knell just yet. As long as city-living continues to exert its strong pull (and people want to live in places with economic and social interaction) the realities of time and space will make public transport essential. There’s lots to be done, sure – namely improving frequency, speed and connectivity – but some cities are showing the way.

Indeed, it’s the hubs whose public-transport agencies know how to adapt, redesigning their offerings and expanding their usefulness, that are attracting more riders. Ridership has grown in Sydney, Melbourne and Adelaide, where government authorities let private bus companies vie against each other to win government subsidies, with incentives for achieving goals such as punctuality – and fines for failing. Seoul, meanwhile, in addition to boasting one of the world’s largest metros, has achieved huge gains in bus ridership due to frequency and reliability along a network of dedicated lanes. Investments in additional service, connectivity and speed in Vancouver, San Francisco, Houston and Seattle have attracted more ridership.

That cities are composed of people living together is not just a physical fact but also a social asset, not merely in terms of public transport but in terms of public life. An investment in public transport is a decision to build a more inclusive city because physical mobility means socioeconomic mobility: access to a wider range of jobs and social participation. Good public transport is the creation of more “public space” – the civic commons on wheels.

The city of Seattle in the US’s Pacific Northwest is surrounded by three bodies of water, the largest being Elliott Bay, which is part of the much larger Puget Sound Basin. It’s a stunning landscape that feels a million miles away from town. If, like me, you live on one of its many islands and peninsulas and work in Seattle, you also happen to have one of the world’s greatest commutes.

I begin my day by driving my electric car to a ferry terminal on Bainbridge Island where I park, stop for an espresso and walk to the Washington State ferry. Believe it or not, WSF operates the largest ferry fleet in the US and second-largest in the world; some 6.5 million people travelled my route last year.

Once aboard I walk to one of two unmarked “quiet rooms” on the upper deck. Although there are no signs dictating recommended behaviour, it becomes immediately obvious that talking is verboten. More importantly, no one is screaming into their mobile phone. In the collective silence people read, listen to podcasts or music through headphones, sleep, eat, work or stare out at the ships and orca whales passing by. Very occasionally, Mount Rainier breaks through the clouds, accented by the sunrise. It can be remarkable. I usually spend the 35-minute trip drawing ideas for architecture projects.

Once in Seattle I walk off the ferry, put on a helmet and hop on a bike – provided by one of the city’s three bicycle-share systems – to Olson Kundig’s Pioneer Square office. Seattle is the first US city to try “dockless” bike shares, a system that has transformed commuter transport in China in recent years.

For my return commute, the sun is usually setting over the Olympic Mountain Range, beer and wine are sold on the boat and there are final emails that need answering. It always surprises me that people assume the ferry must make for an unusual hardship for those of us living in suburban or rural communities outside Seattle. I restrain from telling them it’s about as hard as going on holiday twice a day.