It feels wrong to begin any upbeat piece about the coronavirus crisis without first acknowledging the terrible tragedy of it. The lives cut short. The family and friends left grieving. The healthcare professionals working long hours in trying conditions without the support they deserve. Those who have lost their jobs or been left struggling financially.

But in any loss, there is also opportunity. An opportunity not to try to return to normal as quickly as possible, but to invent a new normal …

London is a wonderful city. I don’t deny my bias, but it’s not blind loyalty. I’ve visited scores of cities around the world, and fallen in love with a number of them. Boston, Cape Town, Melbourne, San Francisco, Shanghai, Vancouver …

While London will always be first among them, and I fully intend to live out the rest of my life here, I’m not blind to its flaws. Some of them are endemic and hard to solve – like the lack of affordable housing. But there are others whose solution is simply a matter of political will.

Our transport problem is one of these. Sure there are physical capacity limits to the tube – though driverless trains and DLR-style signalling systems can allow trains to travel much closer together, giving a much more frequent service.

But by far the biggest opportunity is to make more efficient use of the huge amount of space and priority given over to motorised transport.

I’m not suggesting we can completely lose motorised transport in central London. We need buses. We need lorries to restock our shops. Service engineers need vans to transport their tools and their parts. For some people with disabilities, cars may be their only practical form of transport. And so on.

But we can radically change our transport mixture.

We have demonstrated time and time again that if you make cycling to work safe and pleasant, lots of people choose to do it.

Take the stretch of Embankment between Tower Hill and Parliament Square. You once had to be a pretty hard-core cyclist to mix it with the traffic along there. But when we took half of the space away from cars and gave it to cyclists in the form of fully-segregated cycle paths, suddenly more than 10,000 cyclists a day use that stretch.

On a larger scale, Amsterdam shows what’s possible. People always seem to dismiss it as a different world, but the city was once very much like London. Motorised traffic had priority, and relatively few people cycled. The same arguments were made about segregated cycle paths: it’s a crowded city, there’s no room for them, you’ll create traffic chaos if you take space away from cars.

But Amsterdam did it anyway, and the threatened Armageddon didn’t happen … because people got out of those cars and onto bicycles.

The same is true of pedestrianisation. Opponents claim it will devastate shops and restaurants; but when it happens, the opposite is shown to be the case. Make it pleasant to walk along a street and more people come, not fewer.

The lockdown is an unprecedented opportunity for London to transform itself, for three reasons.

One, people have been given a glimpse of what’s possible. They’ve experienced London with clean air and clear skies. They’ve enjoyed cycling on almost car-free roads. They’ve experienced what it is like when pedestrians, not cars, get the use of streets.

Two, lockdown is the perfect time for major construction work, when few will be inconvenienced, and when jobs are sorely needed. And the government has already demonstrated that the way to respond to a crisis on this scale is with spending, not austerity.

Three, people’s eyes have been opened to new possibilities. Who could have imagined a Tory government creating the biggest welfare system the UK has ever seen? Companies which once viewed home-working with suspicion have embraced it, and seen it work. When supermarkets struggled to keep up with demand for home deliveries, people discovered small independent greengrocers and dairies. People have been doing more cooking. Ironically, many have been getting more exercise. People are open to a new normal.

This is, literally, a once-in-a-lifetime opportunity. Milan is already planning to take full advantage of it. I really hope we do the same.