For three months after the murder, few outside his small circle knew of Ahmaud Arbery. Even now, when runners around the world are honouring him and mainstream news organisations are covering the trial of his alleged killers, he will never achieve the grim fame of George Floyd. His fate deserves to be remembered, however, and not only for the usual reasons of showing posthumous respect.

The wider lessons of Arbery’s death do not only instruct us on racial hatred but on a neglected topic that will have to be addressed if the hopes of moving Western societies away from obesity, pollution and chronic illness are ever to be met. Public health is a law and order issue. People need to feel protected on safe streets if they are to take up walking, running or cycling.

Ahmaud Arbery had the right to feel safe when he put on his trainers. He was 25 years old and black. A former high school football player from Georgia in the American south, he kept fit by running regularly. On 23 February, he went for a run in the Satilla Shores neighbourhood near the town of Brunswick. Three white men decided that a black man running must be a criminal. They targeted, tormented and hunted him, the prosecutor said as the case began earlier in the summer.

Gregory McMichael, 64, and his son Travis McMichael suspected that Arbery was the perpetrator of a series of break-ins. Instead of calling the police, they armed themselves, got into a pickup truck and set off after him.

He tried to swerve away from the truck when he saw it blocking his way, as runners do whenever there’s an obstacle in their path. He turned and ran towards a third man, Roddie Bryan, who was filming the chase from his own pickup. Bryan allegedly smashed the side of his truck into him. The trapped Arbery turned to fight off his pursuers. The younger McMichael came at him with a gun, they struggled out of sight of Bryan’s phone camera, and then shots were heard.

Georgia prosecutors initially said there was no case to answer. And the defence is arguing the same. It was only when Bryan’s video appeared on the web that the police showed interest.

Friends put out the hashtag #IRunWithMaud encouraging people to go out in his memory, and his death has become a cause célèbre in the running world. The case was still being heard at the time of going to press, but you can already guess the answer to one question it raises: if you were a black runner in Georgia would you run through this neighbourhood?

I could leave the story there. Writing about the US from Britain brings with it the danger of self-satisfaction. We don’t have a gun culture and extraordinary levels of violence. We do not pass strangers and wonder if they will shoot us dead.

There are no grounds for British complacency. Women runners routinely experience harassment. I remember seeing a guy go for a young woman who had bent over to tie up her shoes. He grabbed her backside and scurried away. It was so unexpected and over so quickly, I just stared.

A year on, I am still ashamed of myself for not realising what was happening and intervening, and I still wonder if she goes out running by herself now. Many say women should never run alone, but that sounds disgracefully cowardly. When Avon and Somerset Police said in 2019 that women should join clubs and go out in groups, women runners asked why the onus was on the innocent to take precautions rather than on the guilty to stop harassing them.

You can have all the pedestrianised streets you want, but people won’t take to them until they’re safe

Beyond running lie the fears of wider society. If air pollution that claims so many lives, and the obesity that afflicts a third of the population, are ever to be tackled, more people will have to want to walk, run and cycle, not necessarily for any noble notion of the common good but for their own good.

The conventional list of demands ought to be familiar by now. The government needs to allow more space for cyclists and pedestrians, and to stop insisting that zebra-crossing must meet hugely expensive conditions before they can be painted on roads. I could go on but the vaguely leftish green agenda is well enough known.

One undiscussed area remains. You can have all the cycle lanes and pedestrianised streets you want, but if people feel they will be robbed or sexually assaulted, they won’t use them. Law and order used to be a concern of the right and the Blairite centre-left, until the Cameron government pretty much gave up on it. But if you want a healthier and cleaner country you have to think about it again. People won’t take to the streets until there are safe streets.