They will learn. The summer truce is over and one of the world's most vicious gang wars is set to break out, with renewed ferocity, across the streets of Britain. From Dover to Dundee the hardened gang members are honing their weapons and preparing for battle. Unlike the pampered denizens of Los Angeles and the Chicago South Side, Britons will not be sheltered from the fighting if they stay clear of the ghettoes; this turf war is taking place on every highway and byway. And it's lethal: every year, people get killed, more are wounded, and thousands of others are left quivering in their seats as witnesses to the mindless carnage.
The war is a universal one and the gangs incorporate virtually every citizen of the United Kingdom, whether they want to belong or not. For all of us have, at one time, been pedestrians, cyclists, bikers or motorists. John Prescott may talk about making our roads safer, happier places but, as Britain's population is brought up to normal again by the return from the Costas, the ugly truth will dawn. It's war out there.
Our street violence is a serious business: 973 pedestrians were killed last year, as were 2,826 other road-users, and even the most seemingly innocuous battles can be deadly: six cyclists and pedestrians died last year after crashing into each other.
Last year, a grandmother chased a 13-year-old cyclist and knocked him down with her car; a fireman repeatedly bashed the head of a cyclist against a wall; a cyclist threw his bike at the windscreen of a car. Martin Shaw was attacked by a bus-driver after shouting at him for cutting him up as he cycled down a London street.
No matter how much cyclists believe they are doing the rest of the world a favour, the rest of the traffic - whether motorised or on foot - does not agree.
"They're a menace," said one man, walking his dog gingerly along the pavement. "They take no notice of red lights or pedestrians, whether it's a pram or a pushchair. What's worse, they knock you over as they cycle past, and then look back with a gesture of contempt. In the great battle for the pecking order, they think they have moral superiority. They feel they're victims of trucks, but to us pedestrians they are just as much bullies as any trucks."
London cabbies are scarcely less irate, but the object of their ire are other road users of all descriptions. Raymond Games, a 47-year-old London taxi-driver, said: "What amazes me is so many pedestrians act like they're blind. I've seen a woman walk straight into the path of a cab in front of me - bam!" (He thumps his fist into his hand.) "I used to keep wary all the time, but now, if get another idiot stepping off the kerb without looking, I don't know that I'll slow down, even if I can". His mate, a spindly chap who didn't want to give his name, blames motorbikes. "You're sitting at the lights and five of those couriers slip in and stand in front of you. You gotta try not to lose it in this job, but I've half a mind to step on it and flatten 'em all." He laughs wheezily. "Maybe I could get stickers, like stick one inside my cab for every one I get."
"If cyclists want to cut me up that's their problem," said Wayne McKinsey, who was reloading his red Peugeot 306 GTI at the Texaco station on the Talgarth Roundabout. "I'm not trying to hit them, but I'm sick of getting out of their way when they do something stupid. In a car, I can just put my foot down in this and get out of trouble."
Others are more protective of the vulnerable creatures on two wheels.
"This guy was driving like an idiot in this Golf on the A3," said Paul Ross, a 31-year-old researcher who had stopped for petrol. "He was weaving in and out of all the busy lanes, and he almost killed a guy on a motorbike - he had to swerve to get out of his way." So did Paul take him on?
"No, I called the local police station on my mobile phone and told them what was going on. They said they'd go round to his house with a warning."
On London's Embankment last week, several hundred cyclists gathered at the height of the evening rush hour to test the tempers of other road users in the monthly Critical Mass run. This event is replicated in cities across the world; it involves a gang of cyclists stretching across one entire side of a road and pedalling at their own pace to a destination chosen at random by the lead cyclists. "Last time we ended up having a party in a disused petrol station on the City Road," says one of the organisers, "with music from a pedal-powered hi-fi system."
Patrick Field, head of the London Cycling School, brings a Sufic philosophy to the battlefield: "I don't get angry at motorists; I feel sorry for them," he says. This approach makes life much easier during confrontations: "I tell them there's no need for bad language, and ask if they've had a bad day."
In the end, he says, "it's not cyclists that hold them up. It's other cars." So they're just jealous.
The cyclists on Critical Mass believe that hogging the road is a neat turnaround from the normal situation when they are squeezed out, often dangerously, by motor vehicles.
Even the normally serene spokeswoman from the Department of Transport was moved to fury when I brought up the question of which gang, statistically, was most dangerous to belong to.
"I'll tell you what's dangerous," she rapped. "It's bloody dangerous to be a pedestrian, because of all the cyclists on the bloody pavement! That's what's dangerous. You tell them it's illegal. I got rear-ended walking down Whitehall last week."
One cyclist claimed to have been flattened more than once by motorists - and in one case, a black cab - pulling out of side turnings without looking.
"You're completely vulnerable," he said. "Drivers tear past you without leaving an inch to spare. They just never look for you."
She also had an explanation for the fury so often displayed by cyclists in any confrontation with drivers - one which the good citizens of Weston- super-Mare might do well to heed.