Stevenage crash: What are car cruises?
Seventeen people have been hurt in a crash at a car cruise event in Stevenage - but these gatherings happen all over the country, often attracting hundreds of cars and spectators.
So what are car cruises and what do people think of them?
What happens?
Car cruises give owners the chance to show off their modified cars to fans at a gathering on a trading estate or a car park out of town.
The heady mix of revving engines, powerful sound systems and gleaming chrome attract hundreds of "petrolheads".
"Contrary to what some may believe, it's not a bunch of hooligans in a car park doing their best to upset everyone around them," said car enthusiast Tom Adams.
Why do people do it?
For the love of four wheels and the tang of burning rubber.
"It's a lot of great cars together in one space with great owners attached to them," said Mr Adams.
"You get a great social event, surrounded by the things you love."
Not everyone is keen. Any mass gathering of cars is going to be noisy and smelly, which isn't great if you live nearby.
How does that differ from an illegal car cruise?
Organised car cruises are static, have the backing of police, are regulated by council officers and often raise money for charity.
But local authorities have little control over spontaneous meet-ups which quickly gain traction on social media.
They spill out on to public roads, create a nuisance and put the general public at risk.
The lure of a long, straight seafront attracted speeding and tyre burn-outs at a spate of illegal gatherings in Southend, Essex.
'We're not boy racers'
Car enthusiasts like Mr Adams want to distance themselves from image of boy racers, who "give car cruises a bad name" by speeding and generally causing a disturbance.
Organiser of the Stevenage event Rix Sidhu said: "We've created a community where people were coming down with young children, families coming down just for something to do on a Thursday to look at these vehicles.
"We don't condone street racing, we don't condone any type of racing."
Participants are warned anti-social behaviour will not be tolerated, with the registration numbers of offenders handed to police, he said.
"I know the people who organise these events, they communicate with police and shun people who misbehave, but they cannot control everyone," said Mr Adams.
"I think with publicity on social media they have become too popular."
Has anyone been hurt at an unlicensed event?
In July 2015, 17 people were injured after a Ford Fiesta ploughed into a group of bystanders at a car cruise event in Plymouth - which resulted in a £500 fine for the driver.
A 19-year-old woman died and four others suffered life-changing injuries at an unofficial "car cruise" at Trafford Park, Manchester, in May 2018.
Scott Watkins, 25, was jailed in October for nine years and nine months after he caused the death of Sophie Smith by dangerous driving as he lost control of a high-performance vehicle and ploughed into a group of onlookers.
His BMW 3 Series, a friend's courtesy car, was one of more than 60 high-performance and modified vehicles said to have taken part at the unregulated event.
What do the authorities say?
Police and councils do have extra powers to deal with dangerous driving and anti-social behaviour if car cruises regularly cause trouble.
A five-year High Court injunction in Southend runs until 2023 and car cruises are also forbidden in the Black Country.
In Wolverhampton, more than 35 people have been convicted since 2014 of offences relating to illegal car cruises and been sentenced to prison or fined up to £2,000.
Authorities can also seize and crush vehicles.