Investigations are underway into 46 fatal collisions in South Yorkshire, with 24 drivers, passengers and pedestrians killed and 325 seriously injured on the county's roads so far this year.
With each collision unique and with their own particular set of circumstances, investigations can take months, if not years to complete.
Rewind 20 years and police officers would have turned up at a crash scene with a measuring tape and a chalk stick as they tried to piece together what had happened.
Today they have all the tools at their fingertips that police officers use to solve all other crimes - including the latest in forensics technology, CCTV cameras to analyse and mobile phone records to monitor.
Sergeant Steve Askham, who has investigated hundreds of fatal and serious collisions over the years, said: "There is no such thing as an accident - everything happens for a reason and it is our job to find out why.
"There is very rarely just one cause, It is common that a number of factors come together."
Having knocked at doors in the dead of the night to inform relatives that loved ones have died, Sgt Askham said he is committed to providing answers to help grieving families come to terms with their loss.
Some investigations lead to criminal court cases with people accused of causing death by dangerous driving, while others end up before a coroner when no criminal blame can be found.
But in all cases families of crash victims always want answers.
"It is very very demanding to have to break the news that somebody has died and each family is different in the way they accept that - grief is very powerful and everyone reacts differently to it," said Sgt Askham.
"Some will be overcome with emotion and others might strike out at you because you are delivering something that they do not want.
"Our role after that is to find out what happened and why. The relatives left behind have a right to know that."
From police officers arriving at crash scenes and dealing with the initial aftermath - which can include battling to revive casualties to diverting traffic away - investigations into the circumstances surrounding the collisions also start immediately.
Treated as crime scenes, photographs of crash sites are taken, tyre marks are measured, the weather and road conditions are noted and vehicles are examined.
Debris left at the scene is painstakingly examined, with officers looking for anything which could shed some light on what might have caused a crash.
But once the mangled cars are towed away, crash barriers are repaired and roads are re-opened, the next phase of collision investigation begins.
"We accept nothing, believe nothing, challenge everything and seek corroboration," said Sgt Askham.
Interviewing witnesses is still vital, but unlike years ago officers now have technology to help piece the jigsaw together.
CCTV footage can be analysed to suggest the way a motorist was driving before a crash and mobile phone records can be checked to establish whether a driver was making a call or texting at the time.
Vehicles are meticulously examined for defects, road surfaces are tested, drainage systems are looked at and alcohol and drug tests are carried out, with investigators looking for the clues they need to establish what exactly happened.
Sgt Askham said motorists need to think twice about their actions or face the consequences - either with their own life or a victim's.
"I believe that people believe modern cars can save you - they think they are safe because of all the features such as air bags and anti-skid technology but they are not," he said.
"What has not changed is the mark one human being behind the wheel. There is only so much we can be protected from.
"I have seen the consequences of people taking a risk, or a minor lapse of attention and those who knowingly get behind the wheel while unfit to do so. They may not have set out intending to kill somebody but because of how thorough our collision investigation is prison is a significant prospect if you are involved in the death of someone.
"Being responsible and careful and doing your utmost to comply with the rules and regulations of the roads will go a long way to preventing more road deaths."
*Year to date figures as at 19/10/16
- Marie Cross, aged 36, died after in a hit-and-run in Thurnscoe last month.
She was crossing Barrowfield Road, with her partner when she was struck by a car which failed to stop at the scene.
A 36-year-old man and a 26-year-old woman were arrested on suspicion of causing death by dangerous driving and have been released on bail pending further inquiries.
- Darren Cunningham, aged 29, died after he was struck by a a BMW which had been involved in a crash with a Vauxhall Corsa in Balby Carr Bank, Doncaster, on Saturday August 6.
A 44-year-old man driving the BMW was arrested on suspicion of driving over the prescribed limit.
- Cyclist Jonathan Craig Highfield, aged 38, from Worrall, Sheffield, died in a collision with a car at the junction of Loxley Road and Wisewood Lane, Hillsborough, on Wednesday, July 20.
The married IT manager was involved in a collision with a black Nissan Micra, driven by a 67-year-old man, who was arrested on suspicion of causing death by dangerous driving before being released without charge.
- Brothers Raymond and Arthur Sharkey, aged 77 and 79, were walking arm-in-arm when they were struck by a blue Audi A4 carrying out a manoeuvre on Glenorchy Road, Nether Edge, Sheffield, on June 2.
They both died weeks after the collision.
A probe is underway.