A manhunt has been launched for a truck driver who killed a couple on their way to a wedding last year seven months after he plowed into their car with his 18-wheeler.

Authorities are searching for Jaspreet Singh Chahal, 24, who is wanted for the deaths of Joseph Kearney, 42, and Kathryn Schurtz, 35.

The pair died in Pennsylvania last year after Chahal's 18-wheeler rear-ended their SUV. They were driving to their wedding at the time.

Chahal stayed at the scene after the crash and sat on the side of the road but refused to answer questions.

He was not charged at the time but now, seven months later and as the result of labored investigations, he has been charged with vehicular homicide. Detectives however cannot find the man, who is a California native.

They say he was talking on the phone to his sister at the time of the crash and failed to break.

No photographs have emerged of Chahal and police are yet to explain why it has taken so long for an arrest warrant to be issued.

Joseph Kearney, 42, and Kathryn Schurtz, 35, were crushed to death by the 18-wheeler last November

Firefighters extinguish the blaze that engulfed the couple's SUV and two trucks on the Interstate 78 on November 14 2018

Joseph Kearney, 42, and Kathryn Schurtz, 35, were killed in the crash

'We have to find him,' Berks County District Attorney John Adams said.

'That is our main goal at this point.'

Chahal may not even have hit the brakes before impact.

'I've seen many horrific facts from accidents,' Adams said.

'In this case, we certainly believe he never braked before impacting the vehicles ahead of him, which makes … the facts of this case extremely egregious.'

The couple, from New Jersey, were driving to their wedding in Pittsburgh, Pennsylvania, when the accident happened.

State Trooper Travis Rutt, the first officer to arrive on the scene, found the couple's car and two of the trucks involved already ablaze.

Joseph Kearney, 42 (left) and Kathryn Schurtz, 35 (right), both from New Jersey, were killed when Jaspreet Singh Chahal's 18-wheeler truck plowed into their stopped SUV

The crash had pushed the couple's car under the rear of another tractor-trailer and caused what Rutt called a 'chain reaction of impacts' involving a total of five trucks.

Rutt had been posted further back along the road to warn drivers of the roadworks and tailbacks ahead.

The right lane was closed with traffic cones and signs.

Two 'Road Work Ahead' signs were placed 2 miles before the works, and an electronic message board about 1.5 miles before the lane restriction, but traffic was backed up past that after an earlier accident.

Roughly and hour after the crash the county 911 centre told the Hamburg station that a woman who identified herself as Chahal's sister had called them out of concern for her brother.

She said she had been speaking to him by phone when she heard a commotion and his electronic logbook disconnected.

The aftermath of the November 14 2018 crash on the Interstate 78 near Windsor, California, which killed a couple on their way to their wedding

Kearney and Schurtz were pronounced dead at the scene from crushing injuries.

Schurtz worked as Head of Platform Partnerships for Oracle Data Cloud in New York City, according to NBC 4.

Her obituary said her loved ones will cherish memories of the George Washington University liberal arts degree graduate, who earned an MBA from the prestigious Notre Dame.

'She will be remembered for her voracious appetite for reading, love of cooking, and trailblazing new adventures with Joseph,' it read.

She survived by her parents, Joseph and Karen; sister, Kimberly, her sister and brother-in-law Joanne and Kevin Schwoer; and her three-month-old nephew Landon Schwoer.