Anton Maizen ploughed his 40-tonne lorry into a queue of traffic on the M25 near Aveley in Essex
killing a 79-year-old man and injuring two others
admitted one count of causing death by dangerous driving and two counts of causing serious injury by dangerous driving
He was jailed for four and a half years at Basildon crown court
came after Maizen had been at work for nearly 23 hours – driving for 15 of those hours without a break
Maizen's 840-mile journey had begun the previous day in Germany
with the driver entering the UK via Folkestone
before continuing on his way to Lincolnshire
He was returning to the Channel Tunnel when the crash took place
Maizen was unable to explain why he struck the rear of the queue at his maximum speed of 56mph
which contained a mother and her young son
propelling the vehicle into another lane and into the path of a second lorry – though both escaped serious injury
Maizen's tachograph charts were found hidden behind the driver's seat and a data chart in his sock was later found disclosing his route and timings
Inspector Keith Whiting of Essex police said: "We believe drivers and owners of foreign and British commercial lorries will take note from this tragic incident that those who disregard the law and the safety of vulnerable people in smaller vehicles around them will be brought to justice
face a prison sentence and a lengthy disqualification
"We also believe that people who were disrupted for several hours as a result of this crash will appreciate that the complex and meticulous investigation undertaken by Essex police's serious collision investigation unit was justified and has successfully brought a driver to justice for causing one death and serious injury of two other road users."
The German motorist was disqualified from driving for five years and ordered to take an extended driving test in order to regain his licence.