[2] In 1969, Henderson was part of a team of experts that worked with Pininfarina and Automobil Revue to design a safe racing car known as the Sigma Grand Prix.
"[4] By 1970, he had moved to Australia and became head of the newly formed Traffic Accident Research Unit of the Department of Motor Transport of the NSW government.
He was instrumental in introducing enforced fitment and use of seatbelts in Australia, improvements in child restraints and motorcycle helmets, introduction of helmets for bicycle riders, and steps which helped change the attitudes of the public to drink driving, so that there was a reduction, particularly in NSW, in trauma and death, and which began a continuous reduction which continued for decades in NSW.
Even though there have been changes in the way it is administered, the essentials of the approach to road vehicle safety initiated by Henderson are now incorporated in the Centre for Road Safety of the Roads & Maritime Services of the NSW Government, and which includes an expansion of the testing laboratory of the Engineering Research Section originally at Rosebery, now in Huntingwood (now called Crashlab) which conducts full-scale vehicle crash testing, and testing of helmets, adult and child and baby restraints, and safety work harnesses.
[13] Henderson was appointed an Officer of the Order of Australia in the 2021 Queen's Birthday Honours, recognising his "distinguished service to motor vehicle and motorsport safety, and to the prevention of road trauma".