Wheelchair man gets long truck ride

Not as simple as it sounds. This was actually a pretty scary thing that scared a number of observers. Imagine if you will, a truck speeding down a highway, with a man in a wheelchair being pushed by the truck at high speed, with the man hanging on for dear life.
They moved along like this for some time, with the man in the wheelchair whizzing by at a high speed, but thankfully, after some time the truck pulled over and bystanders came and rescued the man. What probably saved the man in all this? The good quality of the wheelchair and the seat belt that kept him safely in the wheelchair. This actually happened:

A wheelchair user has been taken for a high-speed ride along a US highway after his handlebars became tangled up in the front grille of a lorry.
The driver was completely unaware that he had a new passenger, kept in his wheelchair by a seatbelt