An emergency treatment using a balloon device to control catastrophic bleeding in accident victims is being trialled as part of a new £1.1m study.
The University of Aberdeen trial - over four years - compares the survival of those who receive the treatment against those who do not.
Reboa (resuscitative endovascular balloon occlusion of the aorta) works by inserting a balloon device into the body's main artery.
London Air Ambulance has used it.
The trial will examine if the technique can prevent deaths and disability from road collisions and falls from height.
The study is being supported by a £1.1m grant from the National Institute of Health Research.
The trial will take place across 10 major trauma centres in England.
The research team estimates about 120 patients may be treated using Reboa during the course of the study.
It was first used in the UK by the Royal London Hospital.
Pedestrians or cyclists involved in serious crashes often have internal bleeding due to injury to blood vessels deep inside the body, but these cannot be compressed from the outside.
Some people will die at the scene or before they can be transferred safely to hospital.
The technique allows doctors to control bleeding from within.
Jan Jansen, a consultant in general surgery and intensive care medicine at the University of Aberdeen and the chief investigator of the study, said: "Reboa is quite a simple concept which many in the medical profession believe will be a tool that helps save more lives.
"This trial will provide evidence that either supports or refutes that conception.
"The technology is not without its complications. Cutting off blood from half the body can only be done for so long and you have to deal with the consequences of that but with injuries this severe it can be a trade-off worth making.
"We want to find out if it is worth taking an extra few minutes to do this procedure and arrive in the theatre in a more controlled state."
He added: "It's important to stress that this procedure is only used in extreme cases where there is a real chance of the patient dying in the emergency department.
"All teams involved will be given bespoke training and, as well as assessing the success of Reboa, we will be evaluating how practical it is to incorporate into the procedures of each individual trauma team.
"Some early adopter teams have already started using this but this trial will provide some thorough research that shows just how effective it is at saving lives."