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  • Maintains the vehicle’s roll radius characteristic allowing the vehicle body to roll smoothly.

    • Prevents vehicle corners and sides from buckling and landing on the weak roof panel.

  • Distributes the roof loads across the HALO structure for even roof structure ground loading.

    • Prevents jarring loads on the occupants and minimizes point loading on the vehicle.​

  • Minimizes roof intrusion and intrusion speed which can cause injury to occupants.

    •  Prevents the structure from collapsing into the occupant compartment too far or too fast.


The HALO is a High Attenuation Load Offset device and when is attached to a production vehicle roof, reduces the amount of crush and the speed of that same crush when the vehicle experiences a rollover crash to prevent catastrophic and fatal injuries to the occupants. 
The HALO is designed to maximize the vehicle’s own geometry to minimize and evenly distribute the impact forces of a rollover event over the entire vehicle body structure preventing point loading in any one place.


The HALO was developed as the first embodiment of more than 20 years of intensive synergistic Australian and United States (US) scientific research by Mr. Donald Friedman from the US Center for Injury Research and Dr. Raphael Grzebieta, a professor previously at Monash University (AUS) and now at the University of New South Wales (AUS). Their focus was defining the most effective and economical means of mitigating deaths and injuries in rollover crashes.

Understanding “Real World” rollover crashes during the development of the HALO was critical to SEI in pinpointing the key areas of the vehicle’s roof structure that required improved geometry and reinforcement without interfering with the occupant protection systems in the vehicle. The research included over 500 “Real World” crash investigations and over 300 rollover crash tests performed in the innovative dynamic test rig called the Jordan Rollover System (JRS). Over 100 conference and journal papers, presentations and reports on how to mitigate rollover injuries were published. This research work has been peer reviewed by other leading researchers, government and industry.

Rollovers producing serious to fatal injuries are characterized by substantially greater roof intrusion on one side than the other. Our research identified the geometry of the roof and its strength as the primary and equally significant factors in reducing the roof intrusion and intrusion rate, and head, neck, and chest injuries to restrained occupants.  [In essence, modifying the roof structure to maintain the vehicle’s roll radius allows it to roll like a cylinder instead of like a brick, resulting in constant roof to ground loading.]  Such modifications could be integrated into production vehicle designs after a period of real world functional proof from HALO equipped vehicles.

The HALO is a scientifically innovative and comprehensive solution for mid-size SUVs and 4WDs vehicles. The HALO can also be applied to heavier vehicles used in agriculture and excavation. It was developed, tested, and sold in North America, South America, Australia, and the Middle East region with negotiations underway for sales in other countries and regions such as Africa and Russia. The underpinning innovative concepts on which the HALO was developed are outlined in the US Patent #7717492 by Friedman and Grzebieta. Four papers presented in Australia, US, Brazil and Singapore further detail the innovation and testing performed to develop the HALO™ into a commercial ready product.

Part of the basis on which the HALO performance specifications were established was an “in-depth” crash reconstruction analyses of typical on-road tripped rollovers investigated in Australia and the US. It was found that in approximately 90% of Australian and United States rollover crashes, the rollover was a lateral rollover resulting in two rolls or less.  In addition, more than 500 rollover crashes were investigated demonstrating that significant injury or fatality occurs most often on the far side of the vehicle, where there was a forward pitch angle of greater than 5 degrees and more than 100 mm of roof crush over the occupant and typically forward of the B-pillar.

When considering these factors, any roof strengthening system must be effective in preventing the front A-pillars from crushing as well as encompass a means of distributing the roof loads incurred in a rollover uniformly across the structure of the underlying vehicle. The HALO was developed based on our understanding of how vehicles roll, the load paths in the roof structure during the crash event, and how roofs crush during a rollover.

More recently the National Highway Traffic Safety Administration (NHTSA) announced its upgrade of Motor Vehicle Safety Standard 216 for roof crush resistance and in doing so ended the 30 year-old battle over roof crush as an injury producing phenomenon. Safety Engineering International founders were an integral source in the upgrade of the Motor Vehicle Safety Standard 216, submitting thousands of pages of reports, data, testing, analysis and research to the NHTSA docket and then quoted in the issuance of the final rule. We have integrated this knowledge into designing a roof retrofit device to minimize roof crush on production vehicles in rollovers crashes.


Car Outline


Safety Engineering International owns 
United States Patent No. US 7,717,492, named HALO™.

HALO™, a vehicle Rollover Occupant Protection System is available worldwide.

International Patents include: 
South Africa Patent No. 2011/02026  
Australia Patent No. PCT/US2009/054293
Singapore  Patent No. WO/2010/022141 
Canada Patent No. CA 2735042

Brazil Patent No. PI 0912940-5
India Patent No. 326084
Korea Patent No.10-1586519

Mexico Copyright Registration No. 03-2016-120912494800-001

SEI and HALO logos are marks of 
Safety Engineering International © 2021.  All rights reserved.

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