Toyota develops THUMS crash test simulation software in preparation for automated driving

23 March 2023

Toyota has announced further development of THUMS (Total Human Model for Safety), its software programme for computer simulation and analysis of the injuries resulting from vehicle crash impacts. The latest advances take account of changes in people’s posture when taking advantage of automated driving systems.

The latest Version 7 of THUMS has improved modelling of the human body – men, women and children – with more accurate rendering of the geometry and properties of key body parts, including the pelvis, abdominal organs, spine and ribs. The programme can further predict the impact on human bones, organs and muscles when vehicle occupants are in a reclined position, and reproduce how people will change their position and brace muscles when manoeuvring a vehicle in an emergency, or when safety systems such as a emergency braking and steering control kick in.

They also address the changes in people’s posture as automated driving systems become available. For example, ADAS (advanced driver assistance systems) at SAE Level 3 which see the car automatically carrying out most of the driving tasks, so the driver can sit back and relax. When a person is in a reclined position, the body reacts different with the seat and restraint systems. Even when they are sitting up, the change in posture can lead to significantly different effects in the event of an impact, causing different types of injury.

The new capabilities allow for even more precision in the computerised crash simulations, helping in the development of more effective safety provisions.

Sabine Compigne, Technical Manager in Toyota’s R&D Safety Research operations, explained: “Special attention must be paid to ensuring that the pelvis remains in the seat at the time of a crash. This is crucial to avoid the ‘submarine effect’ where the occupant slides out from under the lap belt, risking abdominal injuries. Good pelvis retention helps to limit compression on the spine and thus prevent spinal injuries.”

The principles of the THUMS programme make it valuable for safety research in other transport fields, such as trains and aviation. Recognising this, Toyota has provided free access to its know-how since 2021, with a view to helping built a future safe mobility society.

THUMS timeline

1997Toyota begins development of THUMS with Toyota Central R&D Labs
2000Version 1 released: detailed modelling of bones added
2005Version 2 released: detailed modelling of faces added
2008Version 3 released: detailed brain modelling added
2010Version 4 released: detailed modelling of internal organs
2022Different physiques added: small female and large male models added
2015Version 5 released: modelling of all body muscles added
2016Child models added to Version 4: child models representing ages 3, 6 and 10 years
2019Version 6 released: muscles added to internal organ modelling
2021Free access to THUMS enabled from January 2021
2023Version 7 released: increased accuracy in geometry and properties of key body parts; modelling to show effect of occupants in reclined position.


Download this release as a PDF below

Toyota develops THUMS crash test simulation software in preparation for automated driving


Images are copyright free for editorial purposes only

Toyota achieves greater test crash simulation with latest THUMS advance in computer modelling of the human body.

Media enquiries

Please click here to see the press contacts at Toyota (GB):

Show Press Contacts

For further information, please contact:

David Crouch

07909 900 085 or by email at

General, fleet and motorsport media enquiries

Please understand that our press team only deal with enquiries from media representatives.

Toyota and Lexus Press Releases

To receive all Toyota and Lexus press information, please select the box below.

To update your profile type in your email address and press return. MailChimp will then send you an email confirming your details and you will then have the opportunity of amending your details.

* indicates required
All Toyota/Lexus News