Euro NCAP: Trailer rear guards fail crash tests, cost 400 lives yearly
Crash tests show current European trailer guards can fail in rear underruns, and Euro NCAP demands legislators adopt US-style safety rules.
- 400 per year
- 56 km/h (35 mph)
- 70%
- >15 years
What Happened
Euro NCAP, together with Germany's ADAC, Sweden's Trafikverket and the US Insurance Institute for Highway Safety (IIHS), concluded that inadequate rear impact guards on trucks and trailers cause hundreds of road deaths each year. The investigation, initiated and supported by National Highways in the UK and informed by analysis of collision data on the strategic road network, found that trailer rear underrun impacts – where a car slides beneath the back of a heavy goods vehicle – potentially cause about 400 fatalities across the EU and UK annually. The findings come from real-world track tests and crash testing at international research facilities.
The research exposed a double failure: sensors of some older Advanced Driver Assistance Systems (ADAS) fail to see trailers, and physical safety guards on trucks and trailers fail to stop cars sliding underneath in some crashes. All tested passenger cars' ADAS systems featured both camera and radar sensors. When driven toward the standard Global Vehicle Target (GVT) used in all manufacturer tests, the vehicles detected the threat all the time, but against real HGV rear-ends – including curtainside and skeletal trailers and impact protection vehicles used in roadworks – the detection rate fell in several cases.
The testing highlighted a divide between the latest ADAS generation and previous ones. With the average age of cars on the road rising, it will take more than 15 years before most cars can avoid stationary trailers, so improved crash protection is needed now. When driver and systems fail, a trailer's Rear Underrun Protection System (RUPS) is meant to stop the car from sliding beneath it. For crash tests, the car's ADAS were deactivated, and a popular five-star-rated Euro NCAP vehicle was used.
IIHS TOUGHGUARD voluntary standard introduced in the US market
Europe's mandatory rear underrun standard UN ECE R58.03 enforced
- In a 30% offset crash at HORIBA MIRA, the guard offered little resistance; the trailer bed sliced through the passenger
- In a 75% frontal-rear impact by ADAC, the rear underrun bar failed and the occupant compartment was destroyed, leaving n
- In the same 30% offset crash, the guard allowed the car's safety structure to deform and protect occupants as designed.
A proven solution already exists in North America. Since the IIHS TOUGHGUARD standard was introduced in 2017, an estimated 70 per cent of the latest US trailers are fitted with TOUGHGUARD-rated devices. In the EU and UK, meeting this standard would require adding reinforcement to trailers. Euro NCAP says the current R58.03 regulation is not fit for purpose and calls on EU and UK legislators to mirror the US voluntary standard. It urges trailer manufacturers to offer voluntary upgrades and retrofits, and strongly encourages fleet operators to request retrofit solutions to replace thousands of inadequate legacy guards.
“We have spent decades improving the safety of passenger vehicles, but those structures and restraint systems are rendered inadequate in the event of a trailer rear underrun, which is why we are seeing such a high fatality rate associated with this type of accident. The legislation behind Europe's truck and trailer safety needs to be updated as a matter of urgency.”
Why this matters
The findings affect everyone who shares the road with trucks and trailers in the EU and UK: around 400 people die each year when cars slide underneath trailer rears. The tests reveal that even a five-star-rated car cannot protect occupants if a trailer guard collapses, and that some older automatic braking systems may not even detect trailers. Euro NCAP says tightening the law to match a proven US voluntary standard could save lives.
Terms in This Story
- Rear Underrun Protection System (RUPS)
- A structural guard at the rear of a truck or trailer designed to prevent a car from sliding underneath in a crash.
- Global Vehicle Target (GVT)
- A standardized dummy vehicle used in laboratory tests of automatic emergency braking systems.
- Autonomous Emergency Braking (AEB)
- A system that automatically brakes a vehicle to avoid or mitigate a collision.
- IIHS TOUGHGUARD
- A voluntary safety standard from the US Insurance Institute for Highway Safety for rear underrun guards on trailers.
Summarised from the linked release; details can be imperfect — always verify against the original source.