In September 2021, the third and most recent revision to the UN's regulations on truck underrun protection came into force for all newly registered vehicles, which had already applied since 2019 for new type-approved vehicles. ECE-R58.03, the latest version of the R58 regulations, as they are more commonly known, sets standards for the design, dimensions and strength of rear underrun protection devices (RUPDs). These devices are designed to avoid serious injuries for motorists by preventing smaller vehicles like cars from becoming lodged underneath a truck or a trailer in rear-end collisions – so it's essential to be aware of the standards your RUPDs need to comply with to keep other road users safe.
Even though the latest revision to R58 is a few years old, the continuing registration of new trucks and trailers and certain national and regional exemptions to the regulations mean the industry is still transitioning. In this article, we'll explain the basics of the latest R58 regulations and their impact on our industry and hopefully help you and your company fully comply with the law.
What are the R58 regulations?
These regulations come from the UN, and they apply in all 56 countries that are a part of the UN Economic Commission for Europe (UNECE) – all European countries and several others in Central Asia, the Middle East and North America. Simply put, they set rules for the design of RUPDs and how they should work. Although they ultimately affect anyone who operates vehicles fitted with RUPDs, the regulations have a big impact on RUPD manufacturers, vehicle manufacturers that type approve vehicles that will be fitted with RUPDs, and vehicle manufacturers that produce vehicles designed to protect against underrunning without a separate RUPD.
The regulations cover RUPDs that will be fitted to vehicles in the categories M, N and O – for us, that generally means light or heavy goods vehicles and trailers.
The demands of the R58 regulations aim to raise the level of protection an RUPD offers in a collision. So, measurements like how much of the vehicle's width an RUPD covers, the ground clearance, the height, the forces it can withstand and the amount it deforms in a collision are covered in the regulations. Beyond the design of the RUPD itself, the regulations also cover the requirements these devices must meet in tests before they can be certified and sent out on the road.
Broadly speaking, the third revision to the R58 regulations made all these requirements stricter. Today, RUPDs need to provide a greater area of protection and withstand greater forces while also meeting tougher test requirements. Let's look at the specifics.
What does the third revision to the R58 regulations involve?
The entire text of the latest R58 regulations is over 20 pages long, so we won't summarise every single detail here. However, these are the main changes that may impact your equipment:
- Lower ground clearance – The distance between the RUPD and the road surface must now be smaller. Now, RUPD ground clearance has been aligned with the typical front bumper height of passenger cars, creating a more effective protection and reducing the risk even further of a car becoming wedged under a vehicle and crushed in a rear-end collision.
- Shorter rear overhang – The distance between the rear end of the truck or trailer and the RUPD. If this distance is too long, the RUPD alone becomes less effective at reducing the severity of accidents.
- Tighter limits around deformation – Related to the overhang question, the deformation of an RUPD after a collision now must be considered much more. The maximum allowed overhang is 400mm, but the deformation caused by a collision must also be considered – meaning the true maximum overhang will be less.
- Increased dimensions – RUPDs that comply with the latest version of R58 are generally larger than their predecessors. For example, the profile height of the RUPD beam has been increased to improve the degree of underrun protection in a rear-end collision.
- Greater test capacities – During testing of RUPDs, the centre of the beam profile, the support brackets, and the outer edge of the beam are subjected to pushing forces. After the latest R58 revisions, these test forces have almost been doubled, meaning new RUPDs need to be able to withstand larger impacts.
- Stricter, more realistic testing protocols – Previously, these kinds of tests were generally simulated and based on calculations of the capacities of the materials and the forces they were placed under. Today, the rules around these calculation-based tests are more stringent and they now must be validated with physical tests.
What do the new R58 regulations mean for me?
Many of these changes have the biggest effect on manufacturers of RUPDs. However, manufacturers and fleets have also felt the impact since the latest revision to the regulations came into force.
The larger dimensions and higher capacities demanded by the new regulations mean compliant RUPDs have a higher total weight and size than before, which has created challenges around weight distribution and design for some manufacturers. This has also been an issue for mechanics, who have also had to get familiar with new mounting routines and more severe chassis damage that newer RUPDs can cause in a collision.
It can also be tricky in some cases to manage a mixed fleet of older and newer vehicles with different RUPD designs. This can potentially lead to inefficiencies in maintenance and spare parts sourcing. However, pre-R58.03 RUPDs can be completely replaced with new models without the need for a new inspection approval.
Keeping up with the latest regulations isn’t easy when you have all your daily tasks to keep up with. As usual, the best advice if you’re in doubt is to source RUPDs from a reputable supplier with the right expertise and certifications. Many of these suppliers will also be able to advise you on the best RUPD alternatives depending on your applications and requirements, especially if you’re in the process of updating a fleet with fully compliant vehicles.
If you need any support or guidance around the current R58 regulations or any other legal requirements that affect our industry, don’t hesitate to get in touch with us, or take a look at our full range of underrun protection devices to see what products we have to offer.
