Intoroads, through the Technical Committees, is currently engaged in the development of a number of projects relative to the use of road equipment, with particular reference to restraint devices.
Influence of light vehicle models in the determination of accelerometric indices in EN 1317 (WG1)
Can the criteria dictated by the EN 1317 standard for the evaluation of vehicle occupant safety, defined in 1998, still be considered representative and in line with the evolution of vehicles and the safety criteria adopted by the automotive industry?
Examination of hundreds of crashes have shown that the accelerometer indices provided in EN 1317 are strongly influenced by the vehicle, which, moreover, the standard does not fully define, and that, contrary to what would be expected, these indices worsen in the case of tests and performed on more modern vehicles.
Thus, according to EN 1317, modern vehicles would be less safe, with respect to occupants, than older ones.
By conducting about 20 specific crash tests on vehicles put on the market in the last 30 years and reviewing data from more than 100 crash tests, Intoroads is conducting a study to evaluate the influence of the vehicle in the parameters provided by the standard and the development of parameters independent of the mechanical characteristics of the vehicles
Identification of Vehicles representative of the fleet on the road in Europe as of 2023 – updated (WG2)
Are the vehicle characteristics provided by EN 1317 for crash testing actually representative of the traffic circulating on European roads today?
Can a vehicle weighing 900 kg be considered representative of the light vehicles on the road? And are the permitted heavy vehicles, particularly buses, representative of those on the road? And, in any case, can the tests performed with such vehicles be considered sufficiently precautionary?
The U.S. tests, for example, in addition to a light-vehicle test and a heavy-vehicle test, include a test with a Pickup truck, a vehicle particularly representative of American traffic, which is often the most challenging test for the device.
With the data available on vehicles circulating in Europe, Intoroads is conducting a study to analyze the characteristics of European traffic in order to understand whether the vehicles provided for in EN 1317 are indeed representative or whether it might not also be appropriate to evaluate the behavior of the barrier for impacts with different vehicles
Scenarios of crash tests provided by EN 1317 (WG3)
EN 1317 provides for impacts with impact angles of 15 and 20 degrees, considering them to be sufficiently precautionary compared to the angles of impacts occurring on roads. The assessment is made in terms of energy. But would a vehicle impacting a barrier with a lower energy than EN 1317, but, for example, at a greater angle, be contained by the barrier? Are the barriers designed only to withstand impacts with the angles provided in the standard, or can they provide acceptable performance even for impacts of lower energy but with greater angles?
Also, are the containment classes provided in EN 1317, in light of 30 years of experience, adequately calibrated? For example, is test TB81, provided for class H4, which develops a nominal energy of 724 KJ, actually significantly more critical than test TB61, provided for class H3, which develops a nominal energy of 462 KJ?
From examining hundreds of crashes and with the help of a virtual crash test campaign after calibration of real tests, Intoroads is analyzing the behavior of barriers put on the market in the last 30 years with different but still representative test scenarios
TECHNICAL CRITERIA FOR CE
Guidelines for issuing Certificates of Constancy of Performance (WG4)
The placing on the market of a restraint device is now subject to the issuance of a Certificate of Constancy of Performance, issued by a Notified Body recognized by the European Commission, which are required to be accredited under EN 17065. The spirit of certification is to allow products to be placed on the European market that all meet the same technical directives. But do the more than 50 Notified Bodies in Europe operate with essentially similar criteria? And do they have the appropriate expertise to untangle the complex regulatory and technical landscape for restraint devices? Are the reference standards and Position Papers interpreted in a substantially equivalent manner? And are product modifications, which are in high demand because of the high cost of testing, handled with shared technical criteria that ensure that they do not actually affect device performance?
If this were not the case, as in fact it is not, products placed on the market cannot be considered equivalent but would depend on the criteria adopted by the Notified Body, to the detriment of safety.
From an in-depth study of the technical standards and Positio Papers issued by CEN, Intoroads is preparing a guideline, to be shared with the main European Notified Bodies, that analyzes all aspects of certification and provides industry operators with an unambiguous reference document that limits, especially from a technical point of view, excessive deviations from the current standards of the different Notified Bodies and the deviations, in order to place on the European market products that meet essentially the same criteria and can guarantee the highest safety standards currently possible.
Integration of real-life crash tests with virtual crash tests (WG5)
Computational mechanics is making great strides in its reliability, and although, at least at present, it cannot replace crash tests even in part, it can, however, provide interesting insights for analyzing d uro scenarios other than the standard ones. What happens, for example, if the point of impact varies from the point of crash? Or if the device length or terminal type changes? And for a crash-tested transition, what happens if the upstream and downstream barriers change?
For computational mechanics to be truly effective, however, they need to be performed by trained personnel, in line with the requirements of EN 16303 and, most importantly, the test scenarios must be truly representative and provide a meaningful enhancement of the safety of the device.
Intoroads is analyzing, for the different situations where computational mechanics can provide an additional contribution, a set of scenarios and criteria to be shared with operators that can constitute a guideline for the use of numerical simulations, using them in a timely and effective manner.