Draft regulation Impact Statement for Underrun Protection a draft statement inviting discussion and comments from parties affected by the proposed heavy commercial vehicle safety initiative January 2007 Report Documentation Page
Types of underrun crashes and policy prescriptions
Download 5.27 Mb.
|
- Navigate this page:
- Responding to the problem
Types of underrun crashes and policy prescriptionsUnderrun Protection (UP) will not prevent crashes but it will allow the crashworthiness features of the smaller vehicle to function in the event of an underrun collision. Saving the lives of road users depends on the ∆V (closing speed) of the crash, size of the smaller vehicle and any occupant protection features available in the vehicle. Table 5 illustrates the main types of underrun crashes in Australia, in reality a number of combinations are possible with impact areas on the heavy commercial vehicle ranging from front bumper bars, wheels, rear chassis rails, and side chassis rails. An impact with the chassis rail may result in greater intrusion into the space of a passenger vehicle cabin. In case of offset frontal, the smaller vehicle may tend to rotate away from the heavy commercial vehicle thereby reducing injury potential. Table 5 also shows that most OECD countries have some form of mandatory UP, with the European Union leading the table in the mandatory provision for front, side, and rear UP devices for commercial vehicles with a GVM greater than 3.5 tonnes. Table 5 : Types of underrun crashes and policy responses in some countries
Notes: Heavy vehicle GVM/GCM range used in the table is from 20 tonne to 62 tonne. With lower GVMs average decelerations will be lower. In all the above cases cabin intrusion occurs. In crashes where no underrun occurs average deceleration will range from 10g to 15g. The effects have been modelled based on test conditions aligned with ADRs 69 and 73. The EU has 25 member countries and the EU directives enjoy strong following in AGCC and Mercosur countries. Responding to the problemUnderrun crashes present an unusual situation for extracting costs for the provision of Underrun Protection (UP). Heavy commercial vehicle operators in most situations would not derive a great deal of economic benefits from the provision of UP on their vehicles. Other road users, particularly passenger car occupants, would be the principal beneficiaries through reduction in the severity of injuries. It is unlikely that existing market arrangements will be able to correct this externality and influence the provision of UP, as little direct benefits accrue to the provider of such systems. Although European heavy commercial vehicles supplied to the Australian market are provided with UP, this is only because of mandatory requirements in the European Union (EU) countries. While in some cases, the front UP is removed and replaced with a standard bumper-bar, it is uneconomic for other European heavy commercial vehicle wholesalers and importers to offer heavy commercial vehicles without front UP, as it forms part of the front fascia and includes footsteps and other functional devices. As existing market arrangements are not likely to respond to the problem, government intervention of a non-regulatory or regulatory type may be needed. However, any intervention would have to demonstrate a net benefit to the community. Currently, Australia only has Australian Design Rule (ADR) 42/04 – General Safety Requirements, Clause 8 Rear Bumpers for Semi-trailers, to respond to the underrun problem. This ADR is relevant to rear underrun crashes between semi-trailers and other road users. This contrasts with the European Union, Japan, United States, some Latin American and Asian countries that have had regulations in place for some time for side and rear UP and more recently for front UP. In order to reduce fatalities and severity of injuries arising from heavy vehicle underrun crashes, the UP needs to address both dimensional and strength differences between the colliding vehicles. Properly chosen dimensional requirements restrict underruns while strength requirements prevent the system from deflecting under the impact of forces arising from a collision. This prevents underruns and enables any crash protection features in both vehicles to protect occupants. Any of the United Nations Economic Commission for Europe (UNECE) Regulations and corresponding European Economic Commission (EEC) Directives for front, side or rear UP used in the 25 member countries of the European Union, could potentially be adopted in Australia. As these requirements are mandatory, all European heavy vehicle manufacturers design prime-movers, rigid trucks and trailers to meet them. The key features of the Australian Design Rule (ADR), UNECE Regulations, EEC Directives, United States Federal Motor Vehicle Safety Standard (FMVSS) vand other standards relevant to underrun are listed below: UNECE Regulation No. 93 – Front Underrun Protectionvi EEC Directive 2000/40//EC – Motor vehicles with trailers – Front underrun protective devices. This directive is aligned with the requirements of UNECE Regulation No. 93vii Side Underrun Protection Standards UNECE Regulation No. 73 – Lateral protection of trailers and semi-trailer goods vehicles provides side underrun requirementsviii EEC Directive 89/297/EEC – Motor vehicles with trailers – Rear Underrun Protection devices. This directive is aligned with the requirements of UNECE Regulation No. 73ix Rear Underrun Protection Standards ADR 42/04 – General Safety Requirements, Clause 8 Rear Bumpers for Semi-trailers UNECE Regulation No. 58 – Rear Underrun Protection x EEC Directive 70/221/EEC – Motor vehicles with trailers – Rear underrun protection devicesxi. This directive is aligned with the requirements of UNECE Regulation No. 58 FMVSS 223 – Rear impact guards, and FMVSS 224xii National Council of Traffic, Brazil, Regulation Number 152, October 2003 – Rear under ride guards for cargo vehiclesxiii. The UNECE Regulation No. 93 (UNECE R 93) ECE requirements for Front Underrun Protection (FUP) can be met through fitment of a Front Underrun Protection Device (FUPD), or by utilising the vehicle structure as a FUPD. The test that the front UP has to pass for certification consists of three static forces applied one at a time on the centre line of the front UP beam. 80 kN is applied in the centre, 160 kN at a point where the bracket connects the front UP to the chassis beam and finally 80 kN at the corner. Under these forces, there is a limit of 400 mm displacement allowed. The geometry requirements state that the lowermost part of the front UP beam must not exceed 400 mm from the ground and the beam height must not be below 120 mm. The requirements were originally written with a collision speed of 56 km/h. However crash tests with standard European medium family size passenger car in 60 km/h revealed that the injury values of the car occupants were rather low (below HIC 200 - Head Injury Criteria has a limit value of 1000 for survival). The requirements state that the front UP should be "stiff", but in tests an energy absorption of about 60 kJ in the commercial vehicle front compared to about 110 kJ in the passenger car front was observed in European tests. Crash tests performed on smaller cars at 64 km/h have returned lower energy absorption and somewhat higher HIC values, still below the 1000 mark. Table 6 summarizes the test loads for UNECE / EEC and United States front, side and rear UP. Table 6: Test loads for UNECE and US Underrun Standards
Notes: * These test loads apply to vehicles with a GVM >16t, for other vehicles lower values are permitted and are a function of vehicle GVM. ** These test loads apply to vehicles with a GVM >20t, for other vehicles lower values are permitted and are a function of vehicle GVM. Australian Design Rule (ADR) 42/04 – General Safety Requirements contains dimensional requirements but no test load requirements for rear bumpers for semi-trailers. Instead it requires that the rear cross member has at least the strength of steel tubing of 100mm diameter and 8mm wall thickness, and that an equivalent force path is available from the cross member to the main vehicle members. Directory: barreirastecnicas -> pontofocal -> textos -> regulamentos pontofocal -> Ind- 2001 0382 nl- en regulamentos -> Kenya standard ks 06-77: 1978 ics 13. 340 Download 5.27 Mb. Share with your friends:
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||