{"id":"F2006L01279","name":"Vehicle Standard (Australian Design Rule 28/01 – External Noise of Motor Vehicles) 2006","slug":"vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":436423,"registerId":"commonwealth-F2006L01279-current","compilationNumber":null,"startDate":"2026-04-12","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"0.1","sectionType":"part","heading":"NAME OF STANDARD","content":"# 0.1 NAME OF STANDARD\n\n0.1.1 This Standard is the Vehicle Standard (Australian Design Rule 28/01 – External Noise of Motor Vehicles) 2006.\n\n0.1.2 This Standard may also be cited as ADR 28/01.","sortOrder":0},{"sectionNumber":"0.2","sectionType":"part","heading":"COMMENCEMENT","content":"# 0.2 COMMENCEMENT\n\n0.2.1 This Standard commences on the day after it is registered.","sortOrder":1},{"sectionNumber":"0.3","sectionType":"part","heading":"REPEAL","content":"# 0.3 REPEAL\n\n0.3.1 This Standard repeals each vehicle standard with the name ADR 28/01, and each amendment of such a standard, that is:\n\n (a) made under section 7 of the Motor Vehicles Standard Act 1989; and\n\n (b) in force at the commencement of this Standard.\n\n0.3.2 This Standard also repeals each instrument made under section 7 of the Motor Vehicles Standard Act 1989 that creates or amends a vehicle standard with the name ADR 28/01, if there are no other vehicle standards created by that instrument that are still in force at the commencement of this Standard.","sortOrder":2},{"sectionNumber":"1","sectionType":"part","heading":"SCOPE","content":"# 1 SCOPE\n\n1.1 The function of this ADR is to define limits on external noise generated by motor vehicles in order to limit the contribution of motor traffic to community noise.","sortOrder":3},{"sectionNumber":"2","sectionType":"part","heading":"APPLICABILITY AND IMPLEMENTATION","content":"# 2 APPLICABILITY AND IMPLEMENTATION\n\n2.1 ADR 28/01 applies to the design and construction of vehicles as set out in the following table.\n\n\n\n| VEHICLE CATEGORY | VEHICLE CATEGORY CODE | MANUFACTURED ON OR AFTER |\n| --- | --- | --- |\n| Motor Tricycle | LE
LEP
LEG |
1 July 1992
1 July 1992 |\n| Passenger Car | MA | 1 January 1992 |\n| Forward-control Passenger Vehicle | MB | 1 January 1992 |\n| Off-road Passenger Vehicle | MC | 1 January 1992 |\n| Light Omnibus | MD | 1 July 1992 |\n| Heavy Omnibus
up to 270 kW
over 270 kW | ME
ME1
ME2 |
1 July 1992
1 July 1993 |\n| Light Goods Vehicle | NA | 1 January 1993 |\n| Medium Goods Vehicle | NB | 1 July 1992 |\n| Heavy Goods Vehicle
up to 270 kW
over 270 kW | NC
NC1
NC2 |
1 July 1992
1 July 1993 |\n\n\n2.2 Vehicles complying with ADR 83/00 External Noise, need not comply with this ADR.","sortOrder":4},{"sectionNumber":"28.1","sectionType":"part","heading":"DEFINITIONS","content":"# 28.1 DEFINITIONS\n\n28.1.1 ‘Component’ means one of the individual constituent parts whose assembly constitutes the ‘Noise Reduction System’.\n\n28.1.1.1 These ‘Components’ are, in particular, the exhaust manifold, the exhaust piping, the expansion chamber, the silencer proper. If the engine intake is equipped with an air filter and the filter’s presence is essential to ensure observance of the prescribed sound level limits, the filter must be regarded as a ‘Component’ of the ‘Noise Reduction System’.\n\n28.1.2 ‘Diesel Engine’ means an internal combustion engine which operates on the compression-ignition principle.\n\n28.1.3 ‘Engine Speed at Maximum Power’ (‘ESMP’) means the speed at which the engine develops maximum power (r/min).\n\n28.1.4 ‘Net Engine Power’ (‘NEP’) means the engine power expressed in kW (ECE) and measured:\n\n28.1.4.1 for positive-ignition engines, by the method described in Annex 8 to UN ECE Regulation No 15 - “Emission of Gaseous Pollutants”:\n\n28.1.4.2 for ‘Diesel Engines’, by the method described in Annex 10 to UN ECE Regulation No. 24 - “Diesel Engine Pollutant Emissions”,\n\n28.1.5 ‘Noise Reduction System’ means a complete set of ‘Components’ necessary for limiting the noise made by a motor vehicle and its exhaust.\n\n28.1.6 ‘Off-road Use’ means the type of use requiring a vehicle to have the special design features listed in the definition of ‘Off-road Passenger Vehicle’.\n\n28.1.7 ‘Spark Ignition’ means positive ignition.","sortOrder":5},{"sectionNumber":"28.2","sectionType":"part","heading":"SPECIFICATIONS","content":"# 28.2 SPECIFICATIONS\n\n28.2.1 General specifications\n\n28.2.1.1 The vehicle, its engine and its ‘Noise Reduction System’ shall be so designed, constructed and assembled as to enable the vehicle in normal use, despite the vibration to which it may be subjected, to comply with the provisions of this vehicle standard.\n\n28.2.1.2 The ‘Noise Reduction System’ and its ‘Components’ shall be so designed, constructed and assembled as to resist the corrosive action to which the vehicle is exposed.\n\n28.2.2 Specifications regarding sound levels\n\n28.2.2.1 Methods of measurement.\n\n28.2.2.1.1 The noise made by the vehicle shall be measured by the two methods described in the Annex for the vehicle in motion and for the vehicle when stationary.[[1]](#_ftn1)\n\n28.2.2.1.2 The values so obtained shall be entered in the test report for the vehicle.\n\n28.2.2.2 Sound level limits.\n\n28.2.2.2.1 The sound level measured by the two methods described in the Annex for vehicles in motion and for stationary vehicles shall not exceed (except as prescribed) the limits contained in Table 1.","sortOrder":6},{"sectionNumber":"28.3","sectionType":"part","heading":"ALTERNATIVE STANDARDS","content":"# 28.3 ALTERNATIVE STANDARDS\n\n28.3.1 For vehicles other than Goods Vehicles and Omnibuses the technical requirements of UN ECE Regulation 51/01 or 51/02 - “Vehicle Noise Emissions” (as harmonized with EEC Directives 84/424 or 92/97- “The Sound Level of Vehicles”) shall be deemed to be equivalent to the technical requirements of this Vehicle standard provided that the noise level recorded during the test on the vehicle while stationary does not exceed the appropriate limit listed in Table 1.\n\n28.3.2 For Goods Vehicles and Omnibuses the technical requirements of UN ECE Regulation 51/01 or 51/02 (as harmonized with EEC Directives 84/424 or 92/97) shall be deemed to be equivalent to the technical requirements of this Vehicle standard relating to tests on vehicles in motion. Additional evidence of compliance with the appropriate stationary test requirements of this Vehicle standard will be required.\n\n28.3.3 The test site requirements contained in ADR 28/00 clause 28.5 shall be deemed equivalent to clause 2.1 in Annex A of this Vehicle standard.\n\n\nTable 1 - Sound Level Limits dB(A)\n\n- VEHICLES IN MOTION STATIONARY VEHICLES\n- VEHICLE VEHICLE TYPE Spark Ignition Spark Ignition Diesel\n- CATEGORY Engines and Engines Engines\n- CODE Direct injection Indirect injection Exhaust Outlet Height Exhaust Outlet Height\n- Diesel Engines Diesel Engines <1500 mm >1500 mm <1500 mm >1500 mm\n- LE Motor Tricycle\n- LEP 78 77 90 90 90 90\n- LEG 79 78 89 85 99 95\n- MA Passenger Cars 78 77 90 90 90 90\n- MB Forward Control Passenger Vehicles\n- GVM < 2 tonne 78 77 90 90 90 90\n- GVM > 2 tonne\n- On Road Use 78 77 90 90 90 90\n- Off Road Use\n- NEP < 150 kW 79 78 90 90 90 90\n- NEP > 150 kW 80 79 90 90 90 90\n- MC Off Road Passenger Vehicles\n- GVM < 2 tonne 78 77 90 90 90 90\n- GVM > 2tonne\n- NEP < 150 kW 79 78 90 90 90 90\n- NEP > 150 kW 80 79 90 90 90 90\n- MD Light Omnibuses\n- GVM < 2 tonne 79 78 89 85 99 95\n- GVM > 2 tonne < 3.5 tonne\n- On Road Use 80 79 89 85 99 95\n- Off Road Use\n- NEP < 150 kW 81 80 89 85 99 95\n- NEP > 150 kW 82 81 89 85 99 95\n- GVM > 3.5 tonne < 5 tonne\n- On Road Use\n- NEP < 150 kW 80 80 95 91 101 97\n- NEP > 150 kW 83 83 95 91 101 97\n- Off Road Use\n- NEP < 150 kW 81 81 95 91 101 97\n- NEP > 150 kW 85 85 95 91 101 97\n- ME Heavy Omnibuses\n- GVM > 5 tonne < 12 tonne\n- On Road Use\n- NEP < 150 kW 80 80 95 91 101 97\n- NEP > 150 kW 83 83 95 91 101 97\n- Off Road Use\n- NEP < 150 kW 81 81 95 91 101 97\n- NEP > 150 kW 85 85 95 91 101 97\n- GVM > 12 tonne\n- On Road Use\n- NEP < 150 kW 80 80 95 91 103 99\n- NEP > 150krn < 270 kW 83 83 95 91 103 99\n- NEP > 270 kW 86 86 95 91 103 99\n- Off Road Use\n- NEP < 150 kW 81 81 95 91 103 99\n- NEP > 150 kW < 270 kW 85 85 95 91 103 99\n- NEP > 270 kW 86 86 95 91 103 99\n- NA Light Goods Vehicles\n- GVM < 2 tonne 79 78 89 85 99 95\n- GVM > 2 tonne < 3.5 tonne\n- On Road Use 80 79 89 85 99 95\n- Off Road Use\n- NEP < 150 kW 81 80 89 85 99 95\n- NEP > 150 kW 82 81 89 85 99 95\n- NB Medium Goods Vehicles\n- GVM >3.5 tonne < 12 tonne\n- On Road Use\n- NEP <75 kW 81 81 95 91 101 97\n- NEP > 75 kW < 150 kW 83 83 95 91 101 97\n- NEP > 150 kW 84 84 95 91 101 97\n- Off Road Use\n- NEP < 75 kW 82 82 95 91 101 97\n- NEP > 75 kW < 150 kW 84 84 95 91 101 97\n- NEP > 150 kW 86 86 95 91 101 97\n- NC Heavy Goods Vehicles\n- GVM > 12 tonne\n- On Road Use\n- NEP < 75 kW 81 81 95 91 103 99\n- NEP < 75 kW < 150 kW 83 83 95 91 103 99\n- NEP > 150 kW < 270 kW 84 84 95 91 103 99\n- NEP > 270 kW 87 87 95 91 103 99\n- Off Road Use\n- NEP < 75 kW 82 82 95 91 103 99\n- NEP > 75 kW < 150 kW 84 84 95 91 103 99\n- NEP > 150 kW < 270 kW 86 86 95 91 103 99\n- NEP > 270 kW 87 87 95 91 103 99","sortOrder":7},{"sectionNumber":"ANNEX A — METHODS AND INSTRUMENTS FOR ME","sectionType":"part","heading":"ANNEX A — METHODS AND INSTRUMENTS FOR MEASURING THE NOISE MADE BY MOTOR VEHICLES","content":"# ANNEX A – METHODS AND INSTRUMENTS FOR MEASURING THE NOISE MADE BY MOTOR VEHICLES\n\n1. Measuring Instruments\n\n1.1 A sound level meter of high precision complying at least with the specifications of Publication No 651 (1979) - “Precision sound level meters” of the International Electrotechnical Commission (IEC), or Type 1 of Australian Standard 1259-1982 - “Sound Level Meters”, concerning the characteristics of sound level meters, shall be used. Measurement shall be carried out with a weighting network and a time constant conforming to “curve A” and the “fast response” respectively.\n\n1.2 The sound level meter shall be calibrated against a standard noise source immediately before and after each series of test runs. If the meter reading obtained from either of these calibrations deviates by more than 1dB(A) from the corresponding reading taken at the time of the last free-field calibration the test shall be considered invalid. The actual deviation shall be recorded.\n\n1.3 The rotational speed of the engine shall be measured by an independent tachometer whose accuracy is within 3 per cent of the actual speed of rotation.\n\n\n\n2. Procedure for Vehicles in Motion\n\n(Refer to diagram - Section 4)\n\n2.1 Site for tests on vehicles in motion.\n\n2.1.1 The measurements shall be made at an open site where the ambient and wind noise levels are at least 10 dB(A) below the noise level being measured. The site may take the form of an open space of 25 m radius having a central part of at least 10 m radius, practically level, consisting of concrete, asphalt or similar material and not covered with powdery snow, tall grass, loose soil, ashes or the like. During the test no one shall be in the measurement area except the observer and the driver. Their presence must have no influence on the meter reading.\n\n2.1.2 The surface of the test track used to measure the noise of vehicles in motion shall be such as not to cause excessive tyre noise.\n\n2.1.3 Measurements shall not be made under adverse weather conditions. Any sound peak which appears to be unrelated to the characteristics of the general sound level of the vehicle shall be ignored in taking the readings. If a wind guard is used, its influence on the sensitivity and the directional characteristics of the microphone shall be taken into account.\n\n\n\n2.2 Vehicle condition.\n\n2.2.1 Measurements shall be made on unladen vehicles and, except in the case of non-separable vehicles, without trailer or ‘Semi-trailer’.\n\n2.2.2 The tyres of the vehicle shall be of the correct size and shall be inflated to the correct pressure(s) (etc.) for the vehicle in its unladen condition.\n\n2.2.3 Before the measurements are begun, the engine shall be brought to its normal operating conditions as regards: temperatures, tuning, fuel, sparking plugs, carburettor(s), etc. as appropriate.\n\n2.2.4 If the vehicle is fitted with more than two-wheel drive, it shall be tested in the drive which is intended for normal road use.\n\n2.2.5 If the vehicle is equipped with devices which are not necessary for its propulsion, but which are used whilst the vehicle is in normal service on the road, those devices shall be in operation in accordance with the specifications of the ‘Manufacturer’.\n\n\n\n2.3 Measurement of noise of vehicles in motion.\n\n2.3.1 General conditions of test.\n\n2.3.1.1 At least two measurements shall be made on each side of the vehicle.\n\nPreliminary measurements may be made for adjustment purposes, but shall be disregarded.\n\n2.3.1.2 The microphone shall be situated 1.2 m + 0.1 m above the test site surface at a\n\ndistance of 7.5 m + 0.2 m from the path of the vehicle’s centreline, measured along the perpendicular (PP’) to that line.\n\n2.3.1.3 Two lines, AA’ and BB’, parallel to line PP’ and situated respectively 10m\n\nforward and 10m rearward of that line shall be marked out on the test site surface. The vehicle shall approach line AA’ at a steady speed as specified below. When the front of the vehicle reaches the line AA’, the throttle shall be fully opened as rapidly as practicable and held in the fully-opened position until the rear of the vehicle crosses line BB’, the throttle shall then be closed again as rapidly as possible.\n\n2.3.1.4 In the case of articulated vehicles consisting of two non-separable units regarded\n\nas a single vehicle, the semi-trailer shall be disregarded in determining when line BB’ is crossed.\n\n2.3.1.5 The maximum sound level recorded during this procedure shall constitute the\n\nresult of the measurement.\n\n\n\n2.3.2 Method of conducting the test.\n\n2.3.2.1 Symbols used.\n\nThe letter symbols used in this paragraph have the following meanings:\n\nS ’ESMP,’\n\nNA uniform engine rotational speed at the approach of line AA’,\n\nVA uniform vehicle speed at the approach of line AA’.\n\n2.3.2.2 Vehicle with no gearbox.\n\nFor vehicles with no gearbox or with no transmission controls, the uniform speed at the approach of line AA’ will be such that either:\n\nNA = ¾ S and VA < 50 km/h,\n\nor\n\nVA = 50 km/h\n\nand within the specified range of +5, -1 km/h of that speed for each test.\n\n2.3.2.3 Vehicle with a manually-operated gearbox.\n\n2.3.2.3.1 Approach speed.\n\nThe vehicle will approach the line AA’ with uniform speed such that either :\n\n NA = 3/4 S and VA < 50 km/h,\n\nor\n\nVA = 50 km/h.\n\nand within the specified range of +5, -1 km/h of that speed for each test.\n\n2.3.2.3.2 Choice of gear ratio.\n\n2.3.2.3.2.1 Vehicles of categories MA and NA fitted with a gearbox having four or less\n\nforward gears shall be tested in second gear.\n\nVehicles of categories MA and NA fitted with a gearbox having more than four forward gears shall be tested successively in second and third gear. The average value of the sound levels recorded for these two conditions shall be reported. However vehicles of category MA having more than four forward gears and equipped with an engine having \n\n‘NEP’ 140 kW(ECE) and a permissible maximum power to maximum mass ratio 75 kW(ECE) per tonne shall be tested only in third gear, provided that the speed at which the rear of the vehicle passes line BB’ in third gear is greater than 61 km/h.\n\nVehicles of categories other than MA and NA whose number of forward gears is X (including those obtained by way of an auxiliary transmission or a multi-gear axle) will be tested successively with the gear selection equal to or higher than X/2. The condition giving the highest noise level shall be reported.\n\n2.3.2.3.2.3.1 If the ratio X/2 is not an integer, the next higher gear shall be selected.\n\n\n\n2.3.2.4 Vehicles with automatic transmission.\n\n2.3.2.4.1 Vehicles without a manual selector.\n\n2.3.2.4.1.1 Approach speed.\n\nThe vehicle shall approach the line AA’ at various uniform speeds of 30, 40 and 50 km/h (or at 3/4 of the maximum on-road speed if this value is lower). The condition giving the highest noise level shall be reported and within the specified range of +5, -1 km/h of that speed for each test.\n\n\n\n2.3.2.4.2 Vehicles equipped with a manual selector.\n\n2.3.2.4.2.1 Approach speed.\n\nThe vehicle shall approach the line AA’ at a steady speed corresponding to either:\n\nNA = ¾ S and VA <50 km/h,\n\nor\n\nVA = 50 km/h and NA < ¾ S\n\nand within the specified range of +5, -1 km/h of that speed for each test.\n\nHowever, if during the test, in the case of vehicles having more than two separate gears, there is a down-shift to first gear, this down-shift may be avoided at the ‘Manufacturer’s’ choice either by:\n\nincreasing the speed of the vehicle VA to a maximum of 60km/h,\n\nor\n\nmaintaining the speed VA at 50 km/h, with the fuel supply to the engine limited to 95 per cent of the supply necessary for full load.[[2]](#_ftn2)\n\n2.3.2.4.2.2 Position of the manual selector\n\nThe test shall be conducted with the selector in the position recommended by the ‘Manufacturer’ for normal driving.\n\n2.3.2.4.2.3 Auxiliary gears.\n\nIf the vehicle is fitted with an auxiliary manual transmission or multi-gear axle, the position used for normal urban driving shall be used. In all cases, the special selector positions for slow movement, parking, or braking shall be excluded.\n\n\n\n2.4 Interpretation of results for vehicles in motion.\n\n2.4.1 The measurements of the noise emitted by the vehicle in motion shall be considered valid if the difference between the two consecutive measurements on the same side of a vehicle is not more than 2 dB(A).\n\n2.4.2 To allow for lack of precision in the measuring instrument the figures read from it during measurement shall be reduced by 1 dB(A).\n\n2.4.3 The figure reported shall be that corresponding to the highest sound level. Should that figure exceed by more than 1dB(A) the maximum sound level authorised for the category of vehicle tested a second series of two measurements shall be made. Three out of the four results so obtained must fall within the prescribed limits.\n\n\n\n3. Procedure for Stationary Vehicles\n\n(Refer to diagram - Section 4)\n\n3.1 Requirements for tests on stationary vehicles.\n\n3.1.1 Tests on stationary vehicles (exhaust noise tests) should ideally be carried out consecutively with the tests on the same vehicle in motion.\n\n3.1.2 The measurements shall be made at an open site where the ambient and wind noise levels are at least 10 dB(A) below the noise level being measured. The site may take the form of an open space where a rectangle with sides no closer than 3 m from the extremities of the vehicle can be described. The test site surface should be practically level, consisting of concrete, asphalt or similar material and not covered with powdery snow, tall grass, loose soil, ashes or the like.\n\n3.1.3 Measurements shall not be made under adverse weather conditions. Any sound peak which appears to be unrelated to the characteristics of the general sound level of the vehicle shall be ignored in taking the readings. If a wind guard is used, its influence on the sensitivity and the directional characteristics of the microphone shall be taken into account.\n\n3.1.4 Whilst testing is in progress no person other than any occupants of the vehicle shall be within 1 m of the microphone in use. No person or object other than the person conducting the test and an observer or the objects necessary for the performance of the test shall be within 3m of the microphone in use.\n\n3.1.5 Before the measurements are begun, the engine shall be brought to its normal operating conditions as regards: temperatures, tuning, fuel, sparking plugs, carburettor(s), etc. as appropriate.\n\n3.1.6 The use of special acoustic shielding may be permitted in unusual cases. Refer to paragraph\n\n\n\n3.2 Microphone position.\n\n3.2.1 The microphone shall be directed towards the orifice of the exhaust outlet and shall be supported by a tripod or similar device not providing excessive acoustic reflection.\n\n3.2.2 The nominal axis of maximum sensitivity of the microphone shall be substantially parallel to the test site surface.\n\n3.2.3 The height of the microphone above the test site surface shall be equal to that of the orifice of the exhaust outlet + 25 mm but shall not be less than 200 mm above the test site surface.\n\n3.2.4 The distance of the microphone from the orifice of the exhaust outlet shall be:\n\n3.2.4.1 in the case of a ‘Goods Vehicle’ or ‘Omnibus’ 1050 mm + 50 mm,\n\n3.2.4.2 in the case of any other vehicle 525 mm +25 mm.\n\n\n\n3.2.5 For vehicles fitted with one exhaust outlet which is at a height above the test site surface of less than 1500 mm, the nominal axis of maximum sensitivity of the microphone shall make an angle of 45 degrees + 10 degrees with the principal direction of the gas flow from the exhaust outlet.\n\n3.2.5.1 In selecting this microphone position the microphone shall be placed so that the\n\ngreatest possible distance is achieved between it and the vehicle.\n\n\n\n3.2.6 For vehicles fitted with one exhaust outlet which is at a height above the test site surface of at least 1500 mm, the nominal axis of maximum sensitivity of the microphone shall make an angle of 90 degrees + 10 degrees with the longitudinal centreline of the vehicle.\n\n3.2.6.1 In selecting this microphone position the microphone shall be placed so that the\n\ngreatest possible distance is achieved between it and the vehicle.\n\n\n\n3.2.7 For vehicles fitted with two or more exhaust outlets spaced less than 500 mm apart and connected to a single silencer only one microphone position shall be used. That position shall be selected in accordance with the procedure described in the preceding paragraphs in respect of an exhaust outlet which results in the microphone being at the greatest possible distance from the vehicle.\n\n3.2.8 For vehicles fitted with two or more exhaust outlets connected to separate silencers or spaced more than 500 mm apart, each exhaust outlet shall be treated separately as if it was the only one.\n\n3.2.9 Notwithstanding anything to the contrary in the preceding paragraphs if the microphone positioning procedures result in no suitable position due to an obstruction being part of the vehicle or in an obstruction being directly between the microphone and the exhaust outlet, the requirements of paragraphs 3.2.2 and 3.2.3 may be varied.\n\n\n\n\n\n3.3 Vehicle operation and noise measurement.\n\n3.3.1 The vehicle shall be stationary with the transmission in neutral or, in the case of a vehicle with automatic transmission, with the gear selector in the “park” position if such a position is provided.\n\n3.3.2 In the case of Goods Vehicles and Omnibuses powered by a ‘Diesel Engine’ the engine shall be operated in accordance with the following procedure.\n\n3.3.2.1 With the engine at idling speed the accelerator pedal of the vehicle shall be\n\ndepressed as rapidly as possible and kept fully depressed until the speed of the engine is substantially stable at maximum (or governed) speed. The accelerator pedal shall then be permitted to return to its original position as rapidly as possible and left in that position until the engine has returned to idling speed.\n\n3.3.2.2 A single noise level measurement shall be made for each microphone position in\n\nuse by noting the maximum noise level indicated during this procedure.\n\n\n\n3.3.3 In the case of all other vehicles the engine shall be operated in accordance with the following procedure.\n\n3.3.3.1 The engine shall be brought to 3/4 ‘ESMP’ and stabilised at that speed.\n\n3.3.3.2 A single noise level measurement shall then be made.\n\n\n\n3.3.4 The specified procedure shall be repeated until four consecutive readings having a range less than or equal to 1dB(A) are obtained for each microphone position used.\n\n\n\n3.4 Interpretation of results for stationary vehicles.\n\n3.4.1 Where one microphone position is used the noise level of the vehicle shall be the arithmetic mean of the four readings specified in paragraph 3.3.4.\n\n3.4.2 When the sound level of the vehicle has been calculated, non-integer results shall be rounded down to the nearest whole decibel.\n\n3.4.3 Where more than one microphone position is used the noise level at each microphone position shall be determined as if it was the only one. The noise level of the vehicle shall be the higher or highest noise level so calculated.\n\n3.4.4 If the microphone position is less than 1m from the engine compartment of the vehicle the calculated noise level shall be reduced by 2dB(A) unless the provisions of paragraph 3.4.5 have been invoked.\n\n3.4.5 Where the mechanical noise of the vehicle (for example engine or transmission noise) can be shown to increase the measured noise level by 2dB(A) or more, special acoustic shielding may be fitted to mask this source so that the test is carried out on the exhaust noise alone.\n\n3.4.5.1 Such shielding shall not interfere with the normal acoustic properties of the\n\n‘Noise Reduction System’.\n\n3.4.5.2 Where such shielding is used both noise levels (with and without the shielding)\n\nshall be reported. The noise level with the shielding in place shall be used to assess the vehicle’s compliance.\n\n3.4.5.3 Where such shielding is used the provisions of paragraph 3.4.4 shall not apply.\n\n\n4. TEST SITE LAYOUT AND TYPICAL MICROPHONE LOCATIONS\n\n1. Vehicle in motion\n2.  Stationary Vehicles\n\n\n","sortOrder":8}],"analysis":{"flash_summary":{"complexity_score":7,"scope_assessment":{"changed":false,"description":"This instrument consolidates and restates ADR 28/01 provisions (it expressly repeals prior instruments with the same name) rather than materially expanding scope beyond the ADR’s traditional purpose of setting external vehicle noise limits and test methods (see 0.3 and 1.1). It keeps the core focus on design/construction requirements and on‑vehicle noise measurement, and includes equivalence routes to UN ECE Regulation 51/01/02 and an exemption for vehicles already complying with ADR 83/00 (28.3; 2.2). Those equivalence clauses reduce duplication but do not broaden the standard’s substantive reach beyond regulating external vehicle noise at point of manufacture/certification."},"complexity_factors":["Multiple vehicle categories with manufacture date triggers (2.1)","Extensive Table 1 with many vehicle subcategories and different dB(A) thresholds (Table 1)","Around 7 defined terms in the Definitions (28.1.1–28.1.7) with cross‑links into technical rules","Detailed two‑method measurement regime (vehicles in motion and stationary) with many conditional procedures (Annex A Parts 2 and 3)","Numerous gear/drive/gearbox conditional rules (2.3.2.2–2.3.2.4) including special cases and averaging rules","Calibration and repeatability rules requiring instrument adjustments and multi‑run acceptance criteria (Annex A 1.2; 2.4; 3.3.4–3.4.4)","Cross‑references and equivalence to international instruments (UN ECE Reg 51/01/02 and ADR 83/00) (28.3; 2.2)","Fallbacks and discretionary variations for microphone placement and shielding (Annex A 3.2.9; 3.4.5)"],"plain_english_summary":"**What this standard does (mechanically)**\n\n- Sets maximum permitted external noise levels for many categories of new motor vehicles and prescribes the laboratory/field test methods used to measure that noise (see Scope and Table 1; methods in Annex A). (1; 28.2.2.1; Annex A)\n- Requires vehicle design and construction (engine and the complete “Noise Reduction System” of components such as exhaust manifold, piping, silencer, and, where essential, air filter) to enable vehicles to meet those limits in normal use and to resist corrosive degradation. (28.2.1.1–28.2.1.2; 28.1.1–28.1.5)\n- Applies to vehicles manufactured on or after the dates listed for each vehicle category in the applicability table; vehicles already complying with ADR 83/00 need not also comply with this ADR. (2.1–2.2)\n- Allows specified international test regimes (UN ECE Regulation 51/01 or 51/02) to be treated as equivalent in certain cases, subject to additional stationary exhaust tests for goods vehicles and omnibuses. (28.3)\n\n**Who this affects**\n\n- Vehicle manufacturers and designers: must design engines and exhaust/noise‑reduction systems so new vehicles meet the dB(A) limits and withstand normal vibration and corrosion (28.2.1). \n- Importers and certifiers: those responsible for type‑approval or certification must run, commission or accept the prescribed noise measurements and test reports (28.2.2; Annex A). \n- Test laboratories and compliance centres: must operate to the measurement methods and equipment standards (Annex A 1.1–1.3) and follow the detailed procedures for moving and stationary tests (Annex A Part 2 and 3). \n- Owners/end‑users only incidentally: the standard regulates vehicles at the point of manufacture/certification; it does not directly create on‑road enforcement procedures in this text.\n\n**Why it matters (claimed purpose and practical effects)**\n\n- The stated function is to limit motor traffic’s contribution to community noise by prescribing design limits and measurement methods (1.1). That claim implies manufacturers will change design choices (exhaust layout, silencer technology, possibly engine calibration) to meet the dB(A) thresholds in Table 1 (28.2.2.2.1 and Table 1).\n\n**Practical mechanisms, costs and incentives**\n\n- Who pays: manufacturers absorb direct design and testing costs. Test labs bear equipment and site costs (Annex A: precision sound level meter, tachometer, calibrated sources, suitable open test site). If manufacturers change component design (silencers, piping), production cost and part‑costs rise; certification delays add administrative costs. (28.2.1; Annex A)\n- What decision‑makers do: conformity is determined by measured values using the specified methods (28.2.2.1; Annex A). Where a vehicle meets an alternative standard recognised here (UN ECE Reg 51/01 or 51/02) that may simplify compliance (28.3). \n- Behaviour likely to change: vehicle design choices (noise reduction system components, exhaust outlet height, engine tuning), and test behaviour (choice of gear and test speed, selection of microphone positions, performing multiple runs) to produce compliant test reports (Annex A 2.3; 3.2; 3.3). \n\n**Trade‑offs, burdens and implementation risk**\n\n- Compliance burden: detailed, technical measurement regime — Type 1 (high precision) meters, calibration before/after runs, specified microphone placement and speeds, multiple repeated runs with acceptance tolerances — creates nontrivial laboratory and track requirements (Annex A 1.1–1.2; 2.3.1–2.3.2; 3.3.4). \n- Precision and repeatability: the standard builds in instrument tolerance adjustments and repeat measurement rules (e.g. subtract 1 dB(A) for instrument imprecision; acceptance criteria for repeated runs) to reduce false failures, but that also increases test complexity (Annex A 2.4.2–2.4.3; 3.4.1–3.4.4). \n- Substitution effects: to meet limits, manufacturers may select heavier or more complex silencers, alter engine maps, or change exhaust outlet geometry (exhaust outlet height is a parameter in Table 1). Those choices affect cost, packaging, fuel consumption or emissions characteristics depending on engineering trade‑offs — the standard does not constrain how compliance is achieved, only the measured outcome (28.2.1; Table 1). \n- Implementation risks: ambiguous or difficult test setups (microphone obstructions, very high outlets, multi‑outlet arrangements) are addressed by detailed positioning rules and fallback clauses, but those permit some discretionary interpretation (Annex A 3.2.9; 3.2.7–3.2.8). Such discretion can create disputes between manufacturers and certifiers about the correct test configuration.\n\n**Efficiency and market effects**\n\n- Competition and entry: the standard imposes a technical compliance cost on all manufacturers selling vehicles in the covered categories and dates; smaller manufacturers or niche producers may face proportionally greater certification costs. \n- Equivalence provisions (28.3) lower duplication where international test regimes are already used, reducing cost for manufacturers who already certified to UN ECE Regulation 51/01 or 51/02. \n\n**Concrete references to notable provisions**\n\n- Scope and affected vehicles: applicability table listing vehicle categories and manufacture‑on‑or‑after dates (2.1). \n- Substitution for ADR 83/00: vehicles complying with ADR 83/00 are exempted from complying with this ADR (2.2). \n- Definitions: “Component”, “Noise Reduction System”, “Net Engine Power (NEP)”, “Diesel Engine”, etc. (28.1). \n- Measurement methods and limits: two measurement methods (vehicle in motion and stationary) specified; results entered in test report; limits in Table 1 (28.2.2.1–28.2.2.2.1; Table 1). \n- Equipment and calibration: high‑precision sound level meter (Type 1); calibration rules and tachometer accuracy (Annex A 1.1–1.3). \n- Test site, microphone placement, vehicle operating procedures and acceptance criteria: detailed procedural rules in Annex A Parts 2–3 (Annex A 2.1–2.4; 3.1–3.4).\n\n(References in parentheses indicate the clause or annex where the rule appears.)"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"The legislation remains focused on its original purpose of limiting external vehicle noise. The 2006 version updates and consolidates earlier versions (repealing previous ADR 28/01 standards) but does not expand beyond noise regulation into unrelated areas. The inclusion of alternative compliance pathways via UN ECE regulations represents harmonization with international standards rather than scope creep."},"complexity_factors":["Extensive cross-referencing to international standards (UN ECE Regulations 15, 24, and 51; EEC Directives 84/424 and 92/97)","47 distinct vehicle subcategories in Table 1 with varying noise limits based on: vehicle category code, engine type (spark ignition vs diesel, direct vs indirect injection), Gross Vehicle Mass (GVM), Net Engine Power (NEP), exhaust outlet height, and on-road vs off-road designation","Nested conditional testing procedures in Annex A with multiple branches: manual vs automatic transmission, number of gears, presence of auxiliary transmissions, power-to-weight ratios, and special provisions for articulated vehicles","Precise technical measurement specifications including: microphone positioning tolerances (+/- 25-50mm), angular requirements (45° or 90° +/- 10°), calibration deviation limits (1dB), and environmental conditions (10dB ambient noise floor)","Mathematical formulas for gear selection (X/2, rounding rules) and engine speed calculations (3/4 ESMP)","Exception handling for unusual cases: special acoustic shielding provisions, obstruction variations, and invalidation criteria for calibration drift","Dual compliance pathways: direct adherence to ADR 28/01 or deemed equivalence through alternative international standards with additional evidence requirements for certain vehicle types"],"plain_english_summary":"This standard sets legal limits on how loud motor vehicles (cars, trucks, buses, motor tricycles made from 1992–93 onward) may be when driving past a microphone and when idling, requiring manufacturers, importers/sellers and test facilities to ensure and verify compliance. It establishes different decibel caps by vehicle type and engine, allows meeting an international ECE test as an alternative, and aims to reduce traffic noise harms to communities."}},"importantCases":[],"_links":{"self":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006","history":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006/history","analysis":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006/analysis","conflicts":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006/conflicts","importantCases":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006/important-cases","documents":"/api/acts/vehicle-standard-australian-design-rule-28-01-external-noise-of-motor-vehicles-2006/documents"}}