Document ID: chunk:federal_register_of_legislation:F2025C00107:reg:4:p16
Version: federal_register_of_legislation:F2025C00107
Segment Type: reg
Provision Reference: reg 4 (pt 16/26)
Character Range: 130159–133169

end gate, while the driver attempts to keep all of the wheels of the vehicle within the lane.
 1.                            Reference Speed tests
The vehicle must be subjected to a series of J-Turn tests to determine the Reference Speed for each steering direction.  The Reference Speed is used in the Engine Torque Reduction Tests, and the Directional Control and Roll‑over Control Tests.
 1.                     Preliminary Reference Speed determination
     1.                 The vehicle must be subjected to two series of tests using the 'J-Turn Test Course' at increasing 'Entrance Speeds'.  One series must be conducted using clockwise steering, and the other series anti‑clockwise steering.
     2.                 During each test, the driver attempts to maintain the selected 'Entrance Speed' throughout the 'J-Turn Test Course'.
     3.                 The required 'Entrance Speed' (± 2 km/h) for the first test of each series may be determined by the 'Manufacturer', using the expression:

where:
V1 = the 'Entrance Speed' (in km/h) for the first test in a series;
       a = the minimum 'Lateral Acceleration' (in m/s2) at which the 'Manufacturer' anticipates, 'Vehicle Stability Function Service Brake Application' may occur (not to exceed 3.89 m/s2); and
       R = the fixed radius (in metres) of the 'J-Turn Test Course' (measured from the centre of the lane) selected by the 'Manufacturer'.
Otherwise (i.e. where not determined as per the above expression by the 'Manufacturer'), the 'Entrance Speed' for the first test in each series must be 32 km/h ± 2 km/h.
 1.                 The 'Entrance Speed' shall be incrementally increased by up to 2 km/h for each subsequent test until 'Vehicle Stability Function Service Brake Application' occurs or any of the wheels of the power driven vehicle depart the lane.  The 'Entrance Speed' at which 'Vehicle Stability Function Service Brake Application' occurs is the Preliminary Reference Speed.
 2.                 The Preliminary Reference Speed must be determined for each direction: Clockwise steering and anti-clockwise steering.  During any test, if any of the wheels of the power driven vehicle depart the lane at any point within the first 120 degrees of radius arc angle, the test shall be repeated at the same 'Entrance Speed'.  If any of the wheels of the power driven vehicle depart the lane again, then four consecutive tests shall be repeated at the same 'Entrance Speed' less 1 km/h.
 1.                     Reference Speed determination
     1.                 Two series of tests must be performed using the 'J-Turn Test Course', at the Preliminary Reference Speed (±2 km/h) determined in clause 6.1.1 above, to determine the Reference Speed.  One series shall consist of up to four consecutive tests performed using anti-clockwise steering.  The other series shall consist of up to four consecutive tests performed using clockwise steering.
     2.                 During each test, the driver attempts to maintain a speed equal