14. Light Units - Alignment

14.1 General – Light Units

14.1.1  Light units must be 200 mm or 300 mm Light Emitting Diode (LED) signal module type and as specified in Appendix A. 

14.1.2  Sets of light units of warning systems must flash alternately and uniformly at a rate of 45 to 65 flashes per minute.

14.2 Alignment Height – Front and Back Lights for Vehicles

14.2.1  Light units must be aligned so that the axes of the light units pass through a point 1.6 m above the road surface at stopping sight distance.

14.3 Alignment Distance – Front Light Units for Vehicles

14.3.1 Front light units must be aligned through the centre of the approaching traffic lane for which they are intended as follows:

  1. at a minimum to the stopping sight distance; or
  2. at the point at which the light units are first visible, if this point is less than the distance specified in (a).

14.4 Alignment – Intermediate Front Light Units for Vehicles

14.4.1  Additional sets of light units must be aligned to cover any intermediate areas of the road approaches between the coverage provided by the front light units aligned as required in article 14.3 and the back lights aligned as required in article 14.5.

14.4.2  Additional sets of light units provided for crossing user must be aligned through the point that is 1.6 m above ths surface of the road at the point at which the crossing user enters the road approach.

14.5 Alignment – Back Light Units for Vehicles

14.5.1  Back light units intended for motor vehicles approaching the grade crossing from a lane on the opposite side of the line of railway from the warning signal on which they are installed, must be aligned through the centre of that lane, 15 m in advance of the warning signal for that side of the line of railway.

14.6 Alignment – Light Units Installed Exclusively for Sidewalks, Paths or Trails

14.6.1  Light units installed exclusively for sidewalks, paths, or trails, must be aligned to be visible through a point 1.6 m above the centre of the sidewalk, path or trail and 30 m (100 ft) in advance of the nearest rail on both sides of the line of railway or the point at which the set of lights units first become visible if less than 30 m (100 ft).

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