2411-43615 SRA - Approved Document

Treatment options to improve safety of pedestrians, bicycle riders and other path users at driveways
Document approved for purposes relating
to condition 2 of referral agency response:
2411-43615 SRA
3.2.2    Sight distance requirements at driveways

Figure 3.2.2 shows the visibility triangle that should be provided around driveways to protect path
users. This assumes vehicles are perpendicular to the path, which provides optimal sight
lines (maximum observation angle is 120°). The figure includes ‘x’ and ‘y’ dimensions as follows:

    •    The ‘x’ dimension is measured from path user location into / towards the property. The
         ‘x’ dimension should allow drivers in forward exiting vehicles to sight path users before their
         vehicle encroaches the path or in time to stop to avoid a crash. Where path users can see at
         least 250 mm of vehicles, it also allows them to observe vehicles exiting or preparing to exit. In
         the case of reversing vehicles, it can allow path users to see activated taillights in time to stop.
         Where vehicles on driveways are not pausing to give way to path users, it is desirable to
         use SSD for motor vehicles as the ‘x’ value. See Section 3.2.4 for SSD guidance for motor
         vehicles at driveways. Where speeds are tightly controlled (see Section 3.3), ‘x’ values can
         generally be assumed from Table 3.2.2.

    •    The ‘y’ dimension reflects SSD for the path users. To achieve desirable outcomes, path users
         are assumed to be travelling at a comfortable speed for the type of facility. These are reflected
         in the ‘desirable’ values provided in Table 3.2.2. Further information relating to SSD for path
         users and derivations of values are provided in Table 3.2.2.

Figure 3.2.2 – Sight lines for path users based on bicycle stopping distances




Note:
    •    ‘X’ values normally measured to edge of path. On paths wider than 2 m, it may be appropriate to assume
         path users occupy the left side of the path, and measure from the centre of the path. At a complete stop,
         a distance of 2.5 m for forward exiting or 3 m for reversing drivers provides visibility to path users.
    •    ‘Y’ values should be measured from the worst-case scenario driver position. It is usually assumed the
         vehicle is 0.5 m–1.5 m from the left of the lane / driveway when exiting. For reversing vehicles, sight
         lines are taken from middle of vehicle if the driver is looking over left shoulder and 0.5 m from the edge
         of vehicle, when looking over right shoulder.
    •    Where driveways are frequently used by heavy vehicles, larger ‘x’ and ‘y’ values are required. Absolute
         minimum ‘x’ values are considered to be 5 m combined with ‘desirable’ ‘y’ values. Consideration should
         also be given to heavy vehicle blind spots as per Section 3.2.5.
    •    Sight lines from vehicles will be further obstructed by vehicle framework and furniture (see Austroads
         Guide to Road Design Part 4A Commentary 1).




Guideline, Transport and Main Roads, February 2021                                                                16