Application

General configuration

In general, when using audio tactile profiled (ATP) roadmarkings, practitioners should:

• use ATP for edgelines, and may use ATP for lane lines and centre-lines if beneficial;  
• apply them continuously along a route, except as noted; and
• consider all road users and function of the road before application.

Configuration and dimensions

• ATP profiled ribs do not replace normal continuous edgelines but supplement them.
• The profiled ribs should normally be placed alongside, overlapping or on top of the flat or structured line markings. Where ATP is overlapping or on top, the ribs should protrude at least 25mm but preferably 50mm beyond the marking so as to be clearly visible to users of two-wheeled vehicles.
• The width of the lane between profile markings should not be less than 3.35m (a low number of heavy commercial vehicles might permit a narrower lane).
• ATP edgeline markings should be installed continuously across minor access-ways, unless there is an issue with gravel being trafficked onto the seal but discontinued at least 20m clear of major access-ways and intersections and their diverge and merge areas.
• A gap of 20m should be left in ATP edgelines wherever cyclists are expected to cross the edgeline. Examples include bridge approaches, intersections with cycle trails, and pinch points where the shoulder is too narrow for a short distance. A longer gap may be needed where cyclists have poor forward visibility of a pinch point.
• ATP lines should taper at a rate no steeper than 1:100; ie a 100mm lateral shift takes at least 10m.

ATP roadmarkings should conform to the dimensions described in Table 2‑29. Information relating to their use in specific situations can be found in the following sections:

• Centre-lines
• No-passing lines
• Edgelines
• Lane lines

Table 2‑29: Configuration of ATP markings

Table 2‑29 note:

1. Where the width of the roadway is not adequate to accommodate markings of this size, the width of the marking may be reduced to 150mm for white centre-lines and 100mm for no-passing lines.

Cyclists

Where there is an adequate road shoulder, ATP edgelines improve cyclist safety by deterring motor vehicles from inadvertently crossing the edgeline. While cyclists can retain control while crossing ATP markings, they are uncomfortable to ride over, and cyclists will generally ride to avoid them; this needs to be taken into consideration when determining the positioning of ATP markings. Where ATP is being installed in locations that may alter where cyclists ride, an assessment of the impact on cyclists should be undertaken. This needs to consider cycle numbers, light and heavy traffic volumes, and alternative or complementary safety interventions.

Points to consider:

• shoulder widths clear of ATP edgelines should be a minimum of 1.0m to provide for cyclists 
  see Section 4.11 of the New Zealand Cycle Trail Design Guide(external link);
• in constrained situations a 600mm clear shoulder width may be acceptable;
• clear shoulder widths between 300mm and 600mm should be avoided, however, where such situations exist, consider:
  • increasing the seal width to provide a minimum 600mm clear shoulder width, desirable 1.0m;
  • reducing the width of the traffic lane to provide a minimum 600mm clear shoulder width (configuration and dimensions for minimum lane width)
    Configuration and dimensions;
  • increasing the width of the traffic lane to reduce the shoulder width and placing the ATP near the edge of seal, adjacent to or overlapping the edgeline; and
  • installing ATP on the traffic side of the line, as a final resort, if the above three options are cost impractical and lane widths are greater than 3.5m. This exception should be carefully considered based on the location and function of the road and advice sought from Waka Kotahi NZ Transport Agency (for state highways the approval of the Lead Safety Advisor (Roads and Roadsides) is required); and
• where clear shoulder widths are less than 300mm, ATP should be placed to the left of or overlapping the edgeline, and consideration should be given to moving the edgeline to the left to increase the available lane width;
• on very narrow roads without shoulders, but where ATP edgelines would provide safety benefits, they may be placed hard against the edge of seal overlapping the edgeline;
• cyclists require extra space on both uphill and downhill grades, especially over 5%. In these locations where a shoulder is provided, it may need to be wider. On downhill sections, because the speed differential between cyclists and motor vehicles is reduced, cyclists may also be accommodated in a wider lane. As a guide, a cyclist is likely to need a minimum clear width of 600mm to ride downhill in a shoulder; and
• where cyclists are required to ride in the lane, ATP should not be installed where Safe Stopping Distance is not available, based on a cyclist having a 1.1m object height.

For further guidance on the decision-making process for the application of ATP edgeline markings when considering cyclists, refer to Figure 2‑15.

Figure 2‑15

For sections of road where high volumes of cyclists are expected, local cycling interest groups should be consulted to confirm that the ATP installation does not adversely affect cyclists’ use of the road.

Noise

• The noise generated by ATP roadmarkings may cause disturbance to people in residential areas and other noise sensitive land uses located close to the road.
• ATP should not be installed along lengths of road where the associated noise will cause disturbance to noise sensitive land uses in the vicinity.
• Where noise nuisance precludes use of ATP, or if complaints arise, consideration should be given to using an alternative treatment such as wider sealed shoulders, wider edgelines or centre-lines and the use of structured markings.

Installation, maintenance and removal

• Refer to Specifications M24 and P30 and their notes for full details of materials, profile designs, retroreflectivity, skid resistance and performance requirements.

Specification M24: audio tactile profiled roadmarkings

Specification P30: high performance roadmarking

• For performance purposes, there should be no more than 10 missing ribs of profile marking in sequence or a maximum permitted loss of 5% within each kilometre of marking.
• Special care is required if an ATP roadmarking is removed or the road to which it is applied is in need of maintenance.
• When resealing, a subjective assessment of the remaining effectiveness should be undertaken. The reinstatement should be either through remarking with ATP or if sufficient profile remains, remarking a long-life marking over the ATP.