Uncontrolled and priority controlled intersections

Description

An uncontrolled intersection is generally used where low vehicle volume roads meet in a T intersection; no control is implemented and normal give way rules apply.  A priority control is generally used for intersections as vehicle volumes increase.  At priority intersections, the side road(s) has either a ‘Give Way’ or a ‘Stop’ control sign. 

Priority and uncontrolled intersections are the most common intersections in the transport network in New Zealand. Pedestrians must give way when crossing at priority and uncontrolled intersections when there is no formal pedestrian crossing, eg. zebra crossing. The figures below are examples of uncontrolled and priority intersections.

Uncontrolled intersection. (Source: Canterbury Maps)

Priority intersection (STOP). (Source: Canterbury Maps)

Contextual considerations

Uncontrolled and priority intersections have the following benefits and implications for pedestrians crossing.

Benefits

• Minimal delay for more able and more confident pedestrians to cross when there are low vehicle Note: Some pedestrians will find it difficult to cross at this type of intersection unless priority crossings are provided.

Implications

• The presence of conflicting and turning vehicle movements can make crossing decisions more complex for pedestrians. For example, four way stop intersections are generally more difficult for pedestrians to cross.
• The uncontrolled approaches are likely to have faster vehicle speeds and therefore can be more difficult and less safe for pedestrians to cross.
• Providing corner radii that accommodate large turning vehicles increases crossing distances for pedestrians and turning speeds of smaller vehicles. For more information refer to Corner radii section.
• Higher vehicle volumes are more difficult for pedestrians to find a suitable gap to cross as described further below.

When vehicle volumes are above about 750 vehicles in the peak hour on the major road (approximately 7,500 vehicles per day) it becomes increasingly difficult for pedestrians to find a suitable gap to cross, and therefore their waiting delay becomes unsatisfactory. Therefore, pedestrian median islands are recommended where pedestrians need to cross a major road with vehicle volume of more than about 750 vehicles per hour (7,500 vehicles per day). Low vehicle volume environments (less than 750 vehicles in the peak hour) should have kerb extensions to minimise the crossing distances for pedestrians.

PNG: Crossing aids and pedestrian delay

Recommended parameters

• Provide traffic calming and physical crossing aids to minimise crossing distances, reduce vehicle speeds and assist pedestrians to cross. This could include kerb extensions, pedestrian/median refuges, and/or raised platforms.
• Provide sufficient space for pedestrians to wait on the footpath out of the pedestrian through route.
• Primary Safe System treatment if operating speeds are below 30km/h.^[1]

Legal considerations

The kerb and channel of any footpath must permit the safe and easy passage from kerb to kerb of any mechanical conveyance normally and lawfully used by a disabled person.(external link) 

NZ Local Government Act 1974, s331(2)(external link) 

Pedestrians crossing at uncontrolled or priority intersections are required to give way to vehicles unless there is a zebra crossing present, according to current NZ Road Code.

Design considerations

Besides the general intersection design principles, the key considerations to provide safe and convenient pedestrian movements at uncontrolled and priority intersections are:

• Align crossing points to pedestrian desire lines (refer to red lines on photo below).
• Minimise the pedestrian crossing distance. This can be achieved through kerb extensions and/or pedestrian refuges.
• Minimise the complexity of the crossing task for pedestrians. For example, median refuges allow pedestrians to cross the street in one vehicle direction at a time.
• Where pedestrian volumes are significant at uncontrolled/priority intersections, for example in town or activity centres or public transport stops/stations, consider whether priority should be given to pedestrians through the installation of zebra crossings on one or more approaches.
• Provide adequate storage space on footpaths and refuges to accommodate people waiting to cross out of the footpath through route. This requires consideration of pedestrian activity and pedestrian crossing delays due to vehicle
• Ensure adequate visibility between pedestrians and other road users. No stopping / parking restrictions and vertical deflection devices such as pedestrian platforms and raised intersections can assist as they improve the visibility of pedestrians and they also reduce vehicle speeds through the intersection.
• Ensure lighting of the crossing points is adequate.
• Provide kerb ramps and other intersection cues (including tactile indicators) and ensure these are located appropriately.

PNG: Intersection design principles

PNG: Vertical deflection devices

PNG: Street lighting at crossings

PNG: Kerb ramp locations

PNG: Designing for blind and low vision people

Priority intersection with footpaths and kerb crossings on pedestrian desire lines. (Source: Canterbury Maps)

Refer to Design elements section below for more detailed guidance on specific treatments. 

Design elements

Specific treatments can assist pedestrians to cross at uncontrolled and priority controlled intersections or give them priority to cross. The combination of infrastructure depends on the context of the intersection.  Further detail and examples for each treatment are provided below.

Kerb extensions

The shape and layout of kerb extensions will usually reduce crossing distances for pedestrians. The shape of the kerb extensions will depend on the size of turning vehicles using the intersection. Ideally the kerb ramps should be placed on straight sections of the kerb extension for ease of applying tactile indicators that are legible.

PNG: Kerb extensions

Pedestrian refuge islands

Pedestrian refuge islands can assist pedestrians to cross at an intersection as they make the crossing task easier. However, they can result in crossings being located off pedestrians’ natural desire lines particularly if space is required for right turning vehicle movements as shown in the example figure below. Pedestrian refuge islands are usually required if the vehicle volumes on the major road exceed about 750 vehicles per hour (approximately 7,500 vehicles per day).

PNG: Crossing selection process

PNG: Pedestrian / median refuges

Layout showing how providing a refuge island can move pedestrians off their desire line indicated by the red arrows. (Source: Ward et al 2020)

Pedestrian platform across side road

A raised platform or raised table can be installed across a side road incorporating a place for pedestrians to cross the side road. Although in NZ the road rules still afford drivers the priority (pedestrians must give way), the platform serves to reduce vehicle speeds, and provides a more comfortable crossing for pedestrians as they do not have to negotiate kerb ramps down onto the roadway, then back onto the footpath. As pedestrian platforms do not give pedestrians priority, they can be unsuitable for some pedestrians. These treatments can operate as courtesy crossings if the vehicle speeds are low and the street context means drivers are likely to give way to pedestrians waiting to cross.

PNG: Courtesy crossings

An example of a pedestrian platform across a side road is shown in the photo below. Note, the platform colour is distinct from the footpath to make it clear that pedestrians do not have priority.

Pedestrian platform across a side road, Nelson (Photo: Mark Edwards)

Pedestrian platforms are most appropriate where pedestrian volumes are higher than turning vehicle demand, and vehicle demand is modest.

Pedestrian platforms often include kerb extensions to narrow the throat of the intersection thereby reducing the crossing distance for pedestrians and to encourage slower vehicle speeds. The pedestrian platform should be located to meet the pedestrian desire line across the side road.

It is important that pedestrians do not falsely perceive the treatment as a continuation of the footpath. To avoid this misunderstanding:

• the material on top of the treatment should be significantly different in colour and/or texture from the footpath
• there should be a clear demarcation between the roadway and the footpath.

The table below describes the design elements for pedestrian platforms at side roads.

Table: Design elements for pedestrian platforms across a side road

A typical layout of a pedestrian platform across a side road, with a refuge island, including the appropriate signs and markings arrangement is shown in Figure 13-1 of the TCD Manual Part 4 (draft for consultation)

Raised intersections

Vertical deflection can be applied to an entire intersection. This is known as a raised intersection. Raised intersections can slow vehicle speeds and increase driver awareness of the intersection (eg through different surfacing) however they do not provide priority to pedestrians and are therefore not suitable for some pedestrians and in some contexts. Higher vehicle flows can make it difficult for pedestrians to find a suitable gap in which to cross. In these situations, the inclusion of pedestrian crossing and/or crossing aids (eg pedestrian refuges) in addition to the raised intersection is recommended as shown in the second figure below.

Recommended layout for low vehicle volumes on major road. (Source: Ward et al 2020)

Recommended layout for medium to high vehicle volumes on major road. (Source: Ward et al 2020)

The signs and markings for raised uncontrolled or priority controlled intersections are provided in Section 13.4 of the TCD Manual Part 4 which also includes a typical layout in Figure 13-2. Note this layout does not show the pedestrian crossing aids such as tactile indicators that should be provided. It is important to ensure that pedestrians with low vision do not inadvertently enter the intersection through the use of tactile indicators or other detectable means. Depending on the context and pedestrian demand there also may be a need for other crossing aids such as pedestrian refuges and kerb extensions to be provided at the raised intersection.

TCD Manual Part 4 (draft for consultation)

Zebra crossings

Zebra crossings may be provided near uncontrolled and priority controlled intersections to assist pedestrians to cross. These can be particularly useful where pedestrian volumes are higher, for example in town and activity centres. It is recommended these are raised zebra crossings or they are placed on a raised intersection to ensure the vehicle speeds are low (<30km/h) which ensures they are Safe System aligned.

A zebra crossing close to an intersection means a driver may be focusing on the intersection rather than the crossing. Therefore, it is important to ensure that visibility to and through the intersection for drivers and pedestrians is adequate. In addition, slower vehicle speeds give drivers more time to react and safely stop to avoid a collision.

Zebra crossings at a raised priority intersection, Tauranga. (Photo: Matthew Noon)
Note: small paving blocks may make detecting the tactile paving more difficult for people who are blind or have low vision.

The guidance on when to use a zebra crossing and the location considerations in the Crossings section are also applicable for those near intersections.

PNG: Zebra crossings

Also, Section 4.10 of the TCD Manual Part 4 lists some matters that should be considered regarding the placement of zebra crossings near intersections and the traffic control device requirements.

TCD Manual Part 4 (draft for consultation)