Brylee Drive, Conifer Grove - Traffic calming measures Brylee Drive, Conifer Grove - Traffic calming measures

Auckland Transport is proceeding with its plan to install traffic calming measures along Brylee Drive in Conifer Grove. This will involve installation of eight speed humps and a raised pedestrian crossing. We expect these changes to take place later in 2021.


Project status: Under construction from 13 December 2021 to 28 February 2022
Project zone: South (reference number MIP2021-025)


Project overview

As part of resource consent conditions for the neighbouring Waiata Shores development, a link road connection has recently been built joining Brylee Drive to Gosper Road in Waiata Shores. The consent also requires AT to implement traffic calming measures on Brylee Drive before this road is opened.

During November and December 2020, AT consulted with the community. This included a public drop in session about installing speed humps along Brylee Drive, to slow speeds and discourage people taking short cuts once the link is open.

From 11 May to 4 June 2021 we consulted again, including a public drop in session. This was to determine if the speed humps are appropriately positioned and whether the raised pedestrian crossing will improve safety. The majority of respondents told us that the speed humps are positioned appropriately and think that the raised crossing will improve safety.

This project is another step towards our goal of achieving no deaths or serious injuries on our roads. We are guided by the Vision Zero approach to transport safety, which prioritises human safety over other measures (like minor time saving).

Design


Download the Brylee Drive Traffic Calming Public Feedback (PDF 812KB, 25 pages)

Community feedback from December 2020

Below is a summary of public feedback and our responses from the December 2020 consultation.

Speed humps

  • Requests for no speed humps on Brylee Drive and that traffic calming is not required.
    In order to slow driver speeds and reduce the number of vehicles that travel on this road, we are proposing to install speed humps along the full length of Brylee Drive. These changes aim to improve road safety once the link road between Brylee Drive and Gosper Road is opened by slowing driver speeds. It also aims to discourage potential rat-running.
    The proposed speed calming devices on Brylee Drive are required as a resource consent condition as part of the neighbouring Waiata Shores development. A link road connection has recently been built joining Brylee Drive to Gosper Road in Waiata Shores. The consent requires Auckland Transport to implement traffic calming measures on Brylee Drive before this road is opened.
  • Suggestion for speeds humps on the link road between Waiata Shores and Conifer Grove.
    The granted resource consent requires Auckland Transport to implement traffic calming measures along the length of Brylee Drive. Following implementation, we will also monitor the directly adjoining roads, including the new link road.
  • Request for no speed humps between Keywella Drive and roundabout.
    To effectively reduce driver speeds along Brylee Drive, the speed calming devices will need to be placed at consistent intervals. Details are currently being confirmed in the design stage, however there will likely be 8-10 speed humps along the length of Brylee Drive in order to achieve the desired operating speed.
  • Requests that speed humps are not placed near any intersection with side streets, so vehicles are not turning on to a speed hump.
    We will ensure speed humps are not immediately adjacent to intersections. Instead, it is preferred to place the speed humps near (but not directly by) the intersection to effectively slow down vehicles on approach on Brylee Drive. This will provide more opportunities and gaps for vehicles on the side roads to safely exit onto Brylee Drive.
  • Request for 8 – 10 speed humps to deter speeding.
    This has been taken into consideration. Details are currently being confirmed in the design stage and there will likely be 8-10 speed humps along the length of Brylee Drive in order to achieve the desired operating speed.
  • Concern that no measurements or dimensions showing gradients of any proposed traffic calming measures.
    A typical speed hump, that goes across the full width of the carriageway, is 3.7m long and 0.1m high.
  • Request for provisions for minimum disruption to cycling.
    One of the benefits of speed humps over other types of calming devices is that their profile allows for comfortable cycling while still calming driving speeds effectively.

Speed calming

  • Concern that residents were previously advised at the Council hearings that speed calming measures were to be implemented on other roads (Beaumaris, Walter Strevens, Kindergarten Dr, Bunnings Street etc.). Request for more information about speed calming being extended further than Brylee Drive.
    The consent requirement is that only Brylee Drive is to be traffic calmed. We will, however, monitor the surrounding roads to determine if there is any increase in travel speeds or rat-running once the Brylee Drive traffic calming has been installed.
  • Suggestion to use similar methods to supermarket car parks to slow traffic.
    Judder Bars as are used in the likes of supermarket car parks, are only used for private carparks or private areas as they are not suitable for public roads for a number of reasons, namely their steep profile and reduced durability.

Pedestrian crossing

  • Request for a raised pedestrian crossing at the entry to Brylee Drive. Connection to the new Shared Path along the motorway is being installed beside the Walter Strevens Bridge and the number of pedestrians crossing this section of Brylee Drive will increase dramatically.
    We are currently considering this request now that we are in our design stage.
  • Requests for raised pedestrian crossings along Brylee Drive. Concern for the safety of children in the area.
    The speed humps are expected to calm the full length of the road so that operating speeds are low enough to allow people to cross safely at any point along the route. We are also considering a raised pedestrian crossing near the Walter Stevens roundabout.

Speed tables

  • Requests for speed tables, not speed humps. Suggestion that speed tables are better for car suspensions, slow traffic more significantly, not as many needed and are a safer option.
    It is considered better to calm the full length of the road so that the general speed environment is low enough to allow for pedestrians to cross safely at any point along the route.
    From other recent AT projects, it has been demonstrated that bus routes with speed humps generated fewer noise/vibration issues than those with speed tables. Also, qualitative ratings of passenger comfort were higher on the route with speed humps compared to the one with speed tables. In addition, there seemed to be no difference between the impact of speed tables vs. speed humps on bus passenger numbers and travel time.
    Speed tables cover a longer length of road compared to speed humps. On residential roads such as Brylee Drive, the significant number of residential driveways potentially means that device spacing would undermine the ability to achieve the desirable operating speeds. They would also result in the loss of on-street parking.

Link Road

  • Concerns over the link road connection, including concern that Brylee Drive will be used as a rat run and that it will impact the quiet residential nature of the area.
    The Link Road connection has been granted as part of the Waiata Shore development and is nearing completion. The connection will allow for a future bus service, better network, local connectivity, and greater resilience in the traffic network.
    The speed calming devices are also required by the consent conditions of the Waiata Shore development. They are required to slow driver speeds and reduce potential rat-runs on this road.

Further requests

  • Request for stop signs at the intersection of Keywella Drive and Brylee Drive.
    We will review the intersection control based on the post-construction operating speed to determine if any change of control is required.
  • Request for stop sign at the intersection of Brylee Drive and Gosper Road.
    Brylee Drive to Gosper Road is a through road that doesn’t require a stop control. However, we will consider the suggested location of speed humps to ensure overall speed is reduced ahead of the Gosper/Brylee connection.
  • Request for chicanes.
    Chicanes or similar were considered but are not preferred as they are less effective at deterring non-local through traffic and reducing speeds.
    As Brylee Drive is a future bus route, horizontal treatments such as chicanes will need to be designed to cater for bus tracking. This means it would have little impact on smaller vehicles as they would be able to negotiate through the chicanes easily, especially as the road is already wide. It would not be effective in terms of deterring non-local through traffic.
    Chicanes or other horizontal treatments also cover a longer length of road compared to speed humps. On residential roads such as Brylee Drive, the significant number of residential driveways potentially means that device spacing would exceed 120m, therefore undermining the ability to achieve the desirable operating speed.
    Removal of on-street parking spaces would also be required for the chicane or other horizontal treatments.
  • Concern for the safety of children with increased traffic past the playground/park in Gosper Road. Cars park illegally along the kerb and children are hidden from view - they can run out into traffic from between parked vehicles.
    We will pass this information about illegal parking in this area to our Parking Team to enforce.
  • Request for broken yellow lines at the intersection of Keywella Drive and Brylee Drive.
    We have visited the area concerned and assessed the feasibility of installing broken yellow lines. Several factors are carefully considered when assessing a parking restriction including the road width and topography, traffic flow, residents’ off-street parking and availability of neighbouring on-street parking spaces, visibility concerns, other safety concerns and crash statistics.
    It is important we undertake this type of assessment so parking restrictions are only implemented where a significant safety or accessibility issue has been identified, and in streets that are classified as narrow roads.
    Our investigation shows no crashes in the last five years in the vicinity of the subject intersection and the parking demand is reasonably low.
    After considering all factors of our assessment we regret to advise you that we are unable to proceed with your request for a broken yellow line restriction.
  • Suggestion that the roundabout will need to be changed to a signalised intersection due to the increase in traffic.
    The proposed speed calming devices are to deter rat-running movements via Brylee Drive hence minimise the increase in traffic through the roundabout and Brylee Drive. We will monitor the roundabout closely for any capacity issues.
  • Requests to ban trucks on the road. Concern that trucks will use Brylee Drive, rather than Great South Road to access the new Countdown.
    The proposed speed calming devices are to deter cars and trucks rat-running via Brylee Drive. It is important to have enough calming devices on Brylee Drive to effectively discourage trucks from using Brylee Drive.

Other issues

  • Request for AT to be transparent with the cost of implementing these measures.
    Cost estimates will be produced during the design stage.
  • Request for speed cameras.
    Speed Camera locations are identified by NZ Police. Cameras are placed where there’s problems with excessive speed, and/or research that shows a history of crashes causing death and/or serious injury.
    Brylee Drive would unlikely meet the criteria as the current average speed on Brylee Drive is approximately 51km/hr, and this is expected to be reduced as a result of the speed calming devices.
    However, should you notice common trends, such as speeding during certain times of the day or individual vehicles, you may also want to contact the police with further details so they can carry out targeted enforcement.
    View the link to the police website for information about how sites are selected and where the cameras are being sited, can be found here.
  • Concern about the potential for stormwater to accumulate in heavy rainfall at the northern end of Brylee Drive Conifer Grove.
    Stormwater will be looked into as part of the detailed design stage, to ensure the proposed calming devices would not hinder any stormwater issues.
  • Concerns that it is difficult to exit the side streets on to Brylee Drive.
    The proposed speed calming devices are expected to reduce travel speed on Brylee Drive, which in turn would create gaps/opportunities for drivers to exit the side roads more safely.
  • Concern about the impact on Brylee Drive in a few years if Manuroa Road and others are closed off, and all traffic will be fed through Taka Street and across to Walter Strevens Drive.
    We will pass this to the appropriate project team to look into the potential impact.

Drop-in session

  • Concern that the drop-in session was held while most people were at work. Requests for an evening or Saturday public meeting.
    We appreciate that the drop-in session time did not suit everyone. It was however well attended by the local community. We offered the drop-in session in addition to providing information via letter and web page information. We also provided a contact number and email address for residents to contact us to discuss their feedback or any issues or concerns they may have. We will look to hold a public meeting as part of the consultation that we will be running on the new proposed design for traffic calming on Brylee Drive.

Why speed humps are the preferred option

We have explored a range of traffic calming measures that would be suitable for Brylee Drive, these included speed humps, speed tables, Swedish-style raised tables, roundabouts, speed cushions and chicanes.

See Other traffic calming measures for details on these devices.

Render of a speed hump on a street.
Figure 1. Example of a speed hump.

We identified speed humps (see Figure 1) as the most suitable option for this location for the following reasons:

  • Performance and feasibility: speed humps are very effective in reducing driver speeds. Data from previous projects have demonstrated that speed humps generate fewer noise and vibration issues than speed tables. Due to the short length and the profile of speed humps, it also means vehicles can park on them so no on-street parking is removed.
  • Safety and accessibility: the speed humps are expected to calm the full length of the road so that driver speed is lowered enough to allow people to cross safely at any point along the route. The profile of the speed humps is also more comfortable for people cycling.
  • Cost-effectiveness and deliverability: speed humps are the most cost-effective option to achieve slower speeds. While speed reduction impact is similar to other measures, speed humps require less materials and less construction time compared to other alternatives. It will also result in lower maintenance and whole of life costs while still enabling effective traffic calming.
  • Public Transport: Brylee Drive is intended to become a low frequency bus route. The use of speed humps in other recently completed projects has shown that there were minimal and/or acceptable impacts in terms of bus passenger numbers, user experience, travel time, noise/vibration from the devices, and overall speed reduction.

Other traffic calming measures

We explored a range of traffic calming measures that would be suitable for Brylee Drive and the following were the other options considered:

Vertical treatments

Speed tables

A speed table is a raised table (a speed hump that is flat and wide) that aims to slow vehicles to a safe speed. Speed tables are typically considered where pedestrian crossing demand is expected. However, for Brylee Drive, high pedestrian crossing demand is not anticipated given that it is a residential area. It is considered better to calm the full length of the road so that the general speed environment is low enough to allow for pedestrians to cross safely at any point along the route.

From other recent AT projects, it has been demonstrated that bus routes with speed humps generated fewer noise/vibration issues than those with speed tables. Also, qualitative ratings of passenger comfort were higher on the route with speed humps compared to the one with speed tables. In addition, there seemed to be no difference between the impact of speed tables vs. humps on bus passenger numbers and travel time.

Swedish-style raised tables

Swedish speed tables are a raised table with only one sharp ramp and a more gentle exit which gives a smoother ride for vehicles and passengers.

Swedish tables are typically considered where there are large numbers of heavy vehicles and high frequency / double decker buses are expected. For a residential street like Brylee Drive, heavy vehicle numbers are expected to be low. Having heavy vehicle friendly devices would not be likely to deter heavy vehicles from using Brylee Drive as a rat-run.

Swedish tables cover a longer length of road compared to speed humps. On residential roads such as Brylee Drive, the significant number of residential driveways potentially means that device spacing would exceed 120m, therefore undermining the ability to achieve the desirable operating speed.

Swedish tables also cover a wider width and a central traffic island is required to separate the different slope profiles on each direction. This will result in the loss of on-street parking in order to fit the Swedish tables.

Roundabout controls at intersections

Roundabout controls were considered at various intersections, complemented with vertical treatments at mid-block locations. This however is considered less effective than having all vertical treatments, due to the need to cater for buses turning at the roundabouts. Due to the boundaries of the nearby properties there may also be issues creating enough space for buses to safely navigate the roundabout.

Speed cushions

Speed cushions are a series of a small speed humps that allow vehicles with larger wheel track to straddle the cushion, while vehicles with a smaller wheel track must drive over the edges of the cushion.

Speed cushions are not effective in reliably slowing vehicles, especially SUVs, on their own. It was determined that speed cushions will not result in the necessary slowing of speeds.

Horizontal treatments

Chicanes, pinch points or similar

Chicanes or similar were considered but are not preferred as they are less effective than the above vertical treatments at deterring non-local through traffic and reducing speeds. Vertical treatments are preferred from a safe system perspective.

As Brylee Drive is a future bus route, horizontal treatments such as chicanes will need to be designed to cater for bus tracking. This means it would have little impact on smaller vehicles as they would be able to negotiate through the chicanes easily, especially as the road is already wide. It would not be effective in terms of deterring non-local through traffic.

Chicanes or other horizontal treatments also cover a longer length of road compared to speed humps. On residential roads such as Brylee Drive, the significant number of residential driveways potentially means that device spacing would exceed 120m, therefore undermining the ability to achieve the desirable operating speed.

Removal of on-street parking spaces would also be required for the chicane or other horizontal treatments.


For more information on this project

Contact Auckland Transport