Christchurch - Rapanui – Shag Rock Cycleway | Puari ki Rapanui
The Rapanui – Shag Rock Cycleway is one of Christchurch City’s 13 major cycleways. The first section of the Rapanui Cycleway opened in December 2017 and the first 2 km of the route, from Fitzgerald Avenue to Aldwins Road, is a neighbourhood greenway. This links to Linwood Park and beyond.
The rationale for choosing the route was to avoid adjacent arterial roads that are busy. The chosen route had volumes of less than 2,000 veh/day on all links (except for Worcester Street, which averaged 3,000-4,000 veh/day beforehand) but many of the streets had a wide cross-section (about 14 m) that required much traffic calming to reduce the speed environment.
The scope of this case study is the neighbourhood greenway section of the route, where a good cycling environment is created on local roads through speed and volume control measures.
For a greenway to be successful, vehicle volumes should ideally not exceed 2000 vehicles a day. To help achieve this, particularly along Worcester St, the signalised intersection at Fitzgerald Ave was closed to east-west through traffic and a diagonal diverter closure was planned at the England / Worcester intersection. Intersection treatments along England Street also restricted traffic on this route to left-in / left-out movements only.
In a successful greenway, speeds should not exceed 30 km/h – this low operating speed can be difficult to design for in a grid network with long straight roads. As well as intersection treatments described elsewhere, mid-block narrowing points with raised humps (typically 60-70 m apart) were used to slow down traffic speeds. The posted speed limit was also reduced to 30 km/h.
Some residents and commercial operators are opposed to measures that slow or reduce traffic as they perceive this to be an inconvenience; a proposed diagonal closure at the England / Worcester intersection did not proceed due to concerns about the impacts on businesses further east (despite the presence of a grid network of streets).
Traffic calming measures resulted in some localised parking loss, which was opposed by some parties.
A grid road network such as that surrounding the Rapanui – Shag Rock cycleway is the most ideal street form to introduce a neighbourhood greenway, as motor traffic can be encouraged to use adjacent parallel streets. In this case, the busier collector routes Gloucester and Hereford Streets lie only 120 m to the north and south of the greenway along Worcester Street.
Conversely, a grid network also means that the greenway route is not the only direct way to cycle into town. As a result, there is still a reasonable amount of people cycling along the parallel streets, depending on the destinations they are trying to connect to and the cyclist’s personal preferences for route choice. Given that a neighbourhood greenway treatment like this is trying to attract the ‘interested but concerned’ users, it is not necessarily an issue if some more confident existing riders prefer to use other routes.
Full street reconstruction to reduce the width (and hence speed environment) of the roadways was considered for this route; however, this was a costlier option and the street assets still had many years of life remaining. Relatively low-cost traffic islands and other treatments can achieve similar effects on wider streets, at least in the interim. For many road networks with only a small proportion of streets currently due for total renewal at any time, retro-fitting traffic calming into the existing roadway width is a more likely scenario.
Some of the traffic calming is achieved through one-lane sections for motorists, with cycle bypasses on either side. Care was taken during the design to avoid creating a pinch point where a rider using a cycle bypass may be trapped between an overtaking motorist and a parked vehicle. This was achieved through marked no-stopping sections and small kerb islands to keep parking away from the narrowing points.
The speed humps were all individually signposted with an advisory 25 km/h and Council were mocked by The Press with a foreshortened photo showing multiple signs disappearing into the distance. Months later, the speed limit was reduced to 30 km/h. In hindsight, the speed limit should have been reduced when the traffic calming was installed (and thus consulted on earlier during the planning stages), and the advisory speed signs at each hump could then have been omitted.
The route entails some 90-degree turns at intersections, which can be difficult for unfamiliar cycleway users to follow. This issue was largely resolved by reconstructing kerbs to have the priority road follow the cycleway route and by marking regular sharrows on the roadway, which also acted as informal route guidance. Regular wayfinding route signage can also achieve a similar effect; such cycling signage will be installed along this route shortly.
The England / Worcester intersection has deliberately been built tight as it is in a low volume traffic area. It also provides a benefit to the cyclist as the smaller geometry helps to reduce traffic speeds. If a vehicle is turning from the bend into the side road, and a vehicle is waiting at the limit line on the side road, the turning vehicle may not be able to exit due to the space provided. On occasions where two vehicles are at the intersection and the driver has proceeded with the turn, the planting in that corner gets overrun by tyres. Ultimately, more driver patience and courtesy is required between users to negotiate past each other; however, this behaviour change can take time.
While the intersection treatments to restrict through-traffic along England Street are largely successful, some motorists have still been observed undertaking u-turns around the centre islands to perform straight or right-turn movements.
The project team was fortunate that the Associate Transport Minister, Julie Anne Genter, accepted an invitation for the formal opening of stage 1 as that helps with attracting media to report about the event. A local school attended the opening, which helped with getting community buy-in.
Both speed and volume surveys were undertaken before the works proceeded, with post-implementation surveys completed in July 2018. Since opening, motor vehicle volumes along this section of Worcester Street have dropped to below 1000 vehicles/day. Observed 85th percentile traffic speeds are 30 km/h over the speed humps and 35-38 km/h between them. Approximately 120 users a day currently cycle this route (early spring 2018); it should be noted that greater cycling use of the Stage 1 section is not expected until the subsequent sections of the Rapanui – Shag Rock cycleway are completed towards Ferrymead.