Improving the base network

The walking network in district centres and business retail parks as defined by the Christchurch city plan (Christchurch City Council 2005) was edited manually using aerial photographs as a guide in order to achieve an increased level of accuracy. This included the addition of off-road walking links and the removal of edges from the base walking network, where the aerial photograph indicated no formed footpath existed.

The base walking network within the district centres and business retail parks was deleted and recreated manually as the base network did not provide an acceptable level of quality. Each walking link within a district centre or business retail park was identified with a type attribute of CARPARK, CARPARK_PUBLIC or OPEN AIR MALL in accordance with the link type. Only outdoor walking links were recorded in the walking network.

Road crossing links within district centres or business retail parks were also digitised manually from aerial photos and these links were given the value ROAD for the intersection attribute. The attribute for the street name of a road crossing is the street name of the road that is being crossed, not the street which runs parallel to the road crossing.

The locations of zebra crossing links were added to the GIS city-wide walking network GIS layer and confirmed using aerial photographs. Each zebra crossing link was given the intersection attribute ZEBRA.

Intersections that included traffic signals were recorded on the walking network. These intersections were deleted from the base network and re-created using aerial photos. This was especially important where intersections used a combination of traffic lights, traffic islands and pedestrian crossings. Traffic signal intersection links were assigned with an intersection attribute of LIGHTS.

Data from the Christchurch City Council included information regarding the traffic signals location, identification number and phasing (the order vehicular and pedestrian traffic is allowed to move). It also indicated which road crossings at the intersection allowed for dedicated pedestrian movement. Once the intersection was identified, the aerial photograph covering the area was used to ensure accuracy of data editing and input of the related links. Each crossing link was given a percentage value based on the frequency the crossing was available for pedestrians to cross. This percentage information is recorded in the PERCENTAGE attribute field of the walking network.

Walking links that were not along public roads, and therefore not included on the base network, were coded using a combination of aerial photographs and land-zoning data from three categories outlined in table 14.4.

Table 14.4    Land-zoning data

Zone type

Zone name

Description

Open space zones

Open space 1 zone

Small areas of public open space which are of value to local neighbourhoods and communities

Open space 2 zone

Large areas of public open space for active recreation which serve a suburban or district-wide function

Open space 3 zone

Large public recreation areas, may be associated with areas of open parkland

Conservation zones

Conservation 2 zone

Public parks of city-wide significance which help provide the city with its unique scenery and character

Conservation 4 zone

Most of the cemeteries which are currently operating. Other cemeteries that have significant heritage value are zoned in conservation 2 to provide greater recognition of their historic values

Cultural zones

Cultural 4 zone

Campuses of tertiary education facilities

 

For each walking link running through one of these six zones mentioned above, the code was assigned to the ‘type’ attribute. For example, a walking link running through Hagley Park was assigned ‘O2’, as Hagley Park is zoned ‘open space 2’. This later enabled the turning ‘on’ or ‘off’ of specific links depending on the accessibility analysis being undertaken.

Bus routes in the city were used in conjunction with aerial photographs to identify pedestrian refuges in high-priority locations. Each bus route was inspected to ensure all pedestrian refuges along it were located. The network links running through the pedestrian refuges were manually coded with the intersection attribute of REFUGE and added to the citywide walking network layer.

A particular feature that affects people’s propensity to walk is the presence or absence of streetlights on links for walking during the hours of darkness. In the UK it has been found that some households have very poor access during the hours of darkness due to the inability to travel along unlit streets during the hours of darkness. Any feature such as this can be added to the walking network model by marking a link as inaccessible during particular time windows. Time windows become particularly important when looking at walking links to public transport and the inability of safe walking links can be a critical barrier to access.