Shin Huoy's GIS Portfolio
A GIS-based cycling path planning in Singapore: A case study of Woodlands Planning Area
By Terh Shin Huoy
This project was a self-proposed Honours Thesis project under the NUS Department of Geography in fulfilment of my undergraduate requirements. I was mentored by Dr Cao Kai.
Abstract
Singapore introduced the National Cycling Plan to increase cycling infrastructure by 2030. Given Singapore’s land constraints, planning the most effective cycling network is critical. Moreover, there has been growing pressure to incorporate public participation in planning decisions. In order to achieve optimal planning outcomes and greater transparency in planning, multiple criteria and the perspectives of different stakeholders need to be considered. This thesis proposes a Geographic Information System-based multi-criteria decision analysis (GIS-MCDA) framework for the planning of cycling paths in Singapore. It is positioned to address the lacuna in the literature that is dominated by western-centric case studies and a fixation on only infrastructural and objective factors in the planning of cycling paths. The proposed cycling path planning support framework will be implemented for Woodlands Planning Area (WPA). The primary research questions are where to build cycling paths in WPA and whether the cycling paths to be built will change based on different stakeholders’ preferences. Questionnaires are conducted to obtain the views of the public, transport experts and government planners on the relative importance of nine criteria in the planning of cycling paths. The nine criterion raster layers are combined according to their relative importance to each stakeholder using the Weighted Linear Combination model. The results show the areas where new cycling paths should be prioritised in WPA and demonstrate that the existing cycling network in WPA is inadequate. Furthermore, cycling paths preferred by the government planner and public are largely similar, whereas the paths prefered by the transport expert differ slightly. The cycling path planning support framework is able to visualise different stakeholders’ preferences and model various scenarios, hence can improve the engagement between stakeholders and contribute to greater transparency in Singapore’s planning processes. The framework has the potential to be applied to other planning problems.
Methodology
1. Criteria identification
A list of criteria to be evaluated in the planning of new cycling paths is derived by reviewing academic publications, cycling planning manuals from other countries, and e-mail correspondences with avid cyclists. The nine criteria identified include: slope, human traffic, distance from major roads, proximity to educational institutions, proximity to retail developments, proximity to employment zones, proximity to community amenities, proximity to bus stops and proximity to MRT stations.
2. Obtaining criteria weights
A key objective of this thesis is to incorporate MCDA and participatory planning approaches in order to derive a more holistic cycling network that caters to the needs and preferences of different stakeholders. The three key stakeholder groups considered in the MCDA are the public, the transport expert and the government planner. Online questionnaires were used to obtain the public's views. Questionnaires were also e-mailed to transport experts in Singapore and government planners. Respondents are asked to rank the relative importance of the criteria on a Likert- type scale between 1 and 7, with 1 being least important and 7 being most important.
3. Multi-criteria decision analysis
The GIS dataset for each criteria was multiplied by its respective criteria weights to obtain maps of suitable locations to build cycling paths in Woodlands Planning Area. This was following the Weighted Linear Combination rule:
where V(Ai) is the overall value of the i-th alternative (represented by a raster cell) at the location defined by coordinates (xi, yi), and v(aik) is the value of the i-th alternative with respect to the k-th criterion.
Results and Discussion
The figure below shows the GIS datasets obtained for the nine criteria. The criteria were range-standardized such that the most suitable areas for building cycling paths have a value of 1 and the least suitable areas for building cycling paths have a value of 0.
After combining the nine criteria according to their relative weights, these maps show the suitable areas to build cycling paths according to each stakeholder's preferences.
By extracting the suitability map of the combined stakeholders' preferences to existing footpaths in Woodlands Planning Area, this map shows the suitability of building new cycling paths along existing footpaths in the area based on the combined stakeholders' views.
Lastly, the preferred routes according to each stakeholder was modelled using the 'Cost Distance' and 'Cost Path' tools in ArcMap.
Conclusion
Based on the analysis, there are two main areas where cycling paths should be prioritised in Woodlands Planning Area, and there are few differences when the preferences of different stakeholders were modelled. Notably, the preferences of the government planner and the public are extremely similar, demonstrating that the government planner has a good understanding of the public’s needs and perspectives.
This cycling path planning support framework is able to incorporate participatory planning approaches into the decision-making process, hence has implications on enhancing the transparency of urban planning decisions in Singapore. In addition to qualitatively analysing the preferred routes between different origins and destinations, future studies can consider incorporating quantitative estimations of number of trips along each footpath segment can further enhance the cycling path planning. This can be done by incorporating the predicted cycling demand along each route and obtaining the footpath segments with the highest cycling demand.
Note: This is a summarised version of my full thesis (12,000 words). Please e-mail me if you wish to read my full thesis!