The existing subway system in Toronto is not extensive and does not reach the outer areas of the city. Therefore, the goal of the proposed extension is to reach an area that no existing public transit. With a fast growing population outside of the downtown Toronto core, transit access to outer areas of the city is of growing importance (World Health Organization, 2016). Therefore, given the demand, a new subway line extension is essential.
The analysis conducted showed areas of higher and lower suitability within Toronto's city limits. Given the three proposed lines by Bernardo, Kiralyfalvy, and Smith visual interpretation showed the highest overall suitability in the area associated with the Eastern Scarborough extension. The final suitability did not take cost into account. This factor was considered following the MCE through an average per-kilometer cost.
Using zonal statistics the information regarding suitability was better understood. The Eastern Scarborough line received the highest mean suitability score. As seen with visual interpretation the Eastern Scarborough line appeared to be the most suitable. However, the sum showed the highest value associated with the Humber extension. Considering this was the most expensive line and its mean suitability score ranked the lowest of the three this option was seen as the least suitable choice overall. Next, the Etobicoke extension was analyzed. This extension was the least expensive and ranked second in terms of mean suitability score. If cost became a more important factor due to a multitude of reasons such as funding, this extension may be the best option (Toronto Transit Infrastructure Limited, 2012; Burda & Haines, 2011) . Finally, the Eastern Scarborough extension was examined and ultimately proved to be the best option. This line was deemed the most suitable line for two reasons. Firstly, it was the most suitable line on the final suitability raster visually, and statistically through zonal statistics. Secondly, it is not the most expensive option nor it is the cheapest option. The Eastern Scarborough extension was selected as the most suitable line by concluding that it’s suitability score was more important than it’s cost.
In conclusion, there were many aforementioned strengths and limitations associated with this analysis, which can be found under Objective 4. Three main strengths of this project were outlined. Firstly, the project used an MCE weighted-analysis. This evaluation process allowed the factors to be ranked and considered in terms of importance. Secondly, the use of ArcGIS allowed for the building of maps which are effective visual aids in order to support the research findings of the study. Thirdly, the use of the Zonal Statistics tool in ArcGIS allows the visual conclusions to be solidified with numeric statistics.
However, the study was also subject to many limitations. Firstly, due to time constraints and limitations to the amount of variables allowed in an weighted MCE, six factors were considered. There are likely more factors that affect the suitability of a subway line within a given region, however by not including all factors, the line that was identified as the most suitable could lack accuracy. Secondly, the model does not accommodate for future or projected growth in regions. This limitation restricts the project from accommodating projected growth patterns such as urban sprawl even when these statistics mat be known. Thirdly, the lines selected for the project were originally constructed by Bernardo, Kiralyfalvy and Smith, 2015, and connected to the Toronto Light Rail Transit system. Due to the shift from an LRT system to a subway system, a slight variation in length was created. Finally, the pairwise comparison rankings were determined through literature review and personal judgement. As a result, error may have occurred. Overall, the project deems it’s strengths of the analysis to be more significant than the weakness’ therefore confirming the chosen line as justified.
Suggestions for Further Research
A few pieces of specific information could aid in determining subway line suitability for future studies. In the future these factors could solidify whether or not the chosen line is the best option. A more specific cost per km equation such as one that specifies differing costs based on specific subsurface material, one which includes the cost to build below waterways, or one which includes the cost of building terminals could result in a more accurate determination of the cost of building new subway line. Moreover, a extended time frame to complete the analysis would have allowed for more factors to be considered and included in the Multi-Criteria Evaluation. Lastly, information on population growth associated with where in Toronto the growth is expected to occur would aid in better predicting where transit will be most needed in the future.
We would like to thank Adam Bonnycastle and Nabil Allataifeh for their continued assistance and support throughout the the entirety of this study.