Comparing Rail Transit in Seattle, WA and Singapore
How analyzing another city's rail system can aid in developing ours.
Introduction
One of the main goals of public transportation is to connect people to their destination without the reliance on a personal vehicle. On top of this, wide use of public transportation has the added benefits of reducing carbon emissions, decreasing road congestion, and emphasizing the equity of ‘the right to move’ (Hawas et al., 2016). In a growing city such as Seattle where the main area of work is the city center, public transportation accessibility is important in combating long commute times and highway gridlock. Especially with many residents moving into the suburban areas of Kirkland, Lynwood, Renton, Kent, and more (Westneat, 2021), lack of public transit accessibility leads to increased car use and as a result, increased road congestion.
Currently, car ownership in Seattle is relatively high. Using data obtained from the U.S. Census, we can see the percentages of Seattle residents who own no vehicles, one vehicle, or two vehicles. Looking at the bar chart in Figure 1, the percentage of residents who own no vehicles is very low compared to those who own one or two vehicles. The bar chart also tells us that most Seattle residents own one vehicle, with the highest percentage at 43.9% in 2021.
The most significant way of combating transportation issues for the city has been through the expansion of the Sound Transit Link light rail. The Link light rail (which will be referred to as the Link moving forward) strives to connect communities to regional transit options. The current Link stretches from Angle Lake to Northgate with an estimated travel time of 58 minutes from one end to the other.
In addition to the Link, there is the Sounder train which connects Lakewood in the south to Everett in the north with an estimated commute time of 122 minutes. The Link connects many of the inner city neighborhoods whereas the Sounder connects the cities outside of Seattle.
On Sound Transit’s webpage, their stated goal is “connecting more people to more places to make life better and create equitable opportunities for all” (soundtransit.org). As Sound Transit continues to expand their rail network, the big question is likely to be “how can we best improve our transportation to connect more people?”
One way to make improvements is through looking at what others have done and why they are successful. In this situation, analyzing the differences in transportation models can be beneficial in developing and planning the further extension of Seattle’s Link. The model we will be looking at in this StoryMap is Singapore’s rail transit system. Using factors such as quality of infrastructure, user experience, and safety, consulting firm Oliver Wyman calculated a ranking system with the University of Berkeley to find the 15 cities with the best urban mobility. In the finished ranking, Singapore was considered the city with the best transportation solutions (Chenel and Moynihan, 2021). Through comparing the two rail transit models, we can learn why Singapore’s transportation system works well and how Seattle may apply this to the Link expansion.
Methodology
In order to make proper comparisons, this project adopted a similar methodology to Currie’s approach to supply measurement (Currie, 2010). Using data collected from Sound Transit, the Link and Sounder stations along with their routes will be plotted. We will then create a 0.5 mile buffer (as this represents a 10 minute walk on average) and plot pharmacy locations within the Sound Transit district. The same process will be done with Singapore using data obtained through ArcGIS Online Learner. To measure the quality of the transportation system, we will use access to transport, centrality, and accessibility measures as proposed by Puspas in a medium article (Puspas, 2020). The measures are further described below:
Looking at Vehicle Counts
Looking at vehicle counts within each area, we can gain an idea of whether more or less people are relying on personal vehicles in each location. If more vehicles are being used in an area, it is likely that there are less riders using public transit. This information can then be used to access and generally assume which city’s public transit suits the population’s needs. It is also important to keep in mind that this is a generalization and that there will likely be confounding factors that prevent a direct causal relationship. However, looking at the trends of this data can still provide some insight on how vehicle ownership may have changed over time in each city.
Seattle Vehicle Count
Looking at the Seattle vehicle count, we can see that there is a steady increase in personal vehicles. None of the years show a decrease in vehicle count.
Singapore Vehicle Count
Looking at the Singapore vehicle count, there is a difference in trend. There is an increase in vehicle ownership from 2010 to 2013. After 2013, a steep downward spike occurred and vehicle ownership decreased until 2017 where it started to increase again. This trend could possibly indicate that there was less of a reliance on personal vehicles due to the increased quality of public transportation.
Comparing Transit Systems
Seattle Rail Transit
For the rail transit system in Seattle, we will be looking at the Link stations, Sounder stations, and their routes. The Link routes and stations also include those that are currently being developed. In this map, we can see the general shape of the transit lines and how far they stretch within the Sound Transit district. Both the Link and the Sounder routes are relatively linear, stretching south to north with the exception of the new eastern extension to Bellevue that is currently in process. The Sounder trail stations are more widely spread apart whereas the Link stations are closer together. Overall, within the Sound Transit district, there are a lot of areas that these rail networks do not reach.
Singapore Rail Transit
For the rail transit system in Singapore, we are looking at both the MRT and LRT lines along with their stations. In this map, we can see that the routes are highly integrated and spread out within the city-state. The main difference we are seeing between Seattle transit routes and Singapore is the connectivity of the routes. Instead of following one line that moves north and south or east and west, many of Singapore's rail lines connect in circular patterns. In addition, the rail system seems to try cover the entirety of the island, leaving only a small portion of land empty on the northwest edge of the island.
Analysis
In order to show access to transport, a 0.5 mile buffer will be used around each transit station. This number was chosen because it represents a 10 minute walk by the average person. To assess centrality, the number of nodes and edges will be counted for each city. In addition, looking at the maps, we can determine the areas with high or low closeness and betweenness centrality. To assess accessibility, the significant location used was pharmacies. Intersecting these pharmacies with the buffers, we will be able to see and count the number of pharmacies within a 10 minute walk from a station. This process is applied to both Seattle and Singapore.
Seattle Transit System and Pharmacy Accessibility
Left: All pharmacies in Sound Transit district Right: Pharmacies within 0.5 miles of a station
Singapore Transit System and Pharmacy Accessibility
Left: All pharmacies in Singapore Right: Pharmacies within 0.5 miles of a station
Table summarizing the results of the maps above
We can see from the table and maps above that Singapore's rail transit system demonstrates overall higher transportation quality. To measure access to transport, the area of all the 0.5 mile buffers was divided by the total transit system area. This gave us the percentage of land coverage that had access to transport in each city. In Seattle, the percentage of total area that had access to transport was 3.61% whereas in Singapore it was 3.06%. These numbers tell us that although not by a significant amount, Seattle has more access to transport when measured by a 0.5 mile buffer.
Looking at degree centrality, Singapore has significantly more nodes and edges compared to Seattle. In addition, the node to edges ratio is drastically different in Singapore. This shows that unlike in Seattle, one node has multiple edges in Singapore, increasing it's accessibility and connectivity. To measure closeness and betweenness centrality by comparing the maps, we can see that in Singapore, there are more nodes clustered together than in Seattle. In Seattle, the only area with high closeness and betweenness centrality is the city center. In Singapore however, the city center, Seng Kang, Punggol, and Bukit Panjang all have high closeness and betweenness centrality.
Lastly, when making the initial comparison of number of pharmacies within the 0.5 mile buffer, Seattle and Singapore seem to be the same measured accessibility. However, upon further analysis, the number of pharmacies within the buffer to the number of total pharmacies shows the large difference between the two. In Seattle, the number of pharmacies accessible by rail transit is 200 but the total number of pharmacies within the Sound Transit district is 845. In Singapore, the number of pharmacies accessible by rail transit is 245 and the total number of pharmacies is 269. These results show that overall, Singapore's public transit is of higher quality and more accessible compared to Seattle.
Conclusion
As Seattle continues to expand the Link, it is important to account for accessibility along with interconnectedness. Especially with the population of the city increasing, a better public transit system can help in decreasing reliance on personal vehicles and in turn, lessen traffic congestion. Through comparing our current and planned rail transit routes with Singapore's, we can gain more insight on how to improve our system. Similarly to Singapore, we can extend beyond the Link's linear flow and implement more stations with multiple connecting routes in the future. Using the results from comparing to another city with exceptional public transportation, Seattle's transit planners can better understand and execute routes to truly connect all residents of the city.
Sources
References
Chanel, T. and Moynihan, Q. (2021). 15 cities that are home to some of the world’s best transport solutions. Business Insider France. https://www.businessinsider.com/15-cities-worlds-best-transport-solutions-2019-12
Currie, G. (2010). Quantifying spatial gaps in public transport supply based on social needs. Journal of Transport Geography. 18(1), 31-41. https://doi.org/10.1016/j.jtrangeo.2008.12.002
Hawas, Y. E., Hussan, M. N., and Abulibdeh, A. (2016). A multi-criteria approach of assessing public transport accessibility at a strategic level. Journal of Transport Geography, 57, 19-34. Doi: https://doi.org/10.1016/j.jtrangeo.2016.09.011
Miller, E. J. (2018). Accessibility: measurement and application in transportation planning. Transport Reviews. 38(5), 551-555. https://doi.org/10.1080/01441647.2018.1492778
Puspas, J. (2020). Measuring Quality of Urban Public Transport. Medium. https://medium.com/vesputi/measuring-quality-of-urban-public-transport-3f2e5fda666a
Westneat, D. (2021). Seattle shrinking? Seattleites moved out in droves in 2020, though most didn’t go far. The Seattle Times. https://www.seattletimes.com/seattle-news/seattle-shrinking-seattleites-moved-out-in-droves-in-2020-though-they-didnt-go-far/
Seattle Data Sources
Pharmacies: https://doh.wa.gov/data-statistical-reports/data-systems/geographic-information-system/downloadable-data-sets
Transit data: https://www.soundtransit.org/help-contacts/business-information/open-transit-data-otd/otd-downloads
Vehicle counts: https://data.census.gov/table?tid=ACSDP5Y2021.DP04&g=0400000US53_1600000US5363000&hidePreview=true
Singapore Data Sources
Vehicle counts: https://data.gov.sg/dataset/annual-motor-vehicle-population-by-vehicle-type
Pharmacies: https://www.onemap.gov.sg/home/
Transit stations and routes: https://www.arcgis.com/home/item.html?id=b6c521bf02fc46b8887c7af0d071b483
