Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Many studies have been conducted regarding network theory and how it can be applied to public
transport network. This has led to knowledge on how network indicators relate to the performance
of a network and also to insights of how networks can best be extended. Little is known however on
how rail bound public transport networks and their network indicators have evolved over time. This
would be interesting to know since many metro and other rail bound public transport networks have
evolved over a long period of time with extensions being made at different times by different policy
makers and stakeholders. This means that there has not been a unified planning process for many of
the networks. It would hence be beneficial to get a better picture of how the networks have evolved,
when extending the networks or when creating new ones.
By creating networks for every year in the development of a rail bound public transport network and
then calculate the different network indicators, the evolutionary trends could be found. The
networks were created in L-space which means that stations were represented as nodes and the rail
connection between stations as edges. To every link in the networks, travel time was attached as
weights. This was done in order to make the network indicators more realistic. By assigning
geographical coordinates to nodes, indicators such as directness and closeness centrality with
respect to geographical distance could be derived.
A case study was conducted by applying the methodology to the Stockholm rail bound public
transport network. The study period was chosen to be from 1950 up until 2025. 1950 was the year
when the Stockholm Metro opened, and the extensions to the network that are decided upon are
planned to be completed in 2025. By including the future extensions it was hoped that it could be
seen if the future trends are following the trends from the 20th century.
Trends regarding the evolution of the network in Stockholm were found. In general it can be said that
indicators were relatively high in the first 15-20 years of the study. This was due to the inner city
tram network that existed in these years. The tram network was relatively intra-connected with a
relatively high average degree, clustering coefficient and connectivity. When the tram network
closed down the indicators drastically decreased, after 1971 many of the indicators started to slowly
increase due to the additions of new lines and also extensions of already existing ones. Between the
year 2000 and 2025, many of the indicators increased substantially, this was partly due to Tvärbanan
that connected many older lines creating nodes with a high degree.
The fact that the future extensions will lead to an increase in many network indicators (and a
decrease in average connectivity) was seen as an indication that the future extensions will
accentuate trends that have taken place since the early 1970’s. It was also seen that many of the
extensions included in this study will help to develop the network in a way that is in line with the
overarching planning principles set by the Stockholm council.
The structure of the network consisted of a dense core with branches reaching out to the suburbs in
the 1950’s and early 1960’s. In the late 1960’s the network got a radial shape with branches going to
the suburbs, no denser core existed in these years. This structure remained relatively unchanged up
until the year 2000. After 2000 and up until 2025 a structure emerged in the network with a dense
core and also a ring line going around half of the city. This type of structure had been seen in many
other rail bound networks around the world.
2014. , 123 p.