A performance analysis of a congested multimodal intersection using VISSIM: A case study of Åkareplatsen, Göteborg
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Åkareplatsen is a complex intersection in the city centre of Gothenburg, Sweden’s
second-largest city, that is utilised by buses, trams, cars, trucks, bicyclists and pedestrians. Since the rebuilding in 2018, Åkareplatsen has been struck by recurring
congestion, gridlocks and accidents. To study this roundabout with tram-crossing
traffic, a model created in VISSIM was analysed, calibrated and validated using 2024
traffic data. This study is limited to what is possible wihtin the bounds of VISSIM.
The method primarily consisted of collecting traffic data in the field and official data,
model calibration and validation, interviews, suggestions for improvements, and a
stress test. To capture the stochastic variability of the model simulations, the sim ulation time was set to 3 hours in 15-minute intervals and was repeated in 10 runs.
Queue length and travel time were the measures of effectiveness (MOEs) used to
compare the model versions and reality during maximum traffic flow. The deviation
between the simulation results and the field measurements was evaluated visually
from video recordings and statistically using Root Mean Square Error (RMSE). The
final model calibration was able to capture realistic diving behaviour and deviated
by 33 minutes and 49 seconds in travel time and 104 m in queue length, an improvement compared to the original model. During validation, it was found that the
calibrated model is about equal at estimating travel time and queue length during
calmer and more dense traffic states. From the simulation results of suggestions for
improvements, removing signal heads for tram-crossing traffic and re-routing some
of the bus lines greatly reduced queues and the number of gridlocks. The stress test
with a higher public density load shows that the suggested design can manage a
50 % increase in public transportation density without extensive gridlocks forming.
Realistic traffic models are time-consuming to build, require a lot of data, and do
not directly reflect reality. Nonetheless, they can be beneficially used to anticipate
traffic-related problems, avoid potential damages they cause, and provide citizens
with their need for mobility.
Beskrivning
Ämne/nyckelord
Åkarepatsen, mulimodal intersection, microsimulation, VISSIM, calibration, validation, RMSE, design improvements