Evaluation of Geographic Information Systems Spatial Analysis Tools in the Resolve
of Service Areas for Transportation Systems: Case Study of the Bus Rapid Transit Transmilenio Station “Portal
Norte”Daniel Páez Universidad de los Andes
Summary
Introduction Methodology
o Buffero Service Areao Analysis
Results (Case of study Bogotá) Conclusions
Methodology
BRT Network Analysis
Description
This research will study two methodologies to evaluate the accessibility to the public transportation. The main objective is to evaluate two methodologies (buffer and network analyst) that identify the accessibility around a transit station
Analysis
Public transportation is a good and sustainable alternative for the people with or without a car. It is economic and in some cases faster than the private vehicle.But the accessibility could be a problem for the service, the people have to walk through long distances, and have to wait long times to take the transport.
Methodology Buffer
Description
In the first methodology, we study the accessibility making use of the buffer tool.The buffer tool creates a polygon around an input within a specifically distance. We made an accessibility analysis with an influence area of 500 meters around the entrance to the station.
Results (Case of study Bogotá)
Station Context
The station for the study is the Portal Norte. It is a Transmilenio Station, a BRT in the city of Bogotá, Colombia. The station has a demand of 45 000 people per week, It attracts people because their influence area and the feeder bus service.
Results
BUFFER
Source: Scramento County planning office
Methodology Network analyst tools
DescriptionIn the second methodology, we study the accessibility making use of the network analyst tools. The network analyst tools has a tool called service area that creates a polygon around the transport network within a specifically distance and with some restrictions and a generalized cost associated with each link.
Results
SERVICE AREACreate the links
of the pedestrian network
Pedestrian network without
delays
Pedestrian network with
delays
Create influence area for the
networks
Create the links of the pedestrian network
The network was created for the pedastrian mobility. This network is important to identify the accesibility for the people to access to the Transmilenio.
For the analysis the walking velocity is 4,5 km/hr (1.5 m/s)
Results
Pedestrian network without delays
The generalized cost of the network only takes into account the time to walk through a distance.
Results
Pedestrian network with delays
The generalized cost of the network takes into account the time to cross through a distance, the time to cross intersections and the time of delay of the traffic
Create influence area for the networks
Network without delaysNetwork with delays
Results
Comparison of the methodologies
Tool Influence Area (square meters) Rate tool to bufferBuffer 785.191,17 100%Service area without delay 396.890,49 50,50%Service area with delay 352.624,34 45%
Tool # of habitants Rate tool to bufferBuffer 9.555,00 100%Service area without delay 4.914,00 51,43%Service area with delay 4.500,00 47%
* *
Conclusions
The network takes into account a generalized cost, it is noticed that this methodology is closer to the reality than the buffer methodology. The service area depends on the delay of several factors, not only the studied in the research.
The service area methodology has fixed parameters, like velocity or the distance of the influence area, the results are limited to this specifically case, However, the methodology is applicable to any transport system in the world if the input data is known, but the results will be different.
Each tool is useful but it is important to know the scope of the tool and the purpose of the analysis; determine which tool fits better to find relevant results.
In the transportation analysis the service area works better because it doesn’t oversize the results, it has restrictions with the generalized cost. The results are comparable with the reality
THANKS !