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

DescriptionIn 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 AREA

Create 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 networksNetwork 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%

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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 !