Better Bus Buffers User's Guide

Created by Melinda Morang, Esri
Contact: mmorang@esri.com

Copyright 2017 Esri
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

What this tool does

BetterBusBuffers is a toolset to help you quantitatively measure access to public transit in your city. The tools use GTFS public transit data and ArcGIS to count the number of transit trips available during a time window for areas within your city, point locations within your city, along specific corridors, or at the transit stops themselves.

Overview of the BetterBusBuffers tools

The Preprocess GTFS tool converts your GTFS dataset(s) into a SQL database. This SQL database is used as input for all the other BetterBusBuffers tools. You should run this tool first.

The Count Trips for Individual Route tool allows you to examine individual routes in your system in detail. It generates a feature class of transit stops associated with the route you select as well as polygon service areas around the stops, and it calculates the number of visits, frequency, max wait time, and average headway for each stop during a time window.

The Count Trips in Polygon Buffers around Stops tool generates polygon service areas around all the stops in your transit system and counts the number of transit trips available in those areas during a time window. The output is a transit coverage map that can be color-coded by the number of available trips.

The Count Trips on Lines tool counts the number of transit trips that travel along corridors between stops during a time window. The output is a lines feature class that can by symbolized to emphasize high-frequency corridors and connections.

The Count Trips at Points tool counts the number of transit trips available within a designated distance of specific point locations during a time window. The output is a copy of the input point locations with fields indicating the number of transit trips available within a short walk during a time window.

The Count Trips at Points Online does the same thing as the Count Trips at Points tool, but it uses the ArcGIS Online Origin-Destination Cost Matrix service so that you don't need your own network datasets or a Network Analyst license.

The Count Trips at Stops tool counts the number of transit trips that visit the stops in your transit system during a time window. The output is a feature class of your GTFS stops with fields indicating the number of transit trips that visit those stops.

The Count High Frequency Routes at Stops tool counts the number of routes at each stop that meet a desired headway threshold. The output is a feature class of your GTFS stops with fields indicating trip and headway statistics along with a count of the number of routes at the stop that has headways of a desired threshold or shorter.

Detailed instructions for each of these tools is given later in this document.

Software requirements

Data requirements

Getting started

Workflow

  1. After preparing the toolbox and your data, run the Preprocess GTFS tool. The output for this tool will serve as input for all the other tools in the toolbox.
  2. Run whichever other tools you are interested in. Details about how to run these tools are below.

Running Preprocess GTFS

What this tool does

The Preprocess GTFS tool converts your GTFS dataset(s) into a SQL database. This SQL database is used as input for all the other BetterBusBuffers tool. You should run this tool first. You only need to run this tool once for any GTFS dataset or set of datasets you wish to analyze.

Screenshot of tool dialog

Inputs

Outputs

Troubleshooting & potential pitfalls

Running Count Trips for Individual Route

What this tool does

The Count Trips for Individual Route tool finds the stops used by a particular route in your system, generates polygon service areas around those stops, and calculates some statistics about the number of trips that visit those stops during a time window. The output is a feature class of stops and a feature class showing the area served by the route, along with fields indicating the number, frequency, max wait time, and average headway for that route during the time window you select.

Workflow

This tool contains two parts. Step 1 need only be run once for a given route and buffer size (for example, Route 10x and 0.25 miles). Step 1 creates the stops and service area feature classes. Step 2 uses those feature classes as input. In Step 2, you select the time window you wish to analyze, and the results are added to the feature classes. Re-run Step 2 for each time window you wish to analyze.

Step 1 – Preprocess Route Buffers

This tool requires a Network Analyst license.

Screenshot of tool dialog

Inputs

Outputs

All output files are written to a file geodatabase with the name and output directory you selected.

Step 2 – Count Trips for Route

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This tool produces a polygon buffers around each transit stop used by the route you selected to analyze. These polygons will often overlap. This is normal. The Stops and Buffers feature classes both contain information from the stops.txt GTFS file for each stop. They also contain the route_id and direction_id (which should be the same for all features in a single feature class). Step 2 adds the following fields to your feature classes:

Running Count Trips in Polygon Buffers around Stops

What this tool does

The Count Trips in Polygon Buffers around Stops tool generates polygon service areas around the stops in your transit system and counts the number of transit trips available in those areas during a time window. The output is a transit coverage map that can be color-coded by the number of available trips in order to highlight the transit frequency in different parts of your city.

Workflow

This tool contains two parts. Step 1 need only be run once for a given geography and buffer size (for example, Chicago and 0.25 miles). Step 1 simply creates some feature classes to be referenced by Step 2. Step 1 can take a very long time to run. In Step 2, which generally runs quicly, you select the time window you wish to analyze and generate the useful output. Re-run Step 2 for each time window you wish to analyze.

Step 1 – Preprocess Buffers

This tool requires the Desktop Advanced (ArcInfo) license and a Network Analyst license.

Screenshot of tool dialog

Inputs

Outputs

All output files are written to a file geodatabase with the name and output directory you selected.

Step 2 – Count Trips in Buffers

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This tool produces polygon buffers around the transit stops in your network in order to show the area covered by transit service. However, often stops in the network are close enough together that their polygon buffers overlap. In these cases, the tool breaks up the original, overlapping buffers so that the overlapping area has its own polygon. This way, a separate trip count can be produced for the overlapping area, since that area has access to all the trips that visit each of the stops within range. Because the overlapping areas are counted separately, the output from this tool will have a very large number of polygons, generally many more than the number of stops in your network.

Diagram of overlapping Service Area polygons

This tool produces a polygon feature class containing the fields described below. Note: The field names are shortened for shapefile output.

Troubleshooting & potential pitfalls

Running Count Trips on Lines

What this tool does

The Count Trips on Lines tool counts the number of transit trips that travel along corridors between stops during a time window. The output is a lines feature class that can by symbolized to emphasize high-frequency corridors and connections. You can choose whether you want to combine all routes along a particular corridor (make only one line representing all routes between the same pair of stops) or not (make a separate line for each separate GTFS route_id traveling between the same pair of stops).

The lines produced are simply straight lines between connected stops rather than the actual paths traveled by the transit vehicles as represented in shapes.txt.

Workflow

This tool contains two parts. Step 1 need only be run once for a given transit system. It creates a template feature class of transit lines that is used as input to Step 2. In Step 2, you select the time window you wish to analyze, and the results are added to a copy of the template feature class. Re-run Step 2 for each time window you wish to analyze.

Step 1 – Preprocess Lines

Screenshot of tool dialog

Inputs

Outputs

Step 2 – Count Trips on Lines

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This lines produced in Step 1 are simply straight lines between each pair of connected stops in your GTFS dataset. They do not represent the actual paths traveled by the transit vehicles as represented in shapes.txt. If the Combine routes along corridors parameter is true, then there will be only one line between each pair of connected stops. If it is false, then there will be one line per unique route_id. There may be multiple overlapping lines if multiple routes travel between the same pair of stops.

Step 2 adds the following fields to your feature classes:

When displaying the results of Step 2 in the map, the "Graduated symbols" symbology type under "Quanitities" is helpful. Symbolize corridors with more frequent service using wider, bolder lines.

Running Count Trips at Points

This tool requires a Network Analyst license.

What this tool does

The Count Trips at Points tool counts the number of transit trips available within a designated distance of specific point locations during a time window. For example, you could use this tool to find the number of transit trips within a quarter mile walk of all the supermarkets in your city between 3pm and 5pm on a Monday. The output shows the total number of trips, the average number of trips per hour, and the maximum time between available trips. You can use the symbology settings of the resulting feature class to highlight the frequency of service for your points. Note that the tool tells you nothing about the destination of the transit trips that serve the input points, only how many of them there are.

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This tool produces a points feature class containing the fields described below. Note: The field names are shortened for shapefile output.

Troubleshooting & potential pitfalls

Running Count Trips at Points Online

What this tool does

Count Trips at Points Online does the same thing as Count Trips at Points, but instead of using a network dataset to calculate the distance between your input points and nearby stops, it does this using the ArcGIS Online origin-destination cost matrix service.

ArcGIS Online's origin-destination cost matrix service is available for most parts of the world. If you are uncertain whether the service covers the geographic location served by your transit system, check the ArcGIS Online Network Dataset Coverage map.

To use this tool, you must be signed in to an ArcGIS Online account, or you must enter your ArcGIS Online username and password into the tool dialog. Your ArcGIS Online account must have network service privileges and sufficient credits. Talk to your organization's ArcGIS Online administrator if you need help checking or setting up your account.

This tool will calculate at maximum one route per origin-destination pair. So, if you have 100 points of interest and 100 transit stops, the travel time or distance will be calculated between, at maximum, 100*100=10000 origin-destination pairs. However, the Count Trips at Points Online tool attempts to minimize the number of origin-destination calculations made by spatially chunking the problem, so the actual number of origin-destination pairs will probably be far less.

As of this writing, the "Origin Destination Cost Matrix" service costs 0.0005 credits per origin-destination pair. If all 10000 origin-destination pairs from the example above were passed to the service, it would cost a total of 5 credits. Please refer to the ArcGIS Online Service Credits Overview page for more detailed and up-to-date information.

If you don't want to or can't use ArcGIS Online, use the Count Trips at Points tool instead.

Note: The Count Trips at Points Online tool cannot be run with ArcGIS 10.0. Please use a newer version of ArcGIS.

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

Please see the "Understanding the Output" section for the Count Trips at Points tool. The output fields are the same.

Troubleshooting & potential pitfalls

Running Count Trips at Stops

What this tool does

The Count Trips at Stops tool counts the number of transit trips that visit the stops in your network during a time window. The output is a feature class of your GTFS stops with fields indicating the number of transit trips that visit those stops. You can use the symbology settings of the resulting feature class to highlight the frequency of service for stops in your network.

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This tool produces a points feature class containing the fields described below. Note: The field names are shortened for shapefile output.

Troubleshooting & potential pitfalls

Running Count High Frequency Routes at Stops

What this tool does

The Count High Frequency Routes at Stops tool counts the number of routes at each stop that meet a desired headway threshold. The output is a feature class of your GTFS stops with fields indicating trip and headway statistics along with a count of the number of routes at the stop that have headways of a desired threshold or shorter.

Screenshot of tool dialog

Inputs

Outputs

Understanding the output

This tool produces a points feature class containing the fields described below. Note: The field names are shortened for shapefile output.

Troubleshooting & potential pitfalls