Transit Analysis Tools 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 are the Transit Analysis Tools?

These instructions explain how to use the supplemental Transit Analysis Tools with the transit network dataset you created using Add GTFS to a Network Dataset. These tools are designed to help you explore your data and understand the results of network analysis using transit.

Copy Traversed Source Features (with Transit)

The ArcGIS Network Analyst tool Copy Traversed Source Features produces feature classes showing the network edges, junctions, and turns that were traversed when solving a network analysis layer. It shows the actual network features that were used. The Copy Traversed Source Features (with Transit) tool is an extension of the ArcGIS tool designed for use with transit network datasets. It adds GTFS transit information to the traversal result produced by the ArcGIS Copy Traversed Source Features tool. GTFS stop information is added to the output Junctions. GTFS route information, trip_id, arrive and depart time and stop names, and the transit time and wait time are added to the output Edges for each transit leg. An additional feature class is produced containing only the transit edges.

Learn more about the original Copy Traversed Source Features tool and the output from that tool in the ArcGIS documentation.

Screenshot of tool dialog

Inputs

Outputs

All output will be created in the file geodatabase you specified in the tool inputs.

Notes about the Edge output

Prepare Time Lapse Polygons

The results of analyses performed using your GTFS-enabled network dataset can vary greatly depending upon the time of day used as the start time for your analysis. An analysis run at 8:00 AM might have a very different solution than one run at 8:01 AM if the traveler has just missed the bus.

A demonstration of this time dependency can be seen in this video. The video is a time lapse showing the area reachable within 15 minutes of travel time by walking and public transit from a point in Atlanta. Because the available transit service changes throughout the day, the area reachable changes significantly depending on the time of day you leave on your journey. For this video, I incremented the start time in one-minute intervals for each minute between 10:00 AM and 11:00 AM on a typical weekday and put the results in a time lapse.

The Prepare Time Lapse Polygons tool will help you to make a video like this of your own. This involves three steps:

  1. Prepare a Service Area layer in the map
  2. Run the Prepare Time Lapse Polygons tool
  3. Create your time lapse video from the resulting polygon feature class in ArcMap or ArcGIS Pro.

1. Prepare a Service Area layer in the map

After creating your GTFS-enabled network dataset using the Add GTFS to a Network Dataset toolbox, create a Service Area network analysis layer in the map for the facility or facilities you want to analyze, and configure the layer with the correct analysis settings. Solve it for a few different times of day to make sure it works and that you get the results you want.

2. Run the Prepare Time Lapse Polygons tool

Once your Service Area layer is prepared, run the Prepare Time Lapse Polygons tool to solve the service area for a range of start times and save the output polygons to a feature class. You can use this feature class to make a time lapse video.

Screenshot of tool dialog

Inputs

Outputs

The resulting polygons feature class will contain one row per Service Area per time of day solved when running the tool. The feature class will contain a field called TimeOfDay indicating the traveler's start time.

If you used a generic weekday instead of a specific date, the date portion of the TimeOfDay field will show dates in 1899 or 1900. This is "correct", in that these are special reserved dates used by ArcGIS Network Analyst to indicate generic weekdays.

3. Create your time lapse video

Once you have generated your polygons feature class, you can use it to create a time lapse video in either ArcMap or ArcGIS Pro.

ArcMap

First, enable time on the output polygons layer. Open the layer properties, go to the Time tab, and chose "Enable time on this layer". Adjust the settings as shown in the screenshot. Make sure to set the Time Step Interval to the number of minutes you used when you ran the Prepare Time Lapse Polygons tool.

Screenshot of enabling time on a layer

After you have done this, you can follow the steps in the ArcMap documentation for exporting a time visualization to a video. For some help using the Time Slider to prepare your video, check out this documentation.

ArcGIS Pro

Although you cannot use ArcGIS Pro to create your GTFS-enabled network dataset or run analyses with it, you can use the feature class created with the Prepare Time Lapse Polygons tool make your time lapse video in ArcGIS Pro. Please check out the ArcGIS Pro documentation for how to do this.

Transit Identify

The Transit Identify tool is a network debugging utility that will print the transit schedule for the selected transit line in the network. If you make a selection on the TransitLines feature class that participates in your network dataset, the Transit Identify tool will print a list of the times of day and days of week the selected line feature is traveled across.

You can use this information when testing that your network is working correctly. For instance, if you suspect that the transit lines are ever being used in your analysis and you want to make sure your network connectivity is correct, you can use this tool to help you check the behavior of your network.

Debugging procedure

This tool is not meant to be used to extract schedule information from the entire network; consequently, the tool will only run if the number of selected features is 5 or fewer.

Screenshot of tool dialog

Inputs

Outputs