Introducing Transport Analyst
We are proud to announce the release of Transport Analyst, a web based application for transport accessibility analysis powered by OpenTripPlanner (OTP). This application was developed in collaboration with the World Bank to create analysis and data management tools in support or improved transportation outcomes in cities around the globe.
OpenTripPlanner already powers numerous analytic applications, however, Transport Analysis adds important new functionality to OTP and provides a powerful web-based user interface that enables a broader audience of users to develop and run transport analysis applications. In addition to releasing the source Conveyal offers a fully-hosted Transport Analyst application as a service. Contact us for more information.
Transport Analyst enables the measurement of access to spatially distributed variables (people, jobs, schools, etc.) via public transport, walking, biking or driving. Common applications include measuring access to jobs, workforce, or key locations as an indicator of transport effectiveness. Indicators can be combined to create composite regional measures, such as a population-weighted average job access for a neighborhood or an entire city.
The application does not prescribe specific research questions. It accepts data in standard Shapefile (spatial) and GTFS (public transport) formats. Users may import and analyze any data set matching these formats.
Analysis showing the before and after impact of a hypothetical infrastructure change. Colors indicate change in access (yellow: no change, blue: faster access, pink: previously inaccessible within time limit)
Single-point Analysis
The basis for all analysis in Transport Analyst is the access to or from a given point location (or origin) as a measure or what can be reached in a given time window. Single-origin analysis can be conducted by selecting the variable to measure (e.g. jobs) and clicking on the map to define a start location. A travel time and access plot is created showing the distribution of travel times to the selected location and variable.
Settings allow selection of the transport scenario, travel mode, date, time window, and variable to measure accessibility to. Travel times are reported as best case, worst case or average for the given time window.
Regional Analysis
Regional Analysis functions allow the automation of many single-point queries, one from each potential origin location (for example, every Census block). Once computed, regional analysis outputs show variation in travel accessibility for potential users at any location within the study area. Due to the number of queries involved these may take from minutes to hours to compute.
Aggregation and Bertaud Measure
Once analysis has been conducted at a regional scale it often makes sense to aggregate data to a larger spatial unit.
For example, one useful and easily calculated measure is defined in Alain Bertaud’s Cities as Labor Markets. This measures the average number of jobs that can be accessed within 60 minutes weighted by population. This enables fine-grain calculation of job access at a block level to be summed and converted to an average metric of access at a municipal scale.
Transport Data
Public transport routes and schedules are imported from GTFS data sets using the Transport Data interface under the “Data” menu. Simply upload a valid, zipped GTFS archive and Transport Analyst will automatically create a transport model for the area included in the feed. Create as many different transport scenarios as you wish. Each scenario can be analyzed separately or compared against the others to measure accessibility impact of different transport systems, either existing or hypothetical.
Creating GTFS
If GTFS is not already available an approximate transit network and schedule can be quickly derived from a GIS data set containing route alignments and, optionally, stop locations.
Alternatively you can use GTFS Editor, a web-based visual tool for creating and maintaining transit schedules.
Shapefiles
Shapefiles provide the basis for all measurements within Transport Analyst. Upload spatial variables either as a point or thematic data set. The numeric attributes within the data set can be summed as part of the accessibility measure (e.g. total job access from location x).
OpenStreetMap
Data for pedestrians, bicycles and cars is imported directly from OpenStreetMap.
