What is the Schedule Data Profile (SDP)?
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The SDP is a data exchange format that describes a transit agency’s service information.
Examples of data described by the SDP are expected bus arrival times, train schedules, transit stop and
facility information, as well as other data related to transit schedules. The SDP was developed to meet
the diverse needs of both large and small transit agencies, including regional operators that use multi-modal
facilities. Its goal was to provide an efficient, standards-based, framework to assist the public transit
providers with managing and exchanging schedule data.
Although the SDP is currently being used primarily as a data exchange format, it has additional value to
transit agencies as it is based on a conceptual data model that can assist transit Information Technology
departments and ITS project managers. Among the valuable components of the SDP are the development of standard
terms and definitions pertaining to transit schedule data, the XML Schema and the Reference Data Model.
The model describes transit service information, including service and facility information related to multi-modal
and multi-agency environments.
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How was the SDP developed?
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The SDP was sponsored by the New York State Department of Transportation
and was developed by transit operators in New York State with other regional transit operators in a consensus driven
process. They worked together to identify downstream application data needs, data requirements and business rules
related to collecting, documenting, integrating, and disseminating transit service information for their complex
operating environment. The SDP emerged from this effort and is being actively maintained by a Technical Working
Group that represents those operators.
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How do I learn more about SDP? |
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The development process and related systems engineering documents for the SDP are described in:
SDP Development Process .
A Quick Start Tutorial that describes the SDP XML Schema is available on-line.
In-depth guidance and tools are available on the SDP Guidance Documents page.
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What formats does the SDP use to exchange schedule-related data? |
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The SDP is available in two formats:
- XML Document based on the SDP Schema
- Comma delimited text files (csv) based on the SDP logical data model
The XML schemas and the csv file descriptions are briefly described below and additional information about them can be downloaded.
The main SDP schema is composed of four files:
- SDP_XML_Schema_V1_1.xsd (top level schema, defines branches and constraints)
- SDP_common_V1_1.xsd (description of complex elements)
- SDP_domain_V1_1.xsd (description of codes and simple elements)
- GML_geometry.xsd (excerpt of PolygonType from Geographic Markup Language)
In addition, another schema that describes a schedule calendar is composed of two files:
- SDP_Schedule_Calendar_Date_v1.xsd (top level schema)
- SDP_domain_scd_V1_0.xsd (same as SDP_domain_V1_1; describes codes and simple elements)
The main SDP schema and the Schedule Calendar Schema are zipped into separate files and are available for download with
sample XML document instances from:
SDP Schemas.
The SDP CSV file descriptions are based on the SDP logical data model. The format for each file can be downloaded from:
SDP CSV file format.
The SDP Forum website hosts several scripts that translate data between SDP csv and XML formats, and between SDP csv and
GTFS formats.
The scripts are licensed under an open source BSD license and are available from
Translation Scripts.
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How are SDP documents validated? |
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The SDP and GTFS data must pass both the GTFS and SDP validation tests in order to be made available to the public.
The validation process is described in the document found at:
SDP Validation Process
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What is the difference between SDP and GTFS? |
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The SDP was developed to meet a diverse range of uses of transit schedule data by transit agencies.
As a result, SDP covers data concepts that are not in GTFS. In other words, GTFS meets some, but not all
the requirements placed upon the SDP by the New York transit agencies and other regional stakeholders.
The key data concepts that are in SDP, but not in GTFS, as of January 2010 are listed below:
- Pattern descriptions
- Timetable header format definition
- Event connections that specify guaranteed and recommended connections between trips
- In-service head sign descriptions that are assigned to trip times
- Comprehensive multi-modal transit facility information that describe associated plant components such
as amenities, portals (entrances/exits), passenger access components (elevators/escalators/moving walkways),
and stops / platforms
- Location reference "table" that includes all location information in a single file.
- Ability to generate ad hoc and interim revisions to a schedule version on a route basis.
- Cluster of stops that allow transfers. The Transfer Cluster includes a description of connection
directions between boarding and alighting locations.
- Special transit path descriptions that may not exist on the transportation network (or base map)
such as a bus-only lane or route segment.
In addition, SDP will be generating integrated, multi-agency data sets. The features included in these data sets include:
- Multi-agency transit facility and connection directions for key multimodal facilities in NY
- Transfers (guaranteed and recommended) between agencies in the region
- Fare transfer cost information between agencies
Similar to GTFS, the SDP provides a format that transit operators can use to describe aspects of their services.
Many transit agencies in the state of New York only provide basic schedule-related service information, often because
they do not collect the additional data elements.
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What Transit Providers use SDP? |
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New York transit agencies that submit their data to the 511NY have had their data converted to the SDP XML format.
Several agencies use a special tool, the Web Data Maintenance System (WDMS) to input and check their data.
The WDMS then translates the data to the SDP XML format. The Data Provider Translation Process
shows how different transit agencies translate their data into the SDP and GTFS before being loaded into the NY511 Trip Planner.
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