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schema

The goal of this repo is to provide a shared, comprehensive and, eventually, authoritative set of categories and datasets to map existing and planned infrastructure for active travel planning. Eventually, the intention is for this repo to also contain associated tools and code/documentation to make schemas defining active travel datasets useful for everyone wanting to map active travel infrastructure in a consistent way that is friendly and as useful as possible for people using the data.

Introduction

Database schemas define the fields contained within datasets and the values that are allowed. They are often visualised in database diagrams.

Advantages of well-designed and used schemas include:

  • Consistency between different users (local authorities, researchers, consultancies, other users)
  • Supporting people generating new plans to think about the data they may need to collect
  • Future-proofness: an evolving schema with empty fields that may become useful encourages datasets to be kept up-to-date

Just like software used to process data, data formats, and the underlying schemas that define them, should evolve over time.

Versioning the schema will ensure backwards compatibility and encourage innovation.

Existing active travel infrastructure schemas

TfL’s Cycling Infrastructure Database (CID)

The CID contains detailed data on London’s cycle infrastructure, divided into the following tables (see the example_data folder for examples):

Table Geometry Rows Columns Names
Advanced Stop Line Line 3775 12 FEATURE_ID, SVDATE, ASL_FDR, ASL_FDRLFT, ASL_FDCENT, ASL_FDRIGH, ASL_SHARED, ASL_COLOUR, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Crossing Line 1687 11 FEATURE_ID, SVDATE, CRS_SIGNAL, CRS_SEGREG, CRS_CYGAP, CRS_PEDEST, CRS_LEVEL, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Cycle lane/track Line 24976 23 FEATURE_ID, SVDATE, CLT_CARR, CLT_SEGREG, CLT_STEPP, CLT_PARSEG, CLT_SHARED, CLT_MANDAT, CLT_ADVIS, CLT_PRIORI, CLT_CONTRA, CLT_BIDIRE, CLT_CBYPAS, CLT_BBYPAS, CLT_PARKR, CLT_WATERR, CLT_PTIME, CLT_ACCESS, CLT_COLOUR, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Restricted Route Line 1378 11 FEATURE_ID, SVDATE, RES_PEDEST, RES_BRIDGE, RES_TUNNEL, RES_STEPS, RES_LIFT, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Cycle Parking Point 23758 22 FEATURE_ID, SVDATE, PRK_CARR, PRK_COVER, PRK_SECURE, PRK_LOCKER, PRK_SHEFF, PRK_MSTAND, PRK_PSTAND, PRK_HOOP, PRK_POST, PRK_BUTERF, PRK_WHEEL, PRK_HANGAR, PRK_TIER, PRK_OTHER, PRK_PROVIS, PRK_CPT, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Restricted Point Point 23758 22 FEATURE_ID, SVDATE, PRK_CARR, PRK_COVER, PRK_SECURE, PRK_LOCKER, PRK_SHEFF, PRK_MSTAND, PRK_PSTAND, PRK_HOOP, PRK_POST, PRK_BUTERF, PRK_WHEEL, PRK_HANGAR, PRK_TIER, PRK_OTHER, PRK_PROVIS, PRK_CPT, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Signage Point 118834 37 FEATURE_ID, SVDATE, SS_ROAD, SS_PATCH, SS_FACING, SS_NOCYC, SS_NOVEH, SS_CIRC, SS_EXEMPT, SS_NOLEFT, SS_NORIGH, SS_LEFT, SS_RIGHT, SS_NOEXCE, SS_DISMOU, SS_END, SS_CYCSMB, SS_PEDSMB, SS_BUSSMB, SS_SMB, SS_LNSIGN, SS_ARROW, SS_NRCOL, SS_NCN, SS_LCN, SS_SUPERH, SS_QUIETW, SS_GREENW, SS_ROUTEN, SS_DESTN, SS_ACCESS, SS_NAME, SS_COLOUR, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Signal Point 443 11 FEATURE_ID, SVDATE, SIG_HEAD, SIG_SEPARA, SIG_EARLY, SIG_TWOSTG, SIG_GATE, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry
Traffic Calming Point 58565 14 FEATURE_ID, SVDATE, TRF_RAISED, TRF_ENTRY, TRF_CUSHI, TRF_HUMP, TRF_SINUSO, TRF_BARIER, TRF_NAROW, TRF_CALM, BOROUGH, PHOTO1_URL, PHOTO2_URL, geometry

The CID’s data has a rather verbose schema in which many attributes such as cycleway type are converted into a series of boolean (TRUE/FALSE) expressions. Converted into a dataset in the Arrow format, the column names and associated data types, example values, asset types and labels are as follows, for the Cycle lane/track table, for example:

Many of the columns in the schema outlined above have been replaced in schemas in this repo by ‘type’ keys that accept values including Advisory lane, Full separation and Stepped separation for motor traffic. See the cid example, TfL’s schema document, the repo https://github.com/PublicHealthDataGeek/CycleInfraLnd/ and associated paper (Tait et al., 2022) for further details on the CID.

Ordnance Survey Schemas

TBC.

OSM

TBC.

The OpenInfra project

TBC.