Page 1 of 16 - European Commission · 2016-09-28 · Access to Public Data for Digital Road Maps" 29 March 2011 - Brussels Today I am going to share the TfL experience of sharing

Access to Public Data for Digital Road Maps" 29 March 2011 - Brussels

Today I am going to share the TfL experience of sharing transport

data with third parties. TfL does not get involved with providing

road geometry data, and only supplies limited attribute data. But TfL

does share much of its business data, which depends on high

quality spatial attribution to be of any use to the organisations who

use it.

The political environment is changing and this is putting increasing

pressure on public sector bodies to be more open with their

business data, which if offering both challenges and opportunities.

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Way to Go was the new Mayor of London’s vision. He set the

challenge of improving TfL’s information offering to London’s

travelling public.

The Smoothing Traffic Flow strategy highlights the improvement to

road user information as a critical factor in the strategy.

TfL had always been good at providing public travel information, but

our services to road users were very limited.

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In 2010, the Mayor has set out the Transport Strategy, outlining the

strategic context for how we deliver services to road users and the

priorities for TfL.

The Strategy has some high level goals, it lays down specific

challenges to TfL and then proposes outputs to reach the desired

outcomes. Improved traveller information is a theme that runs all the

way through the document and the challenge to TfL is to do this

effectively, at least cost.

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And then the Mayor of London released his data store in February

2010, to free London’s public data for use by everyone. This was

after a sustained campaign to Government to “Free Public Data”

(based on the fact that the general public pay the UK public sector to

collect the data in the first place).

This Policy change actually presented some useful opportunities to

TfL to meet the wider obligations of Smoothing Traffic Flow. TfL does

not have an existing customer base for road information. We do not

have many existing channels to use to able to share more traffic

information, so by publishing the raw data, free, third party

commercial organisations can now take it and add it into their existing

products and services (enabling TfL to reach a much wider audience)

Variety of transport data is made available to third parties through this

initiative; live traffic disruptions, real-time camera images, live

roadside message boards, live tube status, timetables, coach parking

locations, Cycle hire docking station locations, bus stop locations.

At present, around 70 organisations have subscribed to the traffic /

road data feeds.

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There are a number of challenges for TfL in meeting our obligations

under both the Mayor’s Transport Strategy and the London Data Store

policy.

Is our operational data available to the right quality and standards?

Is our spatial data in the right format? Can we release it or are there

license restrictions? What spatial attribution should we use?

How do we offer a resilient service, when it is free? How do we manage

the consumption of our business data by an ever-growing developer

community? How do we manage changes and updates?

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Operational data is collected as part of operations and used for

internal purposes, to manage London’s road network. It is not

necessarily fit to be shared outside the business. And once it is

shared with third parties, the limitations are highlighted and third

parties have high expectations on TfL to improve the quality and

provide more and more data.

For example, the camera image data is derived from the existing

network of operational CCTV network. We publish images from

only about 15% of the total cameras. This is creating challenges

with the expectations of developers and their customers.

CLICK>>>>

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The camera images are updated once every 3-5 minutes, but if a

camera is being used by TfL staff, then the refresh rate is less

frequent and, if after 20 minutes, the camera is still in use for

operations, a default black screen is displayed. TfL has had lots of

feedback from developers and customers asking for a higher

number of camera images, refreshed at a more frequent rate,

dedicated to traffic information only, and ideally, providing live

streaming video. It is not cost effective to change the current system

right now, so users have to accept the limitations.

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e.g. Traffic disruption data – TfL has never applied any of the

current common standards (such as Datex2, SIRI, TMC, UTMC

etc). The data is captured as an operational log and therefore

includes lots of the useful data as free text (and therefore NOT

machine readable). Much of the location information is also free

text and the only meaningful spatial data is a single easting,

northing coordinate.

We have also realised that users have a variety of requirements,

depending on how they intend to use the data...

Data for routing and navigation is different to data displayed on a

web map, and different again when being used in a phone

app...format, missing attributes etc all become issues to be

addressed...

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This is TfL’s web map (www.tfl.gov.uk/trafficnews). The

disruptions are displayed against a single point coordinate, with

all the important spatial detail recorded as free text – which is

NOT machine readable. This approach is fine for viewing on a

web map, but not at all suitable for other purposes.

This event was a large scale public demonstration in central

London, which involved a significant number of road closures.

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The Met Police published the full detail, as a PDF map on their

web site. This is a totally different way to show the data and

perhaps more useful for those road users who may wish to

drive in London.

In order to get this amount of detail into a navigation device,

each road would need to be separately recorded as a closure,

which is a significantly different approach to TfL’s current data

capturing.

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This map shows an example of how TomTom display disruption

(journalistic data). TfL has been in discussion with TomTom to

understand how to improve TfL traffic disruption data.

Grey lines show road works – they use a start and end point,

rather than a single coordinate or a polygon.

(Red lines show delay data from their own HD Traffic engine)

By working with some of the consumers of our data, TfL is

starting to re-think how we capture the source data and how we

might share it more effectively. We are using TomTom and

others to inform our thinking and to advise us on how other

cities and countries format and share their dynamic data. This

is the only way for TfL to improve what we do.

Page 11 of 16


However, TfL does have another challenge when sharing our business

data.

UK Ordnance Survey Integrated Transport Network is TfL’s common

standard to which all our data is linked. Image shows the Transport for

London Road Network (red), the Olympic Route network (brown), the

congestion charge boundary (buff shading) and traffic signals (green

dots). We buy a license from the Ordnance Survey (OS) for the ITN

and the UK Mastermap layer. However, any data that is derived from

ITN (most of our linear and polygon data) can only be shared with

organisations who also have a suitable license with the OS.

We can publish points as easting / northing coordinates. ITN is

proprietary, based on TOIDs (topographic identifiers) which define the

centre line of the road network and Mastermap which defines the

geometry. In theory, we can publish TOIDs, but they are meaningless

to anyone who does not have the right license to be able to “de-code”

them.

This is limiting for TfL. For example, there is demand for the Olympic

Route Network and associated “measures” (attributes such as lane

restrictions, turning and movement restrictions etc), but as it is derived

from ITN, it can’t be published. TfL overcame the situation when we

started the Congestion Charging scheme, by allowing third parties to

access the data if they signed to confirm they had the correct OS

license.

A another example of this challenge is with our bus route data...

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Bus route data is a prime case. TfL is responsible for designating

and managing bus routes (contractors run the services, but TfL is

responsible for providing all the passenger information.

Unfortunately, TfL is not permitted to publish the geometry of the

bus route, because it is aligned to ITN. This image shows TfL’s

website (http://www.tfl.gov.uk/tfl/gettingaround/maps/buses/),

where the public can find information about bus routes, stops and

timetables. Because we use a Google map, we can show the

bus route line on it. We can, however, show the bus stops and

the order of the stops for each bus route, so this is also the raw

data that we publish through the London data store.

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The final challenge to the public sector on releasing any data is

the issue of resilience and governance.

Once third parties start to reply on public sector data (and their

customers rely on it too), what is our obligation in terms of faults,

support, SLAs etc? Whose reputation is impacted if the data is not

available? If TfL start to rely on third party commercial organisation

to reach our customers, should we not invest more to improve the

resilience of the data service?

How do we manage version controls and updates – particularly

when third parties are consuming public data into bespoke /

proprietary systems.

And how is the data attributed? TfL is very clear on how our data

can be referenced and what developers are permitted to do with

our logos. This helps to protect TfL from association with poor

quality and inappropriate applications. BUT also puts more of the

liability for data quality on the third party. It also limits the amount

of recognition that TfL gets for our data.

There has been a significant effort in defining appropriate terms

and conditions, which act as a coverall for all consumers of the

data. Some of the larger commercial organisations are not

satisfied with the TfL Ts&Cs, but TfL does not have the resources

to manage individual agreements with hundreds of individual

organisations.

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Page 1 of 16 - European Commission · 2016-09-28 · Access to Public Data for Digital Road Maps" 29 March 2011 - Brussels Today I am going to share the TfL experience of sharing