University of Cambridge - OpenStreetMap Wiki

University of Cambridge - OpenStreetMap Wiki
University of Cambridge
From OpenStreetMap Wiki
(Redirected from
Cambridge/University of Cambridge
Jump to navigation
Jump to search
Cambridge University
uses OpenStreetMap as the basis for its university maps
both on paper and on
. Known as
'Project Drake'
, it was completed in June 2012 after which data is being updated as it changes, and the map is being brought into production. For more information about the project, please contact
David Earl
The University commissioned detailed property surveys and has contributed the data back to OSM. However there is additional non-geographical information which it is not appropriate to store in OSM yet which needs connecting to the OSM data. Additionally in order to provide a good service, there needs to be consistency in the OSM data.
This page summarises how the University is being mapped. On the whole, this follows common conventions in OSM, but introduces a few new tags (occupier with respect to buildings, for example) and uses others in novel contexts (ref on buildings and building entrances, for example).
Contents
Update March 2020 (and organised editing)
Satellite imagery
University sites
Buildings
Building entrances
Archways and colonnades
Roads and paths
Parking
Landuse
10
Non-university references
Update March 2020 (and organised editing)
Since the original survey in 2011-2012, piecemeal changes have been made (rate of change within the University is high), but starting March 2020 we are undertaking a more systematic review and update.
University of Cambridge University Information Systems (UIS) funds the maintenance of map data in the University estate.
The project long pre-dated
organised editing guidelines
, but with this "reboot" we're offering the following :
change set tag: #UCamMap
co-ordinator: Chris Garrett (christopher.garrett@uis.cam.ac.uk)
other regular participants: [osm:user/davidearl David Earl] (contractor); [osm:user/BarnabasBaggs Barnabas Baggs] (UIS); [osm:user/Ben Harris Ben Harris] (UIS, map service manager)
Satellite imagery
Note that the survey is being carried out on the ground using distance measuring equipment. While much more accurate than GPS and satellite imagery in principle, accumulated errors, and fitting to existing data, mean that in the end it has unit metre accuracies of the same
order achievable with GPS in ideal conditions. However, conditions especially in the dense central properties are far from ideal. In many locations small courts surrounded by high buildings mean that there is no practical GPS signal at all.
Satellite imagery might seem ideal - Bing coverage is excellent. However, it is often not clear from the air where something is a roof at a different level or a ground feature (for example, previously the University Library had a large chunk removed erroneously from its west wall because of satellite misinterpretation). More importantly, many of the satellite images for the city are oblique (the sides of tall buildings are visible) and tiles are misaligned. GPS reveals other unexpected displacements. The result is that satellite imagery, while very useful, cannot be trusted to any greater extent than other sources.
Therefore, please do not be tempted to realign buildings with their aerial imagery. The relationships and distances between buildings has been carefully worked out on the ground.
That is not to say satellite imagery isn't useful. Some parts of buildings are not accessible on the ground. Other times subtle non-orthogonality of buildings and angles between buildings are hard to measure on the ground.
University sites
The University of Cambridge is not a campus university. Its properties are spread across and beyond the city. It has both deep and tenuous links with institutions which are not actually part of the University (Addenbrooke's Hospital, for example, whose buildings share a common
biomedical campus with many institutions which are part of the University). For various purposes, including navigation, some properties are grouped by the University into 'sites' which have distinct boundaries. Academic departments and other institutions of the University are often housed in multiple buildings across multiple sites.
Furthermore, the University is famously also comprised of 31 administratively and financially independent colleges. Geographically, the colleges can be considered similarly to sites: they comprise groups of buildings enclosed by a well-defined boundary. However, colleges also have 'outliers': additional properties separate from the main college site (especially residences and sports facilities, but also some academic). Typically these are 'sites' of their own (for example Trinity College's Burrell's Field or 'Clare Colony').
Boundaries can almost always be determined from a combination of bounding streets and boundary walls, satellite observation and information provided by permission of the University.
Site and college boundaries should be closed ways (occasionally multi-polygons) and should be tagged:
operator
University of Cambridge
name
Whichever Site (University of Cambridge)
or
operator
Whichever College (University of Cambridge)
name
Whichever College (University of Cambridge)
as appropriate, and
amenity
university
The site would also have a reference letter, for example:
ref
(which is the New Museums Site). Colleges are identified with their subdomain [or id - TBD] in upper case, e.g.
ref
DOW
for Downing College. Secondary college sites have an slash-separated suffix, hence
ref
TRIN/BURR
for Trinity’s Burrell’s Fields site.
Where there is a boundary wall, this should be represented as a separate co-incident way marked
barrier
wall
(The unlisted tag barrier=railing is also used when appropriate, as is barrier=hedge).
Entrances into the site or college are usually gates in the boundary, hence a node
barrier
gate
barrier
lift_gate
or where there is no physical barrier, then
barrier
entrance
These will also be assigned references (related to the site).
ref
E-A
and a type
entrance
main_entrance|secondary_entrance|goods|parking|private
Additionally, specify
access
private
Site/college entrances specified with barrier are assumed accessible to vehicles, on foot or by bicycle unless explicitly stated otherwise with
vehicle
no
bicycle
no
foot
no
Buildings
Take care with orthogonality: renderings may be made at a much larger scale (zoom level) than is typical on the OSM site.
In addition to
building
university
or whatever, University buildings should be tagged
operator
University of Cambridge
or
operator
Whichever College (University of Cambridge)
Name should be the name of the building not the department(s) or institution(s) occupying it. Hence
name
Veterinary Anatomy Building
(not
name
Department of Physiology, Development & Neuroscience
) except where the building is anonymous, identified only by its occupier.
The occupier should be given using the novel tag 'occupier', hence
occupier
Department of Physiology, Development & Neuroscience
(where there is more than one separate with semicolons; more than 256 characters TBA). Where occupier is the same as name, it should be duplicated. name will also often be duplicated into
addr:housename
=*
Note in particular that Porters' Lodges and site security huts and offices should be tagged
occupier
porters
occupier
security
respectively (n.b. lower case). This will allow these to be marked distinctively on maps. Note: where this is part of a larger building, mark the entrance to the porters' lodge etc instead (see below)
ref
=*
is used to identify the building by its internal University designation. These are of the form 'Snnn' where S is the site code (e.g. 'M' for New Museums Site) and nnn is a three digit number, and it is these references which link the map data to the University
internal database. For example,
ref
M031
References are sometimes displayed on plans at the site entrance. However, at one time these were references such as M10A, M10B etc and these have since been renumbered. Plans may also omit leading zeros, but these should be included in the ref tag. Hence for example, ref=M031 Where renumbering has occurred, the superseded reference may be given as
alt_ref
M10A
Sometimes, the same University reference is applied to several buildings, usually joined in some way (e.g. a terrace or linked by a bridge) because they function as a whole. However for geographical and labelling purposes it can be useful for these to be made distinct. This is done by appending a period and number to the main reference, allocated by the University Computing Service, e.g.
ref
M031.1
(Consider, for example, the 'Inglis' and 'Inglis A' buildings in the Department of Engineering, separately named and very distinct structures, but referenced the same in the main referencing scheme).
Conversely the same physical building may be split with separate references, but that's fine.
Colleges are not included in any existing central system, but are having building references assigned for this project: the college subdomain (or ID - TBD) (upper case, as above) followed by three digits, e.g.
ref
DOW010
It may be appropriate to include
addr
=*
:... tags, but don't assume the street name is the nearest street! Postcodes and streets are usually available in internal University documentation. Also note that the postal address for an institution is not necessarily the same as the
building it occupies.
Where institutions occupy some or all of terraces of buildings, it may not be clear where the divisions are. In this case, the whole terrace could be shown as a university building and then nodes used for entrances and the building itself within the terrace outline. This will allow a sensible spot on the map to be marked while not being overly prescriptive about the inaccessible arrangement of internal walls.
Building entrances
It is an important feature of the University map that building entrances are marked and referenced. The conventional way to do this is to include a node tagged
entrance
something
where
something
is a type of entrance:
entrance
main_entrance|secondary_entrance|staff|goods|fire_exit|private|porters|security
or just '
entrance
yes
' for insignificant ones (but these will not appear in the University's index).
Significant entrances are also tagged with a reference, e.g.
ref
M031-A
ref
DOW010-A
The reference is generated by the University Computing Service, but is typically related to the building reference (though entrances occasionally more than one building). However, note that college residence staircases (residence doors) follow the convention
ref
DOW--C
example
(college subdomain, dash, dash, staircase identifier - sometimes more than one letter, as in PEM--LL; note separate sites may re-se letters, so CAI--BB and CAI/HARVEY--BB). Where two or more staircases share an entrance, separate the letters with a comma, e.g.
ref
DOW--U,V
Such entrances would also have names
name
name
U & V
Many (most, perhaps, and even in some new buildings) entrances have steps leading up to them (see below), so it is important to identify those which are wheelchair accessible (though there is no point designating wheelchair access if there is only a set of stairs inside
the building).
wheelchair
yes
Sometimes entrances served by steps also have adjacent external wheelchair lifts. Mark such with a node tagged
amenity
wheelchair_lift
Many buildings have external spiral staircases. Sometimes these are just fire escapes, but often they are building accesses too. In the spirit of highway=steps, tag a node as
highway
spiral_staircase
(Note: previously entrances were indicated using
building
entrance
, but this has since been deprecated by OSM in favour of just the
entrance
staircase
tag).
Archways and colonnades
It is very common to find doorways (and porters' lodges especially) opening off wide, long, geographically significant archways and gateways, or off colonnades within a building footprint. While an isolated node for the building entrance is possible, it doesn't give us direction or building relationship. Therefore, this particularly common idiom is being represented as
area:highway
footway
(or service etc)
covered
arcade
Typically there is a massive gate at one end, so there will be a
barrier
gate
with a reference, an entrance type and maybe a name (as above) at the junction between the area and the path or road leading to the gate. For example,
the gate to Clare College
(note the main gate, and the porters' lodge and staircase B leading off the tunnel).
Then doors off the tunnel are simply
building
entrance
with all the ancillary tags as above.
Colonnades are similar: tunnels with a long edge coincident with a building. For example,
under the Forbes Mellon library at Clare College's Memorial Court site
Roads and paths
All internal highways are
access
private
Usually, vehicle accessible roads will be
highway
service
and rarely have names.
Many sites are hard-surfaced between buildings, and where this is more than just a vehicle corridor, it should be represented as a polygonal area
highway
service
area
yes
(see also Parking below)
highway
footway
or possibly
highway
pedestrian
and often qualified by
bicycle
yes
for non motor routes. Generally only use
highway
cycleway
where a route is specifically marked for cycling (such as the corridor down the western side of the Sidgwick Site for example).
As well as gates marking the entrances to sites, there are often barriers restricting vehicle movements. For example,
barrier
lift_gate
is well defined already. Use
barrier
rising_kerb
for barriers which rise out of the ground (e.g. in the Old Addenbrooke’s site).
Numerous locations around the University have raised or sunken piazzas or ornamental facades and porticoes accessible by a wide flight of steps, often on three sides or in a semi circle.
Ordinary steps are
highway
steps
step_count
incline
up
(with 'up' in the direction of the way). There isn't a very satisfactory representation for very wide steps. For example, the Sidgwick site has steps surrounding almost the whole central area, the largest of which has only four steps but is about 60m wide. Using a single way as per ordinary steps but with
width
has been suggested, but this is hard to get angled exactly right and, while not advocating tagging for rendering, it looks unsatisfactory on OSM.
Therefore, so far I have used multiple parallel ways each marked as steps. In due course, I am inclined to link these with a relation.
Steps are often accompanied by a wheelchair accessible ramp (sometimes also provided for and used by cyclists). This follows current proposals, namely:
highway
access_ramp
(Unfortunately this does not render at all on OSM currently, but will do so on University maps.)
Parking
Parking spaces simply "on street" in the general vehicle network are not being marked routinely, except for disabled spaces:
amenity
parking
parking
disabled
capacity:disabled
Where a proper car park is marked, use
highway
service
service
parking_aisle
for its internal accesses, and always designate
access
private
operator
=*
(as above)
Cycle parking is being collected:
amenity
bicycle_parking
bicycle_parking
=*
=sheffield|t|v|high_capacity (ie. type of stands)
capacity
(number of cycles not number of stands)
operator
=*
access
private
covered
yes
(if it is)
There are a few motorbike spaces around:
amenity
parking
parking
motorcycle
capacity
and other tags as above.
Landuse
Colleges especially are rich in greenery.
Use
landuse
grass
areas for lawns. Ideally use separate areas for separate lawns rather than a single area with a path running across it, especially where the paths are the typical wide gravel variety: these will be used at much higher scales than the usual OSM website, so while not essential it gives a better pictorial outcome.
Only use
leisure
garden
where the feature is specifically laid out as a garden. Often such gardens have names (Fellows' Garden for example).
leisure
garden
name
Fellow's Garden
College "courts" are often used to subdivide parts of a college. In some cases the court might actually be the name of a building, it is more often applied to the space around which buildings are ranged, possibly with somewhat ill-defined boundaries. The same building may face more than one court. In some cases, all the entrances face into one court so "staircase A" may be said to belong to "West Court". In others the same "staircase" (effectively, block of rooms) may have doors onto multiple courts. The courtyard void may be identified without needing to precisely define its boundaries with a novel value for the landuse tag:
landuse
college_court
name
West Court
operator
=*
(it is also fortuitiously helpful that Mapnik renders such names)
Colleges may also have woodland in their grounds (more than just a few trees in a row! - which can be individually shown as
natural
tree
if you want). Woodland is a closed way tagged
natural
wood
Follow the OSM model for sports pitches and grounds.
Non-university references
The University map indexes a number of sites and buildings around the City which aren't run by the University. This is a rather eclectic collection. As such it is not possible to select based on common characteristics. Previously they were identified individually in the map by a combination of name and/or operator. However, this is proving inadequate and therefore such properties are now identified with
ref:university_of_cambridge
yes
or
ref:university_of_cambridge
reference
where the reference follows the University reference pattern using a "site" EXT, or where the building is part of the University Estate but let or used by a non-University entity, the usual University estate reference. A reference is only necessary where the item is to have an index entry with additional information in the University's index, so that it can be linked to it.
Retrieved from "
Category
United Kingdom
Navigation menu