Ottawa City organised a hack fest around open data. You've probably seen some of my posts as I scrabbled to at least get them to look at alternatives to Google. The ability to display road names in both languages turned out to be something that was commented favourably on. It was done using an unreleased version of Maperitive but there should be an easier way. The ability to select what is displayed is glossed over but some improvement in ease of use might be useful.
Anyway Sam thought others might be interested and have some ideas. Cheerio John ---------- Forwarded message ---------- Background These thoughts arose from the Ottawa Opendata Hackfest April 24th 2010 and are based on my thirty five years of computer systems. I tend to look for possible problems and implications early on when they are cheaper to address and to see if I can find ways to make techniques available to a wider audience. The major theme here seemed to be about combining OpenData and maps and could the city gain benefit from offering a $50,000 prize. Requirements There are a number of groups with different ideas and requirements for combining OpenData and GIS systems. These maybe different from the clients or expected end users. If we start with the group I saw making a presentation then I think they would like something simple to program. I'm making this assumption based on the predominance of Mac lap tops and I suspect the use of Google API and the drawing functions over the map which is currently easier in Google. Also their presentation of a drinking fountain application which overlaid drinking fountains on top of a Google map. If we look at the city councilors they would like something to promote Ottawa or be Ottawa specific, this was stated at the informatics subcommittee I attended where OpenData was raised. There are also background requirements to lower 311 costs, improve response times, improve road safety, balance improved bilingual services and cost and the other 101 things the city is responsible for. Ottawa Businesses like maps that show where they are. The success of Google Maps show this. A search for "florist, K1E3P6, Canada" in both Google Maps and OpenStreetMap (OSM) turns up "Select Blooms, 1675, Tenth Line Road, K1E3P6, Ontario, " the only difference is that Google displays the phone number whilst if you click on the small+ sign on the right OSM allows you to drill down to the associated tags, thus giving the phone and fax numbers, web site address, and other information such as hours of opening for the point of interest (POI). OSM doesn't charge businesses but does accept donations. One difficulty with electronic maps is sometimes there is too much data to display clearly. OSM historically has had close connections with cyclists, so one option on the + sign is to display the cycling routes or lanes such as Merkley. This is done by the use of rules which control which POIs such as drinking fountains or cycle paths are displayed. The use of the + sign once learnt does give a consistent way to access tags. So a park could have a tag that says no dogs and this can be determined by inspecting the tags. End users or Ottawa citizens would like something stable, reliable, consistent, easy to find, useful, easy to use and they also think in terms of cost. Can I click on the library or supermarket to see the hours of opening? Will domains such as fixmystreet.ca be available next year if someone forgets to renew the domain name? Why isn't the interface consistent on these different web sites? Do I trust this web site enough to run scripts? Can I trust it anyway? Will I remember that fixmystreet.caisn't just to report potholes? Why doesn't this web site accept my postal code? Can we involve citizens in some way by giving them the ability to contribute? ie to be able to enter points of interest that interest them in the underlying map. One end user interviewed liked the idea that he could click on a street lamp to report it not working. He wasn't impressed by the idea that an email going to 311 to be passed on to the relevant department could take four working days to be read by 311 before being passed on. This is a more complex type application that needs to pick up data from the map and forward it to the city. Another couldn't see why they had to have an internet connection to view a map. Wireless Internet connections cost money, and if they were quite happy using a printed map that was three years out of date why did they suddenly require up to the moment information. The comment was buildings tend not to go for walks in the middle of the day. Thinking about it the data in these maps is usually imported from other sources and can be several years out of date. How much value is the requirement for Internet access adding? One of my favourite comments was why do I need a computer at all? Can't you just give me a bit of paper with the specific information on? So much easier to carry around. This one is quite an interesting idea, printing on paper is higher resolution than a computer screen, it's also much cheaper and doesn't need an internet connection. I didn't have a lap top with wireless internet access available for the Hackfest but did leave a number of small printed maps at the sign in desk showing the location of the nearest Second Cup coffee shop. The City Hall 111 coffee house being closed on Saturdays. A spin off would be to provide something that could be displayed on an ebook or GPS device. Tourists would find a tailored map perhaps showing the Points of Interest for the Jazz festival, or the Tulip festival useful. Wheel chair users have specific needs such as ease of access, some have incomes that prohibit the purchase of wireless enabled internet devices can we find ways to not exclude them at low cost? An option of paper maps that show information of specific interest to them would be valuable. Are we using any public funds or providing service from the city's web site? If so then addressing the needs of Francophones should be considered. Google Maps is available in French but the roads are shown with their English names. One Francophone interviewed showed great interest in the idea of the French street names being displayed. The two .jpgs below show the same OSM map data with English and French names. Only a couple of roads have their French names tagged. http://groups.google.com/group/maperitive/web/French.jpg http://groups.google.com/group/maperitive/web/English.jpg This technique can be extended to all names so City assets could display either a French or English name depending on the configuration and if the information had been entered. Within the city departments there are a variety of needs, for example two years ago the City forester mentioned it would be very nice to map the trees in Ottawa but they didn't have the funds to do this. There are a number of organisations who have the members who could volunteers to do this but not the technical expertise. Can we make it easier? A member of the planning department mentioned they would like a map that was copyright free. Different city departments seem to have different ideas about what data is available to the city. For example the footpath by the side of 717 Morewood is snow ploughed by the city in winter but doesn't seem to be considered as an option by OC Trip Planner. The Paramedic Public Access Defibrillator Program probably would like a map showing the automated external defibrillator (AED) devices but like the locations under their control. Finally computer programs and people like consistent names for things such as phone should be labeled phone in some places and not telephone in others. The OSM data is available for correction in XML format and to get better consistency so the tag data can be processed programmatically more easily there is a need to standardize terms etc. As I went through these requirements it became apparent that some were quite technically complicated but there was a real demand and it would be nice to meet these demands if possible. GIS & database Background Geographic Information Systems (GIS) basically have points described with latitude and longitude on a map and tags to describe the data. Two or more points can be linked to describe a road with the tag applied to the link. This is very similar to a database and the information is searchable. For example "florist, K1E3P6, Canada" brings up a point of interest (POI) with tags such as "name=Select Blooms, Florist." In general terms the more data we have in a single database the more complex the search can be. If we link a map to a separate source containing the locations of drinking fountains that works but if we want to create more complex queries such as a playground with a drinking fountain within 200 meters of a cake shop it is simpler to build the query if all the data is in a single collection of data. Note all the data is held in a database and we create the visible map by extracting the relevant data and rendering it. In the case of the Google apps it is a two stage process with Google rendering the underlining map and the app creating an overlay. There are technical issues about how much data can be displayed at once and which data should be on top. For example a name should be layered above a forest area in order for it to be visible. What can we do simply today? If we start with an imaginary application we want low cost but a good payback. A car can carry a GPS device that can record tracks. If one had an application that could read the tracks and confirm the car hadn't gone above the speed limit then we might feel more comfortable about letting a teenager borrow the car since we can reasonably expect fewer and less serious accidents at lower speeds. A good quality GPS device with tracing would cost $150 but gives us some of the benefits of a GPS speed limiter at lower cost. www.carsguide.com.au/site/news-and-reviews/car-news/gps_speed_limiters_in_action . By making the speed limit information available in this way GPS speed limiters can make use of it and make our roads safer. In general Google based solutions have a number of drawbacks, lack of French names, we can't easily add tags and data to the Google data base, privacy issues, it doesn't include footpaths and most businesses and organisations have to pay to be included. They are US based so not covered by Canadian privacy legislation, data can be supplied to the CIA, who have previously used the possession of a Casio watch as proof of being a terrorist. Even searches relating to drinking fountains will be collated, perhaps to point out a nearby cafe or for some other reason. "What exactly is Google up to? That's the question some may ask based on recent news that the search giant's Street View cars are scanning private WLAN networks. Although there's no word if Google is conducting its invasion of privacy here in the States, German officials have discovered that the automobiles are not only scanning consumer-based networks, but is possibly obtaining users' unique Mac addresses in the process." www.tomsguide.com/us/Google-Mac-Address-Wi-Fi,news-6574.htm "Google CEO Eric Schmidt has said that Internet users shouldn't worry about privacy unless they have something to hide." If these issues are not addressed they could come back later on in the project. Note there is a subtle difference between me choosing to use a Google Map and finding myself forced to use one because of an application. On the positive side it does have a seductive API and it's easy to add a small application. From the city's point of view if its OpenData and Google chooses to use it then it doesn't have any responsibility for a French language version. Google has developed some useful interfaces such as the Google Transit Feed Specification (GTFS) which has now become the General Transit Feed Specification and is becoming a more generally used interface standard. Ottawa GTFS data appears to be available on the web although currently little is known about the source or how this information is licensed. With any Open Data licensing of the data must be considered. Ideally the data license should align with accepted practice or people will have trouble understanding the license. The creativecommons.org 3.0 is recommended, creativecommons.org/licenses/by-sa/3.0/ and creativecommons.org/licenses/by-sa/3.0/legalcode since this is well understood. Would we be any better off with a solution based on OSM? We can add tags with the speed limit to OSM. The data is incomplete in that some footpaths are mapped, some aren't. Some coffee shops are in, others aren't. The data can be added to or modified by anyone, including computer savvy teenagers so it isn't reliable enough to see if your teenager has been keeping to the speed limits. However it does mean volunteers can add trees to the database. However what OSM does have is an environment. So tested routines already exist for importing CANVEC data and from other sources including GTFS. It has different rendering options both web based and standalone options. The information can be displayed on the web, or off line, or on a GPS device such as a Garmin, formatted for an ebook, or even printed with a variety of options. Customised town guides have been created. Other cities have created wheel chair friendly routes. This modular approach means it is open to new applications. So can we build on the OSM standard interfaces and routines? What some organisations have done is set up their own OSM server. This allows control over the data so we know we can trust the speed limits and AED locations for example. The low cost way of using the speed limit data is to compare a trace against a map. Commercial GPS speed limiters are available but need a map with the speed limits as infrastructure. If Ottawa was to come up with a secure map based on open standards with speed limit tags it is highly likely that other cites would follow. OSM also opens the door to use many other applications such as Maperitive which is a standalone program that can display OSM format data without being connected to the Internet. It also takes the load off a web server and improves response time for those on dial up. It is possible to repoint Google applications so they run over OSM but using Openlayers wiki.openstreetmap.org/wiki/OpenLayers is preferred. It is also possible to do a "Mash up" using JavaScript in about the same time as using the Google approach but you need some experience in JavaScript. What GIS resources are available in Ottawa? Ottawa is home to a considerable expertise in GIS. For example Open GIS Consortium (OGC) has a chapter in Ottawa. They know about things such as OpenGIS Web Map Service (WMS) which can use OSM as a data source. Natural Resources Canada has a lot of expertise in GIS systems. Carlton University has courses that combine Mapping, GIS, mathematics and computer programming. The city itself creates maps and internally has expertise. It might well be worthwhile consulting internally in the planning department at least to see which direction the city should be going. What can we expect as a response to our $50,000 prize? Realistically applications process data. Ottawa's data really isn't that much different to anyone else's data. For example all libraries have opening times but do we really need an application to display these specifically for the Ottawa ones when these can be displayed directly in OSM anyway. If an application displays drinking fountain information on a map for Vancouver it doesn't take much effort to modify the code to display the same information for Ottawa and my expectation is that many of the entries will be along the same lines. Small applications that have been modified from previous work. I doubt if many will be original and given the amount of effort that needs to go into testing, this approach produces robust applications fairly quickly. This may not be the city council's hope or intention. More complex programming takes time to design and integrate with existing systems. We might be lucky and have someone come up with a way to make OSM rules more user friendly to display florists or drinking fountains. Recommendations If the city would like to tag the streets with speed limit data or have maps with AED device locations under its control then the recommendation would be for the city to run its own OSM format server importing the road data directly either from the OSM servers or from CANVEC using existing tested import scripts which I think are available. Speed Limit tags and AED locations can be added to this data. Then I'd populate the rest of the map from the existing OSM for Ottawa after filtering out the road data. This approach would allow people to add information about businesses for example into OSM knowing that it would be imported into the city's version when the map was renewed. Note that Microsoft has a very useful tool called Biztalk which can be used to combine spreadsheets, structure text files, databases etc. with XML to make the process of generating maps easier but isn't normally thought of as a GIS tool. If the city decides it doesn't need that level of control then the recommended approach would be to simply release as much data as possible under the creativecommons.org 3.0 license and take a hands off approach to what happens next. Hopefully OSM will be augmented with the city's data by releasing the data under license so that information about the city services such as libraries opening hours, web sites etc. can be merged in using database techniques of a using a matching key then copying the opening hour information etc over to the tags. Example www.openstreetmap.org/?lat=45.47062&lon=-75.49196&zoom=17&layers=B000FTT and click on the library building to see the web link and other information. On the Google side just releasing the data would mean the city wouldn't have any responsibility on whether the end users could find the appropriate web site for their information request, nor if the web sites rejected a valid post code as I've seen one do, nor would they have any responsibility to see that clients weren't infected as a result of visiting an insecure web site. Finally thank you to the many people who have been patient enough to answer questions or with whom a conversation triggered off a thought. I must confess I hadn't come across the Google API before and I learnt quite a bit about OSM's capabilities compiling this report. Cheerio John
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