The State of Transit Routing

My brother called me a week ago and during the course of our conversation mentioned that he made the trek to the Miami Auto Show. He was complaining that he really wanted to take Tri-Rail (the commuter rail that runs along Florida’s South East coast) but it was just too hard to figure out the rest of the trip once he got off the train. “One web site for train schedules, another for buses, and another for a city map to tie it all together. It was just too much trouble to figure out, so I drove. I just want to go online and get directions just like I do for driving, but that tells me which train, which bus, etc.”

Coincidentally, later in the day I downloaded the iPhone 2.2 upgrade with the new walking and public transit directions. So far, at least where I live, it’s useless. The little bus icon just sits there grayed out, taunting me. I guess because SEPTA (our local transit authority for bus and regional rail) isn’t giving data to Google?

My brother hadn’t heard of Google Transit, but It turns out to have some coverage in Miami. Their coverage at this point seems to be transit authority centric and doesn’t seem to have great support for mixed mode or stuff that crosses transit system boundaries. I am curious though, is it being used? Let me know in the comments if you are using it to good effect.

Anyway, my brother’s call on the same day as the iPhone update piqued my interest in the current state of the art for mixed mode transit routing. After some mostly fruitless web searches for I reached out to Andrew Turner. I knew he’d know what was going on in. This is what he had to say:

Routing is definitely one of the emergent areas of technology in the next generation applications. So far, we’ve done a great job getting digital maps on the web, mobile locative devices, and comfortable users.

One problem for awhile has been the lack of data. You can have a great algorithm or concept, but without data it’s useless. Gathering this data has been prohibitively expensive – companies like NAVTEQ drive many of the roads they map for verification and additional data. Therefore if you wanted to buy road data from one of the vendors you had to have a large sum of money in the bank and know how you were going to monetize it. This stifled experimentation and creating niche applications.

Now that the data is becoming widely, and often freely, available innovation is happening at an increased pace.

For one example, consider the typical road navigation. The global OpenStreetMap project has always had topology (road connectivity), but the community now adding attribute data to ways such as number of lanes, stop lights, turn restrictions, speeds, and directionality. Anyone can download this data to use with a variety of tools such as pgRouting. As a result people are rethinking standard routing mechanisms that assume travel from A to B via the fastest, or shortest, route. What if a user wants to take the “greenest” route as determined by lowest total gas mileage, or the most scenic route based on community feedback.

An area that has strongly utilized this idea has been disaster response. Agencies and organizations deploy to areas with little on the ground data, or data that is now obsolete due to the disaster they’re responding. Destroyed bridges, flooded roads, new and temporary infrastructure are just some of the aspects that are lost with typical navigation systems. However, given the capability of responders to correct the data and instantly get new routes is vital. And these routes may need to be based on attributes different from typical engines – it’s not about the fastest, but which roads will handle a 5-ton water truck?

This scheme was deployed in the recent hurricane response in Haiti in conjunction with the UNJLC, CartOng, OpenStreetMap and OpenRouteService.

Beyond just simple, automotive routing, we can now incorporate multi-modal transit. With 50% of the world’s population now living in urban areas, the assumption that everyone is in a car is not valid. Instead people will be utilizing a mixture of cars, buses, subways, walking, and bicycling. This data is also being added to OpenStreetMap as well as other projects such as Bikely or EveryTrail. GraphServer is one routing engine that will incorporate these various modes and provide routes.

And we’re interfacing with all these engines using a variety of devices: laptop, PND (Personal Navigation Device), GPS units, mobile phones, and waymarking signs. PointAbout recently won an award in the Apps For Democracy for their DC Location Aware Realtime Alerts mobile application that displays the route to the nearest arriving metro.

What’s also interesting is the potential of these routing tools beyond actual specific individual routes. Taken in amalgamation the routing distances form a new topography of the space. Given a point in the city, how far can I travel in 20 minutes? in 40 minutes? for less than $1.75? This type of map is known as an isochrone. Tom Carden and MySociety developed London Travel Time Maps that allow users to highlight the spots in London given a range of house prices and travel times.

Despite these apparent benefits, there is a large hurdle. Like road data, there has been a lack of openly available transit data to power applications and services. Providers like NAVTEQ and open projects like OpenStreetMap are possible because the public roads are observable and measurable by any one. By contrast, the many, varied local transit agencies own and protect their routing data and are reluctant to share. Google Transit has made great strides in working with transit authorities to expose their information in the Google Transit Feed Specification – at least to Google. This does not mean the data has to be publicly shared, and in many cases this is exactly what has occured.

However, not even the allure of widely admired Google Transit can induce transit authorities to share their prized data. The Director of Customer Service of the Washington Metro Area Transit Authority (WMATA) plainly states that working with Google is “not in our best interest from a business perspective.”

Hopefully, this situation will change, first through forceful FOIA requests, but later through cooperation. One step in this direction have been TransitCamps. And Portland’s TriMet is a shining example with a Developer Resources page detailing data feeds and API’s.

These experimentations are just the beginning of what is being pushed in the space. Routing is one of those features that users may not realize they need until they have it and then they’ll find it indispensable. The ability for a person to customize their valuation of distance to assist in making complex decisions and searching is very powerful.

For more projects and tools, check out the OpenStreetMap routing page, Ideas in transit and the OGC’s OpenLS standards.

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  • ian

    I’m glad you made this post, but a bit disappointed it has such a narrow perspective. I like Andrew Turner lots, but to take him as the definitive source for all things transit-related is a *bit* of a reach.

    Urban Mapping has been doing a whole heck of a lot of work in this area, with some pieces announced. We have detailed data and schedule-related info for around 70 public transportation systems. This is mostly US-focused, but we’re rapidly expanding coverage in Europe.

    First response is to data. GTFS has been invaluable in raising awareness, but make no mistake, Google does little of the work in data. With the exception of NYC’s MTA, agencies provide data to Google in the prescribed format. Google collects this data, tests it, then dumps it into their routing engine/index and millions of people can enjoy. There are 70 or so agencies that participate in Google Transit, yet only 10 or so make the data available to anybody else. In fact, an agency cannot make selective disclosure and *must* make it available to all (but compelling one to do this may involve unnecessary time and expense).

    Because data is not made available to Google (or anybody else) does not mean data is not available. I spoke about this at the Where2.0 conference several years ago in my talk “How Open Is Open?” It means that companies have to actually do work to get it. Urban Mapping has a developed a massive inventory of spatial, attribute and schedule data, the vast majority of which we source the old fashioned way–on the ground research. Collecting, normalizing and maintaining this base of data is no easy task, especially when data at the detail of a subway entrance is required.

    But data is (relatively) useless on its own, so we’ve made a significant investment in the Graphserver project. Now *this* is compelling–an open source, super-fast engine with a small memory footprint that can ingest GTFS or whatever schedules you like. We’ve been testing this engine with customers and have performed multimodal (walking, driving, inter-agency) lickety-split. If you want to build applications, graphserver is *the* place to be (but don’t worry, UMI will also offer hosted solutions).

    Finally, a schedule is relatively useless unless a train (or bus, etc…) sticks to depart/arrive times. But they don’t…so updates/alerts/notifications become of paramount importance. Urban Mapping has also developed a method to poll and ingest the 1000s of incidents and associate them with the relevant IDs. This info is pushed out via a feed, so UMI data subscribers can rest assured their data is the freshest it can be.

    And there’s much much more going on. The advent of ITS has raised awareness (and federal $$) to upgrade, experiment and partner with industry in novel ways. UMI will be announcing some unique initiatives in the coming months, and others will also continue to push this along.

  • It’s great to see this area get some coverage. There’s been a welcome surge of effort in the area of transit apps, spurred on by new mobile platforms like iPhone and Android, as well as the increasing availability of GTFS data and realtime transit APIs–I track a lot of these projects on my Headway wiki. There’s also been a lot of interesting discussion of transit data and applications on the Transit Developers list.

    While it’s true that many agencies are unfortunately still very slow to give out their raw data to the public, it is happening–and when they it doesn’t happen fast enough, developers are working around the issue by rolling their own. Witness, the unofficial GTFS feeds on the GTFS Data Exchange, and Harper Reed’s CTA API, all of which have had iPhone apps built on top of them.

    Incidentally, I’m fairly involved in Google Transit (and the GTFS project), and I can tell you that it works fine across agency boundaries–the Bay Area, NYC, and Montreal are good examples, and you can even get a transit route from Zurich to Vienna on Google Maps. (But I’ll be the first to admit that Google doesn’t have all the answers, and there’s room for a lot more ideas in the market.)

  • I recently moved to Austin, TX after spending the last 4 years living in France and Germany, and have been unsurprisingly disappointed in the state of public transportation in the US. While there are many hurdles to widespread adoption of public transportation in the US, attitudes such as those taken by WMATA are exactly the opposite of what’s needed to improve the situation.

    Germans, as Americans, have a love for driving as evident by the amount of effort put into their automotive engineering and autobahn. Unlike in America, however, one can live in Germany without a car, relying solely on public transportation. I routinely used Stuttgart’s public transportation website,, to route between any two addresses and would get back times, changes, and prices across the regional train system, the street cars, the underground, and the bus system, including walking times. I could go to and book tickets to just about anywhere in Europe with the same level of completeness. This is just something that I haven’t experienced in the US.

    If individual municipalities don’t have the technical know-how or resources to put something together as useful as Google Transit, at least they should provide their data to someone else who is willing to do it. They should be doing everything in their power to make the system more accessible.

  • Hi, Stefan Knecht from United Maps – a german venture producing hyperlocal vector maps for mobile people outside of cars.

    Kudos to OSM, they certainly do a great job. The recently completed dataset of Hamburg is incredibly good. Nevertheless I wonder how OSM will perform in “flat world”, in rural areas outside of larger cities and how crowdsourcing will scale into less populated and geek-prone areas. Especially if it’s cold, wet and dark outside: good times for wikiesque setups, bad times for outdoor crowdsourcing.

    There seems to be a old world / new world clash developing from a cultural bias, reflected by the diffuse feedback from a silicon valley based VC we talked to recently. She said like “(…) pedestrian navigation? multimodal? What are you talking about …?”

    If you are caught walking on the street in California, police assumes that you’re either on the way or just did something evil or your car got stolen. People obviously don’t walk over there. But people do walk, ride bicycles and use mass transit options in Europe quite heavily and all year round. Unfortunately, there’s no standard, no overarching system, nothing to take for granted – every european region has its own logic.

    There’s more than 70 public transit authorities in Germany alone, I’d guess it’ll be more than 700 for Europe. Not something to be solved on a rainy weekend.

    Pledging for more openness is noble but beyond that, it’s hard work, research, data normalization and tedious research — much of what Urban Mapping does for the US, Canada and starting in the UK and what we at United Maps produce for Germany, Austria, Switzerland and the rest of Europe.

    As Ian rightfully states “Because data is not made available to Google (or anybody else) does not mean data is not available.” a possible extension is “most of data needed for hyperlocal maps is beyond the reach of search engines”. Which is certainly true for many elements, seamless multimodal routing and content hidden in the dark web – or stuff that simply still is analog.

  • It’s great to see this post on public transportation and the interesting and rewarding challenges it poses for software developers.

    The WMTA Customer Service Director’s comment that it is not in their best business interest to work with Google is frustrating. Transit agencies have so much to gain by opening themselves up to partnerships with other content providers.

    As a contrasting perspective, check out my interview with the CTO and GIS Manager for TriMet, which created the developer resources page you mentioned: Open source and open data make for transit innovation

  • @Ian – neither Jim nor I claimed that I was the definitive source for transit information – merely that we got into a conversation about the space and a lot of information fell out of it. Like any good article – it sparked just this type of discussion and gathering of people.

    Urban Mapping has done a lot of great work gathering and exposing much of the “dark” transit data. But then you sell this at a price that is again unattainable by small businesses and innovators. Part of my comments were about the value of making the data easily available – the value comes in the services integrated on top of the data and the monetary value of data by itself is quickly dropping.

    Open tools like GraphServer provide a great basis to build such services – as Ian points out. And hearing about similar projects (though sadly similar barriers as well) outside the US is encouraging. Hopefully the successful open transit agencies, projects and companies will forge the way, and succeed in the process.

  • Stefan – I can only speak for the UK, but OSM’s rural coverage is getting surprisingly good, fast. We have three advantages.

    Firstly, a small but dedicated set of countryside mappers has made great strides. A look around the New Forest area (Hampshire, UK) on OSM will show you what can be achieved.

    Secondly, we have out-of-copyright mapping (the Ordnance Survey’s New Popular Edition) which provides a good, traceable base layer. Urban areas have changed a lot in 50 years, but rural areas haven’t, which makes NPE hugely useful. There are actually similar public domain USGS topo maps for the States, though these are an underused resource for OSM – as yet.

    Thirdly, and I think most significantly, the OSM community is rapidly being augmented by walking, cycling and boating enthusiasts who are fed up with not seeing their routes shown on Google Maps et al. is the poster child, but another good example is that (a popular Snowdonia walking site) has just switched to OSM.

    On a side-issue, OSM’s geekiness is perhaps its advantage when it comes to public transport information. We can get away with screen-scraping. Google can’t. :)

  • Roy

    Jim – Good to see you bring-up the topic “State of Transit Routing” from an user’s perspective.
    Google (GTFS – Data Model), GraphServer (Routing – Application) and few others have done commendable work in the “Open Source” community, to address such user requirements. Unfortunately, the agencies doesn’t follow a standard nationwide data/application model. This is resulting in duplicate efforts from developers and agencies alike.
    Until such Data/Application standards are established it is not easy for the agency to share the data with geographically overlapping agencies or with developers who innovate the access of such information to an user like you and me.
    At we provide public transit directions in a region and not limit to an agency.

  • Quick, what’s the fastest + cheapest way to get from New York City to Erie, PA?

    Flying = $300 + 5 hours (through Detroit)
    Driving = $400 NYC rental + 6 hours
    Train = $200 + 7 hours
    Bus = forget about it

    Flying to Akron/Canton = 1.5 hours and $150, rental car from Akron/Canton = $100 with a 2 hour drive to Erie.

    If an app could tell me that, I’d love life a little more. Instead, I had to be a damn genius to figure that combination out and get to my cousin’s wedding in Erie, PA.

  • Jim Stogdill


    Great point. You’ve described a problem that I’ve had to solve hundreds of time for my work travel. It’s interesting because it is an optimization problem that spans transport modes and must account for preferences. Plus there are usually decision inputs like “is there a rental car counter at that train station?” or “is there a taxi stand at that metro station?” that influence the route chosen in sort of a binary way (objective function goes to zero if answer is no).

    In the example you give you were able to find a solution that was both quicker and cheaper, but usually that isn’t the case. The objective function will have to account for how you would weight the value of price and time.

    In my case, the objective function would also have to include a term that makes the value of the solution go to zero if the flight is over one hour and no aisle seat is available. Middle seat misery for usually trumps both cost and time for me. :)

    Thanks to everyone for great comments. Lots of great info.

  • Steve Palincsar

    I just tried google transit from where I live in Alexandria VA to a destination in downtown Washington DC. Although I live no more than 1.5 mi from a Metro stop, it routed me on two busses (one of them a Loudoun County long distance commuter bus!) that would take almost twice as long as walking or taking the bus to the Metro and then riding the train. That’s pretty amazing.

  • Steve Palincsar

    I just tried google transit from where I live in Alexandria VA to a destination in downtown Washington DC. Although I live no more than 1.5 mi from a Metro stop, it routed me on two busses (one of them a Loudoun County long distance commuter bus!) that would take almost twice as long as walking or taking the bus to the Metro and then riding the train. That’s pretty amazing.