Can TomTom help solve the congestion problem?

By Felix Salmon
December 8, 2011

Traffic congestion is one of those problems to which there is no single silver-bullet solutions. If a city has too much congestion, the main thing it needs to do is build out much better public transportation infrastructure — something which takes many years and many billions of dollars. But failing that, or in the mean time, is there anything else?

Balaji Prabhakar reckons he can try to give prizes to people who drive at non-peak hours; it’s a cute idea, but I don’t think it scales. And then there’s congestion pricing, of course. But right now, there’s surprisingly little evidence that it actually works, and some evidence that it doesn’t, at least in the medium term: in London, congestion went up after it went down, and much of the small decline in congestion can be attributed to better public transportation rather than the congestion charge itself.

The people at GPS maker TomTom, however, have another idea about how to reduce congestion, at least at the margin. TomTom has a lot of Live devices, which are constantly transmitting their location; on top of that, every time the old-fashioned GPS devices get plugged in to a computer and upgraded, they also upload details of where they’ve been and when. And TomTom also has data from cellphone companies about how fast various phones are moving on certain streets at certain times of day.

Put it all together, and you get a very rich database of where to find congestion, both in terms of geography and in terms of time of the day and week.

This information can reduce congestion in one of two ways. Firstly, the information can directly change driver behavior. TomTom claims that it can reduce travel times by up to 15% — which obviously reduces overall congestion in and of itself a little bit, since that car is on the road for less time. And if we ever reach a point at which 10% of drivers are using that technology, then you see further benefits: enough cars get rerouted from busy to less-busy streets that the busy streets clear up a bit and move faster. Overall, TomTom reckons that congestion gets reduced for everybody by 5%, even if they’re not using any GPS device at all.

And then there’s bigger changes which can be made at the municipal level. TomTom has a whole business which sells congestion information to cities, which can then use that information to inform minor decisions like traffic-signal timings, and major ones like rebuilding roads. Historically, cities have needed clunky hardware like cameras and in-street loops to detect how much congestion there is; the TomTom data is cheaper than that, it’s much more precise, and it covers all roads rather than just the main arteries.

This is great news, right? Yesterday, for instance, we got detailed information on pedestrian congestion in NYC. The “pedestrian volume index” has now reached 113.2 from 100 in 2007, and we know about individual blocks with great specificity: on West 14th Street between Hudson and Eighth, for instance, there were 11,166 pedestrians per day between 4pm and 7pm in September, compared with 8,911 in May and 7,055 the previous September.

That’s very useful information — but it pales in usefulness when compared to equally detailed information on automotive congestion. Finally, we can settle once and for all whether the pedestrianization of Broadway has resulted in higher or lower traffic speeds. We can find out what happens to congestion when bike lanes are installed. And we can measure congestion overall in the city, with an eye to working out how much the deadweight cost of congestion is, and whether some kind of congestion charge might make sense. Most obviously, the real-time TomTom data is good enough that it can and should be used to adjust traffic signals in real time, as and when traffic jams appear.

So, is this happening? Turns out, that question is very difficult to answer. I spoke to a couple of TomTom executives three weeks ago, and they told me that they had done a little study, just for their own edification, on the Herald Square area, to see what happened to traffic speeds there when Broadway got pedestrianized. I asked if they would send it to me, and they said that they’d be happy to — they just wanted to check with the city of New York first.

And then, last week, I was told that a New York Department of Transportation Deputy Commissioner asked TomTom not to share its data with me.

TomTom is still looking for some data, somewhere in the world, that it can share with me — but I don’t have anything yet. And this data is very hard to find, for anybody outside TomTom: the company informs me that even TomTom’s own non-profit, The Traffic Foundation, which says that it will be “tapping into TomTom’s community of 50 million users”, has no access at all to this wonderful and enormous traffic database, which now has more than 4 trillion datapoints.

If this data were a little more public, researchers could plug away at it to see what the effects of infrastructure changes are on congestion, for instance, and to help create a set of best practices for what kind of interventions get the best congestion-reduction bang for the buck. But that doesn’t seem to be happening. And TomTom is very quiet indeed about which municipalities have bought its data, and what those municipalities are doing with it.

There’s an amazing opportunity, here, to use advanced statistical and quantitative techniques to painlessly improve city life: it’s exactly the kind of thing that the TED people got so excited about when they decided to award their TED Prize to The City 2.0. But I worry that TomTom is keeping this data far too close to its chest, and that cities like New York are similarly unhappy about the idea that it might become public in any way.

Of course, TomTom is a public company, with an obligation to its shareholders to maximize the amount of money that it can generate from its database. And it doesn’t want to annoy potential clients, especially not when its share price has been bumping along at very low levels for the past couple of years. Sooner or later this information is bound to start getting used widely — can’t Google just buy TomTom, already, and make it much more public? The entire company, after all, has a market capitalization of less than a billion dollars. The profit motive, here, shouldn’t get in the way of the massive public good that can come from this database.

More From Felix Salmon
Post Felix
The Piketty pessimist
The most expensive lottery ticket in the world
The problems of HFT, Joe Stiglitz edition
Private equity math, Nuveen edition
Five explanations for Greece’s bond yield
9 comments so far

Felix: I highly recommend Anthony Downing’s book on traffic congestion. He argues that congestion is not a problem but a solution – congestion is a solution to a resource allocation problem. Ergo, you will never find the silver bullet.

Posted by junkcharts | Report as abusive

Get ready for a slaughter of the sacred cows if this stuff ever gets out.

Just for starters–bike lanes may actually have externalities that render them, after those externalities are taken into account, counter-productive in terms of congestion and energy efficiency in precisely those high density urban environments where they are most popular–because the impracticality of widening roads makes traffic flow a zero sum game in terms of available paved area.

Posted by dwightcramer | Report as abusive

> “in London, congestion went up after it went down, and much of the small decline in congestion can be attributed to better public transportation rather than the congestion charge itself”

It’s hard to separate the two, when:
* Improvements in public transport were paid for with the congestion charge: the funds levied were ring-fenced for this purpose. John Prescott (then UK transport secretary) extracted this commitment from Gordon Brown (then UK finance secretary).
* The congestion charge in itself changes the comparative value-proposition of personal vs. public transport. If the effect is not statistically noticeable, all you have to do is increase the charge. In principle, it must eventually affect behaviour, and even if the charge is small, it will affect behaviour on some scale.

Posted by matthewslyman | Report as abusive

I’m curious as to whether this data is inclusive enough or even representative of the population at any given location. You say there’s a great deal of data, but you (or TomTom) simply don’t offer enough information on whether the TomTom user data plus cell phone company data is comprehensive enough to make any statements about relative or absolute congestion. My auto GPS is not a TomTom, for example, and I often turn off my phone GPS. I know many people with phones lacking a built-in GPS.

It’s not a bad concept in the abstract, but it doesn’t sound even partially thought out yet.

Posted by Curmudgeon | Report as abusive

Two things:

1. I think you’re on a much better track here to fight congestion than the congestion pricing route. I think there’s a lot of efficiency that can be gained through the use of gps. I think there is way more to be gained through driverless cars (which will use gps) which may not be that far away. Driving habits are just as important as routing when it comes to congestion.

2. I’d be willing to bet that TomTom not making this data available has much less to do with profit than it does with privacy concern. After all, it was NY DOT that turned you down, not TomTom. GPS data is a lightning rod issue right now. Just look at all the location data “scandals” that have occurred recently. Apple, Google, Facebook, CarrierIQ have all been burned. I think that private companies haven’t done a good job of selling the concept that this data is not personally identifiable. Most likely because it hasn’t always proven to be true.

Posted by spectre855 | Report as abusive

INRIX has this data today and would be happy to share it with you. Felix, you should reach out to a gentleman there named Jim Bak.

Posted by trafficgeek | Report as abusive

“TomTom is a public company, with an obligation to its shareholders to maximize the amount of money that it can generate from its database.”

What a pity that TomTom can’t act instead in its shareholder’s best interests.

If TomTom were obligated to maximize shareholder value — not the same as share-price value! — then the value delivered to shareholders through traffic flow improvements would likely count as enormous compared to the monetary value delivered by anything else that TomTom might do.

Consider the net benefits to the many de-facto shareholders who own only a sliver of the company through a mutual fund, but are fully invested in their own driving time.

Posted by E.D.R. | Report as abusive

Felix, you sound as excited as my grandmother the first time she used a webcam.. Alas, Google has had this technology for years…

“Live traffic data is available in major cities in the United States, France, Britain, Australia, and Canada, with new cities and countries frequently added. To see if live traffic is available in your area, hover your mouse over the square widget on the top righthand corner of the map. A menu with available layers for your map will appear. Click on Traffic to turn on the layer and view real-time traffic conditions.
Traffic conditions are shown based on data availability. If we don’t have enough data to calculate accurate traffic speeds for a road, then we won’t show traffic conditions for that road. This is the reason why you may see more live traffic results at certain times of the day.
Learn more about other Google Maps layers.”

Posted by beowu1f | Report as abusive

don’t forget for a minute that this is all a very complex band-aid. traffic volume will continue to grow and absorb all the savings you get from better routing around congestion. at some point, the road system with all its smartly guided vehicles will fill up again and the question of systemic shift to transit, different land use patterns, road pricing, etc etc will all have to be confronted again with much less wiggle room.

Posted by AnthonyTownsend | Report as abusive
Post Your Comment

We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see