New Bike Efficiency Mapping Article/Maps (not PGH)

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Jul 7 2014 at 12:48pm #

This was a really interesting read:


Why cars remain so appealing even in cities with decent public transit

By Emily Badger July 7 at 1:09 PM

I keep stumbling across a great transportation visualization project from the Social Computing Group at the MIT Media Lab, most recently in this Washington City Paper post. In a series of interactive maps, covering a dozen cities, the Media Lab has mapped the most efficient mode of transportation — by car, bike, foot or transit — between any two points in a city.

This is what such a map looks like in Washington, D.C., if, say, you’re beginning your trip from Capitol Hill, inside the green block:

Leaving from that part of town, more than half of Washington is reached faster by bike (yellow) than any other mode of transportation. The same is true of less than 1 percent of the city by transit (in blue). Here’s the lab’s method of figuring this out:

To make this map, we gridded up the city at the block-group level, and then computed the time using each mode of transport from the centroid of the source block group to the centroid of the destination block group using the Google Maps API. For driving, we added a buffer time for parking and walking, and then we compared the four resulting times and colored the block-group based on the minimum.

As a tool for planning your travel routes, or even picking a neighborhood to live in, this is a fascinating platform (albeit a limited one: yes, it doesn’t touch on comparative costs, the existence of bike lanes, or the impact of road congestion at different times of day). But beyond personal applications, this type of map has some policy implications, too.

Two things are particularly striking about the above picture: Cycling is a much more efficient mode of transportation than many people realize. And transit is startlingly not so. Seldom will it get you farther, faster, than a bike will. Here’s a picture of your transit prospects from the other side of the Anacostia:

Very little of the city — just one tiny patch of it — is accessed fastest by transit. This picture would no doubt look different if we removed bikes from the calculation entirely and simply compared cars and transit. But even then, the city would still look more broadly accessible to you from behind the wheel of a car. The same is true even if you live on a transit line:

(Photos did not transfer, obviously). Results similar for Philadelphia and Chicago, referenced later in article.


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Jul 7 2014 at 3:50pm #

For driving, we added a buffer time for parking and walking

But they didn’t for biking. It takes me several minutes to unlock my bike, stow the cable and ulock, attach the light I don’t want stolen, retrieve and don gloves, then repeat the whole process at the other end. I can skip some steps sometimes, of course.

They’re also assuming I parked my bike right at the starting point. Safety considerations might have led me to leave it elsewhere, such as at a nearby garage. The study accounts for walking to a transit stop, or walking to a garage to fetch a car, but pretends cyclists carry their bikes at all times.

Then of course you might need to change clothes or shower after a long ride; that’s rarely necessary with the other modes. But that’s harder to calculate.

It would have been interesting to see a more honest time comparison that at least tried to approximate setup and walking time for cycling. I expect that would somewhat unskew the results versus walking and transit.


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Jul 7 2014 at 3:56pm #

@Steven, but you can usually park your bike closer to your destination than you can with a car, and sometimes you don’t have to park it at all. And not everybody wears gloves etc., different locks take different amounts of time to use, etc. There’s only so much you can do with a study like this.
I would really like them to do Pittsburgh. The website says they did maps for places they lived. Does somebody know somebody there so we can get them to do a Pittsburgh study?


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Jul 7 2014 at 4:15pm #

Sure, but sometimes you can park a car right out front (say at your house or office), sometimes there’s a valet who handles parking, etc. It’s not a fixed time for cars either. My point is they decided to pretend that the time for cyclists was zero, and the time for motorists was nonzero.

Even if the startup time for cyclists varies more than the startup time for drivers, pretending it’s zero for one but using a fixed estimate for the other just biases the results.


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Jul 7 2014 at 4:40pm #

It would have been interesting to see a more honest time comparison that at least tried to approximate setup and walking time for cycling. I expect that would somewhat unskew the results versus walking and transit.

One point does not make statistics…
Team Decaf Tuesday’s Rides from Tazza D’oro start at 18:15 sharp. I am 1000 Technology Drive.
1. Getting there by car: 5 minutes to change ; 5 minutes to walk to garage, to get into car; around 45-50 minutes to get to Tazza, 5-10 minutes to find parking; 5 minutes to get bicycle, check everything, pump, to get on bike; 0-1 minutes to ride to the group. Total 65-76 minutes. Tried different routes.
2. 5 minutes change; 5 minutes to get bike, check, pump. to get on bike; 25-30 minutes ride (30 minutes if I do it without pushing it) to the group. Total 35-40 minutes. 6 miles using EFT, Saline, Boundary Neville, Elsworth, Highland.

I am riding with TDC 3rd year. I would say about 20 times per year. I tried to get to Tazza about 10 times and gave up completely.


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Jul 7 2014 at 5:49pm #

Taking your bike on transit, or keeping a bike at each end (a bike that you ride between home and transit station near home, and a separate bike that you ride between transit station near work and work) would also be a good combination. This “bike-train-bike” combination is popular in parts of Europe: .

It would be interesting to see a contour map of car travel times animated over the course of a day: watch the times grow at rush hour and shrink in off-peak hours.


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Jul 8 2014 at 5:45am #

One point does not make statistics…

Indeed. But your numbers provide a good illustration. You say 65-76 minutes for the car trip, including various “extras”. And, being fair, you compare it to a comparable bike trip that also includes extras, at 35-40 minutes.

But that web site doesn’t. They (in effect) compare your 55-65 minute car trip with (some) extras to the 25-30 minute cycling-only part of your bike trip, with no extras.

Just for fun, I used Google Transit to see how a bus might compare. It suggested walking 0.7 miles up to Fifth Avenue at Moultrie (using Brady Street, which isn’t very pedestrian-friendly) and catching a 71A or 71B, which at that time of day takes the bus 32-34 minutes to Tazza, it claims. Total transit time would usually make it a bit faster than a car (bus lanes through Oakland help I guess) but slower than a bike.


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Jul 8 2014 at 6:51am #

There are just so many variables in this sort of thing it all comes down to specifics.

Traffic is effected by time of day. Always snares cars, gets busses a little less so, bikes anywhere on the spectrum depending on riding style. Cyclists can also choose how hard or easy they ride.

End time is effected by parking situation for cars, and by whether the cyclists got flushed/sweaty and cares to look less flushed and sweaty when they get in.

The overall thrust is right. Biking is pretty fast. But we know this already by bike messengers / food delivery.

I have a simpler heuristic for my transportation choices. Life is short, if it’s a trip where driving would ANNOY me, I avoid it. That tends to include anything where I would wonder about parking. Public transit unfortunately just about always annoys me.

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