Category: Urban Planning

Developing a method to score Divvy station connectivity

January 4, 2014 / / 2 Comments

A Divvy station at Halsted/Roscoe in Boystown, covered in snow after the system was shutdown for the first time to protect workers and members. Photo by Adam Herstein.

In researching for a new Streetsblog Chicago article I’m writing about Divvy, Chicago’s bike-share system, I wanted to know which stations (really, neighborhoods) had the best connectivity. They are nodes in a network and the bike-share network’s quality is based on how well (a measure of time) and how many ways one can move from node to node.

I read Institute for Transportation Development Policy’s (ITDP) report “The Bike-Share Planning Guide” [PDF] says that one station every 300 meters (984 feet) “should be the basis to ensure mostly uniform coverage”. They also say there should be 10 to 16 stations per square kilometer of the coverage area, which has a more qualitative definition. It’s really up to the system designer, but the report says “the coverage area must be large enough to contain a significant set of users’ origins and destinations”. If you make it too small it won’t meaningfully connect places and “the system will have a lower chance of success because its convenience will be compromised”. (I was inspired to research this after reading coverage of the report in Next City by Nancy Scola.)

Since I don’t yet know the coverage area – I lack the city’s planning guide and geodata – I’ll use two datasets to see if Chicago meets the 300 meters/984 feet standard.

Dataset 1

The first dataset I created was a distance matrix in QGIS that measured the straight-line distance between each station and its eight nearest stations. This means I would cover a station in all directions, N, S, E, W, and NW, NE, SE, and SW. Download first dataset, distance matrix.

Each dataset offers multiple ways to gauge connectivity. The first dataset, using a straight-line distance method, gives me mean, standard deviation, maximum value, and minimum value. I sorted the dataset by mean. A station with the lowest mean has the greatest number of nearby stations; in other words, most of its nearby stations are closer to it than the next station in the list.

Sorting the first dataset by lowest mean gives these top five best-connected stations:

  1. Canal St & Monroe St, a block north of Union Station (191), mean of 903.96 feet among nearest 8 stations
  2. Clinton St & Madison St, outside Presidential Towers and across from Northwestern Train Station (77), 964.19 feet
  3. Canal St & Madison St, outside Northwestern Train Station (174), 972.40
  4. Canal St & Adams St, north side of Union Station’s Great Hall (192), 982.02
  5. State St & Randolph St, outside Walgreens and across from Block 37 (44), 1,04.19

The least-connected stations are:

  1. Prairie Ave & Garfield Blvd (204), where the nearest station is 4,521 feet away (straight-line distance), or 8.8x greater than the best-connected station, and the mean of the nearest 8 stations is 6,366.82 feet (straight-line distance)
  2. California Ave & 21st St (348), 6,255.32
  3. Kedzie Ave & Milwaukee Ave (260), 5,575.30
  4. Ellis Ave & 58th St (328), 5,198.72
  5. Shore Drive & 55th St (247), 5,168.26

Dataset 2

The second dataset I manipulated is based on Alex Soble’s DivvyBrags Chrome extension that uses a distance matrix created by Nick Bennett (here’s the file) that estimates the bicycle route distance between each station and every other station. This means 88,341 rows! Download second dataset, distance by bike – I loaded it into MySQL to use its maths function, but you could probably use python or R.

The two datasets had some overlap (in bold), but only when finding the stations with the lowest connectivity. In the second dataset, using the estimated bicycle route distance, ranking by the number of stations within 2.5 miles, or the distance one can bike in 30 minutes (the fee-free period) at 12 MPH average, the following are the top five best-connected stations:

  1. Ogden Ave & Chicago Ave, 133 stations within 2.5 miles
  2. Green St & Milwaukee Ave, 131
  3. Desplaines St & Kinzie St, 129
  4. (tied) Larrabee St & Kingsbury St and Carpenter St & Huron St, 128
  5. (tied) Clinton St & Lake St and Green St & Randolph St, 125

Notice that none of these stations overlap with the best-connected stations and none are downtown. And the least-connected stations (these stations have the fewest nearby stations) are:

  1. Shore Drive & 55th St, 11 stations within 2.5 miles
  2. (tied) Ellis Ave & 58th St and Lake Park Ave & 56th St, 12
  3. (tied) Kimbark Ave & 53rd St and Blackstone Ave & Hyde Park Blvd and Woodlawn Ave & 55th St, 13
  4. Prairie Ave & Garfield Blvd, 14
  5. Cottage Grove Ave & 51st St, 15

This, the second dataset, gives you a lot more options on devising a complex or weighted scoring system. For example, you could weight certain factors slightly higher than the number of stations accessible within 2.5 miles. Or you could multiply or divide some factors to obtain a different score.

I tried another method on the second dataset – ranking by average instead of nearby station quantity – and came up with a completely different “highest connectivity” list. Stations that appeared in the least-connected stations list showed up as having the lowest average distance from that station to every other station that was 2.5 miles or closer. Here’s that list:

  1. Kimbark Ave & 53rd St – 13 stations within 2.5 miles, 1,961.46 meters average distance to those 13 stations
    Blackstone Ave & Hyde Park Blvd – 13 stations, 2,009.31 meters average
    Woodlawn Ave & 55th St – 13 stations, 2,027.54 meters average
  2. Cottage Grove Ave & 51st St – 15 stations, 2,087.73 meters average
  3. State St & Kinzie St – 101 stations, 2,181.64 meters average
  4. Clark St & Randolph St – 111 stations, 2,195.10 meters average
  5. State St & Wacker Dr – 97 stations, 2,207.10 meters average

Back to 300 meters

The original question was to see if there’s a Divvy station every 300 meters (or 500 meters in outlying areas and areas of lower demand). Nope. Only 34 of 300 stations, 11.3%, have a nearby station no more than 300 meters away. 183 stations have a nearby station no further than 500 meters – 61.0%. (You can duplicate these findings by looking at the second dataset.)

Concluding thoughts

ITDP’s bike-share planning guide says that “residential population density is often used as a proxy to identify those places where there will be greater demand”. Job density and the cluster of amenities should also be used, but for the purposes of my analysis, residential density is an easy datum to grab.

It appears that stations in Woodlawn, Washington Park, and Hyde Park west of the Metra Electric line fare the worst in station connectivity. The 60637 ZIP code (representing those neighborhoods) contains half of the least-connected stations and has a residential density of 10,468.9 people per square mile while 60642, containing 3 of the 7 best-connected stations, has a residential density of 11,025.3 people per square mile. There’s a small difference in density but an enormous difference in station connectivity.

However, I haven’t looked at the number of stations per square mile (again, I don’t know the originally planned coverage area), nor the rise or drop in residential density in adjacent ZIP codes.

There are myriad other factors to consider, as well, including – according to ITDP’s report – current bike mode share, transit and bikeway networks, and major attractions. It recommends using these to create a “demand profile”.

Station density is important for user convenience, “to ensure users can bike and park anywhere” in the coverage area, and to increase market penetration (the number of people who will use the bike-share system). When Divvy and the Chicago Department of Transportation add 175 stations this year – some for infill and others to expand the coverage area – they should explore the areas around and between the stations that were ranked with the lowest connectivity to decrease the average distance to its nearby stations and to increase the number of stations within 2.5 miles (the 12 MPH average, 30-minute riding distance).

N.B. I was going to make a map, but I didn’t feel like spending more time combining the datasets (I needed to get the geographic data from one dataset to the other in order to create a symbolized map). 

You can have your free parking when I get my free cappuccino

November 20, 2013 / / 22 Comments

Kudos to this Chicago developer and their architect for blending the parking garage into the building. I still dislike that it’s visibly a parking garage. 

My friend Payton Chung has some very dry urban planner humor. Which I absolutely love. He wrote about parking minimums in Washington, D.C., and the current proposed zoning change that would reduce them (and included a reference to Chicago’s parking “podiums”). The best part is below:

Drivers’ inability to find free parking spaces outside their offices is no more deserving of a public policy response than my inability to find a free cappuccino waiting outside my office.

Free parking makes the world go round, doesn’t it.

Chicago’s train stations are dead zones

November 3, 2013 / / 10 Comments

Perhaps not all of them: Millennium Station, serving Metra Electric and South Shore Line trains, was rebuilt and given a facelift and new tenants (including a few restaurants) when the City of Chicago constructed Millennium Park atop it. And not Northwestern Station since it has two food courts, activity from the thousands of workers above, and the new(ish) French Market.

But look at Union Station and LaSalle Station – they tell passengers to stay away. It’s obnoxious (and noxious) to be in them. These two stations have quite the space available for pleasant activities and waiting areas. Union Station has the Great Hall and a bar but it’s also a Great Distance away from the platforms. LaSalle Station is probably the worst: a dozen machines squawk at waiting passengers – if there are any – to tell people who are blind where each track is. Every 3 seconds.

I made a video to demonstrate a little of how unlovable train stations are in the United States. Not every station has the squawk boxes right in the main, but empty, waiting area, but the desolation and difficult access is widespread.

There’s a whole lot of nothing at LaSalle Station. Photo by Jeff Zoline. 

Berlin day 2 itinerary during my 2012 trip

October 2, 2013 / / 4 Comments

Olympic stadium, as seen from the entry plaza. View all 88 photos in this set.

A Chicago friend designed my two-day Berlin itinerary, whether he knew it or not. He visited Berlin in March 2012 and sent me an email a week before I left for Europe describing in detail the various facets of the city, including transportation, I should visit. This itinerary is a mesh of his suggestions and what I actually did on Friday, August 31, 2012.

Take the S-Bahn to Olympiastadion. Make sure you note all the unused, but remarkably nice platforms. On exiting the station (toward the east) you get some great views of S-Bahn tracks and covered third rail heading into the city. Walk around the east side of the stadium (and think about how this is a place where Adolf Hitler opened the Olympics and the first television broadcast was done of, making a major plot point in the movie Contact).

Olympiastadion S-Bahn station platforms. The U2 line continues, but some trains may terminate at these platforms for events. 

I walked into the Olympic Stadium, walked 80% of its circumference, and noted all of the statues, some of the stelae, and read most of the historical information stanchions. I saw the swimming arena, which is still in use today (it seems to be a membership club, although not exclusive). The diving platform’s stair design has changed noticeably. The stands haven’t changed: they are covered in what looks like moss.

Disqus throwers statue by Karl Albiker. The accompanying sign said it was sculpted to show how powerful and masculine German male athletes (and Germans in general) were.

I then made a long walk to the north and west, past a Berlin football club and equestrian areas, towards the bell tower and Langemarckhalle (which is partly a memorial to the Langemarck battle in WWI, but now an exhibition about how that memorial was a myth and propaganda to encourage students to join the military). The ticket to get into Olympiapark also gets you on the elevator to the top of the bell tower (Glockenturm), giving you splendid views of the city in all directions. In the Maifield between the bell tower and the stadium, men were playing cricket. This humungous grassy area was used for youth rallies during the Nationalist Socialist (Nazi) era. From Wikipedia: “Maifeld (Mayfield) was created as a huge lawn (112,000 square metres, 28 acres) for gymnastic demonstrations, specifically annual May Day celebrations by Hitler’s government.”

Playing cricket in Maifield.

After another long walk, I exited the park and made my way to the U2 Olympia-Stadion station (note how the S- and U-bahn stations have slightly different names). This is where the U-Bahn museum is (it has weird hours, don’t expect it to be open), but before you enter, you can walk around the station house and get some INCREDIBLE views of an U-Bahn rail yard and shops facility.

The dreary-looking Olympia-Stadion station east of the Olympic Park.

Next, my friend told me, ride the U2 inbound to Eberswalder Straße (toward Pankow from Olympia-Stadion on the U2 line), and walk under the tracks a half-block south to the little stand with the tables outside. He wrote to me, “Have a spicy currywurst and a beer. You won’t regret it.” I ate it and drank a Berliner Pilsner and I didn’t regret it.

That spicy currywurst and beer under the U2 tracks. 

Next, walk back up to Danziger Strasse. Get on the eastbound/southeastbound M10 tram toward Warschauer Strasse U+S-Bahn stations. But get off at Frankfurter Tor, not the terminal.

Then, do this walk:

View recommended walk in a larger map

You’ll get a good view of some Soviet architecture on Frankfurter Allee, a cute walk through a gentrifying neighborhood with tons of lovely little shops, then see the massive, gritty S-Bahn station, the M10 Tram terminal, and the U-Bahn elevated terminal. (You’ll also walk past the hipster hotel my friend stayed in, Hotel Michelberger.) Then, you’ll end up seeing the Berlin Wall and East Side Gallery just before you cross the water from East Berlin into West Berlin – a profound act, to my friend, considering that it was not possible when we were born – and have a nice walk under the U1 el tracks up to a great elevated station.

Soviet architecture.

The beautiful Oberbaum Bridge taken from the north bank of the River Spree, near the Berlin Wall East Side Gallery. 

I didn’t walk under the U1 el tracks, but instead walked west along the East Side Gallery and then north on Andreasstraße. I stopped at a grocery store to get some grub and then boarded the U5 at Strausberger Platz, changing at Alexanderplatz U+S Bahnhof to the U8, getting off at Pankstraße and walking a block to the apartment I was staying in.

Artwork on the Berlin Wall. 

The name “Pankstrasse” written in a cool typeface.

N.B. I bought a day pass to use all transit minus Regio, IC, ICE intercity train service. I could use buses, trams, U-bahn, and S-bahn. I never waited more than 9 minutes for a train or tram. The average wait was probably 3-4 minutes. The day pass cost me $8.20. I was given access to a bicycle, which I rode on Thursday night with my hosts, but after walking around and taking transit all day, I declined to get it. I felt that I would be able to get around the city just as fast (or faster) by taking transit (yes, shocking, I know). I also wanted to ride lots of trains. Here’s the full gallery of photos from the day.

Department of Road Diets: the carbon tax

September 16, 2013 / / 6 Comments

Grand Avenue over the Kennedy Expressway. Its four lanes look like this – empty – most of the day. But then there are times of the day where people who bike, take the bus, and drive all need to “share the road”. That failed strategy has led to increased road rage, slow transit, and dead bicyclists. Time to put roads like this on a diet. 

My friend Brandon sent me an article about the one-page solution to (mitigating) climate change in the United States that NPR posted this summer.

But Henry Jacoby, an economist at MIT’s business school, says there’s really just one thing you need to do to solve the problem: Tax carbon emissions.

“If you let the economists write the legislation,” Jacoby says, “it could be quite simple.” He says he could fit the whole bill on one page.

Basically, Jacoby would tax fossil fuels in proportion to the amount of carbon they release. That would make coal, oil and natural gas more expensive. That’s it; that’s the whole plan.

This new carbon tax would support different infrastructure construction and expanded government agencies with which to manage it. It would support a Department of Road Diets. Road diets are projects that reduce the number of lanes for cars on a roadway, either by reducing the width of the roadway, or converting the general purpose lanes to new uses, like quickly moving buses or giving bicycles dedicated space.

See, in the carbon taxed future, people will want to drive less and use more efficient modes of transportation like transit and bicycles. And those uses will need their own space because the status quo in our cities (except the ones in the Netherlands) of having each mode compete for the same space isn’t working. It results in frustration, delay, and death.

Enter the Department of Road Diets. We have millions of miles of roadways that will need to go on diets so a department dedicated to such transformation would be useful. The agency would be in charge of finding too-wide roads and systematically putting them on diets, I mean, changing their cross section to less carbon-intensive uses.