Quantcast

DC Bikeshare’s uphill problem (and why I understand that physically now)

Capital Bikeshare at Nationals Park

After months of procrastinating, I bought a yearly membership to Capital Bikeshare. It’s been a good month now and I’ve been using it primarily for commuting. The ride is not busy at all, as the majority of my route rides along the Pennsylvania Avenue bike lanes, which are in the center of the road and have small breakdown lanes on either side.

But oh those Bikeshare bikes are heavy. At 40 pounds and three gears (at settings of “too loose to peddle” “hill, I guess” and “will move you more than 2 miles an hour on flat surfaces”), as the hero/insane person who used a bikeshare bike to race a triathalon (!) can attest, they are sturdy but painful to push against the smallest hill or stiffest wind.

“Whoever said that trail was flat, should try riding it on a Bikeshare,” hero/insane person Jefferson Smith told DCist.

I have one notable hill – 15th street along the Treasury building –  that fortunately has its own offset bike lane. Granted, I’m not in the best bicycling shape but that hill is long and deceptively steep. After a month I’ve already felt faster on straightaways and gotten better at picking up from a dead stop, but when I turn onto 15th, the next three blocks have never ever gotten easier. A phantom pain in my knee has generally stopped protesting when I go up the hill, but it’s still a real work out for my legs. Is it the 40-pound behemoth I’m dragging uphill along with my own weight? Or is it just a nasty hill?

Left and Leaving Co-efficient

That being said I have throughly enjoyed being a bike commuter, even on a heavy bike. I see plenty of people doing the same, although only about a  1/4 or a 1/3 are doing so on bikeshare.

Capital Bikeshare makes no secret that the system is designed for short around-downtown trips. The average trip is just over a mile. But there are stations everywhere around the city. For those who aren’t familiar with DC, downtown is set in a bowl. Which means, if you go far enough north or southeast (south is just Virginia, and that’s another story) you will be climbing some serious hills before it becomes flat again.

As I was signing up for Bikeshare, I noticed that they had a system data tab where they made public some of the data associated with the bikes. Among the data released are arrivals and departures by station. As a about-to-be new member I realized this could be helpful to me – noting which stations had high general turnover and which ones were likely to be empty/full.

But then I got a bit fancy.

The methodology of the  following analysis was done by essentially making it up, using a gut-level understanding and basic math skills. I took one statistics class in college, in which one day I walked out, returned a library book, had coffee and lunch, and returned to my seat, all as the professor stared at the board, never noticing my absence. So be forewarned, but I think this makes sense.

Here is the July 2012 Arrival and Departure data for the 11th and Kenyon stop:

  • Departures: 1828 Arrivals: 1364

(A quick moment to explain: bikeshare “rentals” are one-way. You take a bike out at station x and drop it off at station y. You may later take another bike from station y and drop it at station x, or even z, but that’s a separate trip. This means that in the month of July, 1828 bikes left the 11th/Kenyon stop and 1364 bikes were dropped off there. Bikeshare has vans that move bikes around to different stops as they fill and empty).

As I scrolled through the data, I noticed that some arrival/departure numbers were fairly equvalent, while others were several hundreds, even thousands apart.

So I made another column: Difference between departures and arrivals. Here’s the top 10.

Idaho Avenue and Newark Street NW 335
Georgia & New Hampshire Ave NW 338
Lamont & Mt Pleasant NW 378
39th & Calvert St NW / Stoddert 401
Columbia Rd & Belmont St NW 430
11th & Kenyon St NW 464
Park Rd & Holmead Pl NW 474
Adams Mill & Columbia Rd NW 504
14th & Harvard NW 562
16th & Harvard St NW 1008

Hey there 16th and Harvard.

Now this is the top 10 of difference in departures; these numbers represent how many more bikes are leaving a station than arriving in a month (July 2012).  The top 10 difference in arrivals would show how many more bikes arrived in a station than left it (none of these numbers include manual transfers by Bikeshare, I assume, so this is customer behavior.)

But the simple difference tells us nothing in relation to how busy the particular station is.

The stop by 7th and Maine SW will have nowhere near the volume of the stop by 21st/Penn, near many office buildings and a university . So a difference of 50 at Penn isn’t as significant as a difference of 50 at Maine.

Instead, what’s more interesting is the difference between departures and arrivals as a proportion of total trips. Please pause for math:

(Departures – Arrivals)/(Departures + Arrivals) = the Left and Leaving co-efficient.

The Left and Leaving co-efficient is named after a favorite song from the first year I lived in DC, by the underrated Weakerthans, but that’s mostly for my own amusement. What is represents is how significantly (NOT in a pure statistical sense ) each stop “left” more often by users. A stop with a high L&L co-efficient will have a systematic empty problem, possibly not just at rush hour. My guess is that bikeshare is already very very aware of this.

BUT WAIT, YOU’RE FORGETTING – yes I know: what happens to the L&L with stations where there are more arrivals than departures? I’m not going to bother reversing the top part of the equation when it can effectively show me a spectrum. It can have a negative value. Stops with high negative L&L’s  in theory will have the opposite problem – always being full.

An example of a negative L&L station: 13th and D NE – Departures – 1539 Arrivals – 1568 L&L: -0.01609323.

So what does the L&L co-efficient tell us, really? Let’s look at the top five highest and lowest L&Ls

Highest

39th & Calvert St NW / Stoddert Washington, DC 701 300 401 0.4005994006
36th & Calvert St NW / Glover Park Washington, DC 445 239 206 0.3011695906
Tenleytown / Wisconsin Ave & Albemarle St NW Washington, DC 711 383 328 0.2998171846
Idaho Avenue and Newark Street NW Washington, DC 730 395 335 0.2977777778
16th & Harvard St NW Washington, DC 2641 1633 1008 0.235844642

Lowest

C & O Canal & Wisconsin Ave NW Washington, DC 1866 2435 -569 -0.1322948152
7th & Water St SW / SW Waterfront Washington, DC 667 881 -214 -0.1382428941
Lynn & 19th St N Arlington, VA 1016 1354 -338 -0.1426160338
Georgetown Harbor / 30th St NW Washington, DC 1345 1846 -501 -0.157004074
Ft Myer Dr & Wilson Blvd / Rosslyn Metro Arlington, VA 695 959 -264 -0.1596130593

I’ve removed stations with less than 100 trips total for issues with sample size, but the first thing I notice is the high L&Ls are all at the top or midway up very steep hills. Bikeshare customers are leaving 16th and Harvard, near the Columbia Heights neighborhood, but they aren’t returning on bike. And with the exception of the 16th/Harvard and the Tenleytown stop, all are in exclusively residential areas. The other two are also very residential but are nearby commercial strips.

The lowest L&L’s? Yes, they’re generally downhill, but most places in Washington’s core are. Three are touristy or entertainment areas, and the other two are relatively close-in Arlington commute stops. With the Arlington stops, this suggests that commuters are more likely to take a bike back home rather than into work. At Georgetown Harbor, everyone is likely heading over for a meal or a drink at the end of the day, maybe getting a bit too tipsy to take a bike back. C&O is likely very busy and has many trips where tourists are taking the bikes out along the towpath and returning them to the same station.

None of the conclusions from the L&L co-efficient are particularly world shattering. I’m not shocked that people don’t like powering a 40 pound red monster up a massive hill on a busy city street.

But it’s nice at the end of the day when data matches up with the aches in your bones.

  1. cabi addict says:

    For your amusement, here are station elevations:

    “Id”, “Name”, “Elev(m)”, “Elev(ft)”
    1, “20th & Bell St”, 26, 85.3
    2, “12th & Hayes St”, 19, 62.3
    3, “20th & Crystal Dr”, 20, 65.6
    4, “15th & Crystal Dr”, 26, 85.3
    5, “18th & Hayes St”, 19, 62.3
    6, “15th & Hayes St”, 20, 65.6
    7, “S Joyce & Army Navy Dr”, 13, 42.7
    8, “18th & Bell St”, 42, 137.8
    9, “12th & Army Navy Dr”, 21, 68.9
    10, “27th & Crystal Dr”, 15, 49.2
    11, “S Glebe & Potomac Ave”, 7, 23
    12, “23rd & Crystal Dr”, 26, 85.3
    13, “26th & Crystal Dr”, 29, 95.1
    14, “19th St & Pennsylvania Ave NW”, 47, 154.2
    15, “14th & V St NW”, 37, 121.4
    16, “11th & Kenyon St NW”, 56, 183.7
    17, “16th & Harvard St NW”, 68, 223.1
    18, “Adams Mill & Columbia Rd NW”, 60, 196.9
    19, “14th & Harvard NW”, 62, 203.4
    20, “Calvert St & Woodley Pl NW”, 27, 88.6
    21, “Lamont & Mt Pleasant NW”, 69, 226.4
    22, “4th & M St SW”, 11, 36.1
    23, “15th & P St NW”, 33, 108.3
    24, “14th & R St NW”, 36, 118.1
    25, “14th & Rhode Island Ave NW”, 32, 105
    26, “20th & E St NW”, 26, 85.3
    27, “21st & I St NW”, 35, 114.8
    28, “Georgia & New Hampshire Ave NW”, 67, 219.8
    29, “14th & Spring Rd”, 61, 200.1
    30, “John McCormack Dr & Michigan Ave NE”, 47, 154.2
    31, “5th St & K St NW”, 15, 49.2
    32, “19th & East Capitol St SE”, 13, 42.7
    33, “Park Rd & Holmead Pl NW”, 62, 203.4
    34, “Good Hope & Naylor Rd SE”, 85, 278.9
    35, “Connecticut Ave & Newark St NW / Cleveland Park”, 68, 223.1
    36, “Randle Circle & Minnesota Ave NE”, 27, 88.6
    37, “Minnesota Ave Metro/DOES”, 18, 59.1
    38, “Nannie Helen Burroughs & Minnesota Ave NE”, 10, 32.8
    39, “Anacostia Metro”, 13, 42.7
    40, “Good Hope Rd & MLK Ave SE”, 21, 68.9
    41, “19th & E Street NW”, 17, 55.8
    42, “4th & Adams St NE”, 33, 108.3
    42, “4th St & Rhode Island Ave NE”, 31, 101.7
    43, “10th & U St NW”, 33, 108.3
    44, “Georgia Ave and Fairmont St NW”, 58, 190.3
    45, “1st & N ST SE”, 9, 29.5
    46, “20th St & Florida Ave NW”, 37, 121.4
    47, “7th & T St NW”, 28, 91.9
    48, “23rd & Eads”, 16, 52.5
    49, “M St & New Jersey Ave SE”, 6, 19.7
    51, “Massachusetts Ave & Dupont Circle NW”, 31, 101.7
    52, “1st & M Street NE”, 14, 45.9
    53, “21st & M St NW”, 23, 75.5
    54, “17th & K St NW [formerly 17th & L St NW]“, 37, 121.4
    55, “4th St & Massachusetts Ave NW”, 15, 49.2
    56, “3rd & D St SE”, 25, 82
    57, “Potomac & Pennsylvania Ave SE”, 22, 72.2
    58, “14th & D St SE”, 24, 78.7
    59, “17th & Corcoran”, 31, 101.7
    60, “Van Ness Metro / UDC”, 78, 255.9
    61, “Florida Ave & R St NW”, 26, 85.3
    62, “8th & Eye St SE / Barracks Row”, 24, 78.7
    63, “Ward Circle / American University”, 120, 393.7
    64, “Idaho Ave & Newark St NW [on 2nd District patio]“, 126, 413.4
    64, “Wisconsin Ave & Macomb St NW”, 121, 397
    65, “14th St Heights / 14th & Crittenden St NW”, 63, 206.7
    66, “Anacostia Library”, 22, 72.2
    67, “Pennsylvania & Minnesota Ave SE”, 10, 32.8
    68, “Eastern Market – 7th & North Carolina Ave SE”, 28, 91.9
    69, “McPherson Square – 14th & H St NW”, 42, 137.8
    70, “Benning Branch Library”, 32, 105
    71, “USDA / 12th & Independence Ave SW”, 21, 68.9
    72, “Georgetown Harbor / 30th St NW”, 11, 36.1
    73, “12th & Newton St NE”, 62, 203.4
    74, “US Dept of State / Virginia Ave & 21st St NW”, 20, 65.6
    75, “L’Enfant Plaza / 7th & C St SW”, 10, 32.8
    76, “10th St & Constitution Ave NW”, 9, 29.5
    77, “Kennedy Center”, 9, 29.5
    78, “Eastern Market Metro / Pennsylvania Ave & 7th St SE”, 26, 85.3
    79, “18th & M St NW”, 32, 105
    80, “Tenleytown / Wisconsin Ave & Albemarle St NW”, 120, 393.7
    81, “13th & H St NE”, 13, 42.7
    82, “5th & F St NW”, 26, 85.3
    83, “New York Ave & 15th St NW”, 40, 131.2
    84, “Convention Center / 7th & M St NW”, 27, 88.6
    85, “Harvard St & Adams Mill Rd NW”, 42, 137.8
    86, “19th & L St NW”, 36, 118.1
    87, “C & O Canal & Wisconsin Ave NW”, 24, 78.7
    88, “7th & Water St SW / SW Waterfront”, 8, 26.2
    89, “D St & Maryland Ave NE”, 25, 82
    90, “34th St & Wisconsin Ave NW”, 60, 196.9
    91, “13th St & New York Ave NW”, 46, 150.9
    92, “8th & H St NW”, 30, 98.4
    93, “10th & Monroe St NE”, 56, 183.7
    94, “Eckington Pl & Q St NE”, 30, 98.4
    95, “6th & H St NE”, 12, 39.4
    96, “3rd & H St NE”, 14, 45.9
    97, “Bladensburg Rd & Benning Rd NE”, 17, 55.8
    98, “4th & East Capitol St NE”, 31, 101.7
    99, “Lincoln Park / 13th & East Capitol St NE”, 28, 91.9
    100, “Branch & Pennsylvania Ave SE”, 45, 147.6
    101, “13th & D St NE”, 23, 75.5
    102, “16th & U St NW”, 39, 128
    102, “New Hampshire Ave & T St NW [formerly 16th & U St NW]“, 32, 105
    103, “Metro Center / 12th & G St NW”, 33, 108.3
    104, “14th & D St NW / Ronald Reagan Building”, 22, 72.2
    105, “7th & F St NW / National Portrait Gallery”, 29, 95.1
    106, “17th & K St NW / Farragut Square”, 31, 101.7
    107, “20th & O St NW / Dupont South”, 32, 105
    108, “4th & D St NW / Judiciary Square”, 20, 65.6
    109, “19th St & Constitution Ave NW”, 10, 32.8
    110, “37th & O St NW / Georgetown University”, 40, 131.2
    111, “11th & H St NE”, 16, 52.5
    112, “25th St & Pennsylvania Ave NW”, 29, 95.1
    113, “Columbus Circle / Union Station”, 13, 42.7
    114, “North Capitol St & F St NW”, 25, 82
    116, “36th & Calvert St NW / Glover Park”, 88, 288.7
    117, “14th & G St NW”, 36, 118.1
    124, “Ohio Dr & West Basin Dr SW / MLK & FDR Memorials”, 5, 19.7
    127, “Lynn & 19th St North”, 14, 45.9
    128, “Rosslyn Metro / Wilson Blvd & Ft Myer Dr”, 40, 131.2
    129, “Clarendon Blvd & Pierce St”, 66, 216.5
    130, “Court House Metro / Wilson & N Uhle”, St, 82, 269
    131, “N Rhodes & 16th St N”, 55, 180.4
    132, “Fairfax Village”, 95, 311.7
    134, “Wilson Blvd & N Edgewood St”, 76, 249.3
    135, “Columbia Rd & Belmont St NW”, 55, 180.4
    136, “17th & Rhode Island Ave NW”, 32, 105.0
    137, “Thomas Circle”, 32, 105.0
    138, “Wilson Blvd & N Franklin Rd”, 78, 255.9
    139, “Clarendon Blvd & N Fillmore St”, 79, 259.2
    140, “Clarendon Metro / Wilson Blvd & N Highland St”, 85, 278.9
    141, “18th St & Pennsylvania Ave NW”, 46, 150.9
    142, “Maryland & Independence Ave SW”, 4, 13.1
    143, “4th & E St SW”, 15, 49.2
    144, “3rd & G St SE”, 20, 65.6
    145, “7th & R St NW / Shaw Library”, 28, 91.9
    146, “9th & Upshur St NW”, 64, 210.0
    147, “1st & Rhode Island Ave NW”, 30, 98.4
    148, “Columbia Rd & Georgia Ave NW”, 62, 203.4
    149, “California St & Florida Ave NW”, 38, 124.7
    150, “Benning Rd & East Capitol St NE / Benning Rd Metro”, 29, 95.1
    151, “3000 Connecticut Ave NW / National Zoo”, 71, 232.9
    152, “Anacostia Ave & Benning Rd NE / River Terrace”, 9, 29.5
    153, “M St & Pennsylvania Ave NW”, 16, 52.5
    154, “15th St & Massachusetts Ave SE”, 25, 82.0
    155, “Congress Heights Metro”, 88, 180.4
    156, “N Quincy St & Glebe Rd”, 85, 278.9
    157, “Wilson Blvd & N Oakland St”, 90, 295.3
    158, “Alta Bicycle Share Programming 3″, 3, 9.8
    158, “N Veitch & 20th St N”, 62, 203.4
    160, “Fairfax Dr & Wilson Blvd”, 85, 278.9
    161, “Key Blvd & N Quinn St”, 53, 173.9
    162, “1st & K St SE”, 8, 26.2
    163, “39th & Calvert St NW / Stoddert”, 97, 318.2
    164, “1st & Washington Hospital Center NW”, 62, 203.4
    165, “Virginia Square Metro / N Monroe St & 9th St N”, 87, 285.4
    166, “Central Library / N Quincy St & 10th St N”, 81, 265.7
    167, “Washington Blvd & 10th St N”, 81, 265.7
    168, “Jefferson Dr & 14th St SW”, 8, 26.2
    169, “Smithsonian / Jefferson Dr & 12th St SW”, 17, 55.8
    170, “George Mason Dr & Wilson Blvd”, 84, 275.6
    172, “N Veitch & Key Blvd”, 70, 229.7
    173, “N Adams St & Lee Hwy”, 73, 239.5
    174, “15th & N Scott St”, 60, 196.9
    175, “Washington Blvd & 7th St N”, 83, 272.3
    176, “Ballston Metro / N Stuart & 9th St N”, 106, 347.8
    177, “N Randolph St & Fairfax Dr”, 93, 305.1
    178, “Jefferson Memorial”, 9, 29.5
    179, “Good Hope Rd & 14th St SE”, 11, 36.1
    180, “Glebe Rd & 11th St N”, 89, 292.0
    181, “N Quincy St & Wilson Blvd”, 86, 282.2
    182, “Fairfax Dr & Glebe Rd”, 84, 275.6
    183, “Gallaudet / 8th St & Florida Ave NE”, 25, 82.0
    185, “20th & L St NW”, 22, 72.2
    186, “12th & L St NW”, 35, 114.8
    187, “21st St & Pennsylvania Ave NW”, 28, 91.9
    188, “19th & K St NW”, 33, 108.3
    189, “Prince St & Union St”, 8, 26.2
    190, “Market Square / King St & Royal”, St, 14, 45.9
    191, “Saint Asaph St & Pendleton St”, 22, 72.2
    192, “King St & Patrick St”, 14, 45.9
    193, “15th & K St NW”, 40, 131.2
    194, “Commerce St & Fayette St”, 8, 26.2
    195, “Henry St & Pendleton St”, 12, 39.4
    196, “Braddock Rd Metro”, 19, 62.3
    197, “King St Metro”, 8, 26.2
    198, “24th & N St NW”, 28, 91.9
    199, “10th & E St NW”, 19, 62.3
    200, “22nd & I St NW / Foggy Bottom”, 36, 118.1
    201, “Utah St & 11th St N”, 89, 292.0
    202, “Barton St & 10th St N”, 68, 223.1
    203, “Arlington Blvd & Queen St N”, 46, 150.9
    204, “Lincoln Memorial”, 6, 19.7

    BTW over time you will find that the bikes aren’t as heavy as they were for your first few trips.

  1. There are no trackbacks for this post yet.

Leave a Reply