Tagbeach

How to ascertain the area of Chicago beach parking lots to find the largest one

This tutorial is a direct response to a question about which Chicago beach has the largest parking lot. Matt Nardella of Moss Design, in a response to a Twitter-based conversation about Alderman Cappleman’s suggestion that perhaps Montrose beach has too much parking, researched on Wikipedia to find the answer. This is where it said that Montrose beach has the largest parking lot of any of Chicago’s 27 beaches.

Now we’re going to try and prove which beach has the largest associated parking lot.

This tutorial will teach how you to (1) display Chicago beaches, (2) download data held in OpenStreetMap, (3) find the parking lots within the OpenStreetMap data, (4) find the parking lots near the beaches, and (5) calculate each parking lot’s area (in square feet). You can use this tutorial to accomplish any one of these three tasks, or the same tasks but on a different part of OpenStreetMap data (like the area of indoor shopping malls).

You’ll need the QGIS software before starting. You’ll also need at least 500 MB of free space. Start a project folder called “Biggest Parking Lots in Chicago” and make two more folders, within this folder, called “origdata” and “data”.

First, let’s get some data about beaches

Since we only want to know about the parking lots near Chicago beaches we need to get a dataset that locates them. This data is presumably within the same OpenStreetMap extract we’re waiting for, but it’s best to go to the most reliable source.

  1. Download the Parks – Facilities & Features shapefile from the City of Chicago open data portal. I’ve already verified that it has all the beaches (as points).
  2. Open the parks shapefile in a new document in QGIS (call it “map01a.qgs”). You might not see the data so right-click the parks layer and select “Zoom to layer extent”.
  3. Filter out all the points that aren’t beaches by using the query builder. Right-click the layer and select “Filter…” and input this filter expression: “FACILITY_N” = ‘BEACH’
  4. Your map will now show 26 points along an invisible lakefront and then the beach at Humboldt Park.
  5. For the rest of this tutorial we’ll reference the beaches layer as ParkFacilities.

Second, let’s get some data from OpenStreetMap

The easiest way to grab data from OpenStreetMap is by using QGIS, a free, open source desktop GIS application that has myriad plugins that match the capabilities of the heavyweight ESRI ArcGIS line of software. We can download OpenStreetMap data straight into QGIS.

  1. Click on the Vector menu and select OpenStreetMap>Download data.
  2. We want as much data as will cover the beaches information so in the Extent section of the dialog box choose “From layer” and select the beaches layer (called ParkFacilities).
  3. Browse to the “origdata” folder you created in the first task and choose the filename “chicago.osm”.
  4. Click OK and watch the progress meter tell you how much data you’ve downloaded from OpenStreetMap.
  5. Once it’s completed downloading, click “Close”. Now we want to add this data to our map.
  6. Drag the chicago.osm file from your file system into the QGIS Layers list. A dialog box will appear asking which layers you want to add.
  7. Select the layer that has the type “MultiPolygon”. This represents areas like buildings and parking lots.

Third, display the OpenStreetMap data and eliminate everything but the parking lots

We only want to compare parking lots in this dataset with beaches in the previous dataset so we need to eliminate everything from the OpenStreetMap data that’s not a parking lot. Since OSM data depends on tags we can easily select and show all the objects where “amenity” = “parking”.

  1. Filter out all the polygons that aren’t parking lots by using the query builder. Right-click the layer and select “Filter…” and input this filter expression: “amenity” = ‘parking’. Hopefully all the parking lots have been drawn so we can analyze a complete dataset!
  2. Your map will now show little squares, rectangles, and myriad odd shapes that represent parking lots around Chicagoland. (Most of these have been drawn by hand.) It should look like Image XXX.
  3. Since this data is stored in a projection with the codename of EPSG:3435 and the OpenStreetMap data is stored with codename of EPSG:4326 we need to convert the beaches to match the beaches (because we’re going to be using feet as a  measuring distance instead of degrees).
  4. Right-click the layer and select “Save As…” and choose the format “ESRI Shapefile”. Then click the top Browse button and select a location on your hard drive for the converted file.
  5. For “CRS” choose “Selected CRS”. Then click the bottom Browse button and search for the EPSG with the codename 3435. Select the checkbox named “Add saved file to map” so the new layer will be immediately added to our map.

Fourth, select all the parking lots near a beach

This task will select all the parking lots near the beaches. I chose 2,000 feet but you could easily choose a different distance. You might want to measure on Google Earth some minimum and maximum distances between beaches and their respective, associated parking lots.

(This task is easier using PostGIS which has a ST_DWithin function to find objects within a certain distance because we can avoid having to create the buffer in QGIS.)

  1. Create a 2,000 feet buffer. Select Vector>Geoprocessing tools>Buffer.
  2. In the Buffer(s) dialog box, select ParkFacilities (which has your beaches) as the “Input vector layer”. Choose a distance of 2000 (the units are pre-chosen by the projection and since we’re using a projection that’s in feet, the distance unit will be feet).
  3. Browse to your project folder’s “data” folder and save the “Output shapefile” as “beaches buffer 2000ft.shp”.
  4. Click “Add results to canvas” and then click OK.
  5. Double check that 2,000 feet was enough to select the parking lots. In my case, I see that the point representing Montrose beach was further than 2,000 feet away from a parking lot.
  6. Let’s do it again but with 3,000 feet this time, and saving the “Output shapefile” as “beaches buffer 3000ft.shp”.
  7. This time it worked and the nearest parking lots are now in the 3,000 feet radius buffer. You can see in Image XXX how the two concentric circles stretch out from the beach point towards the parking lots.

We’re not done. We’re next going to use our newly created 3,000 feet buffers to tell us which parking lots are in them. These will be presumed to be our beach parking lots.

  1. Use the “Select by location” tool to find the beaches that intersect our 3,000 feet buffers. Select Vector>Research Tools>Select by location.
  2. Follow me: we want to select features in parking 3435 [our parking lots] that intersect features in beaches buffer 3000ft [our beaches]. We’ll modify the current selection by creating a new selection so that we don’t accidentally include any features previously selected.
  3. You’ll now see a bunch of parking lots turn yellow meaning they are actively selected.
  4. Let’s save our selected parking lots as a new file so it will be easier to analyze just them. Right-click “parking 3435” and select “Save Selection As…” (it’s important to choose “Save Selection As” instead of “Save As” because the former will save just the parking lots we’ve selected).
  5. Save it as “selected parking 3435.shp” in your “data” folder. The CRS should be EPSG:3435 (NAD83 Illinois StatePlane East Feet). Check off “Add saved file to map” and click OK.
  6. Turn off all other layers except ParkFacilities to see what we’re left with and you’ll see what I show in Image XXX.

Fifth, let’s calculate

Calculating the area is probably the easiest part of this tutorial.

  1. Close all attribute tables you may have opened.
  2. Select Vector>Geometry Tools>Export/Add geometry columns and choose “selected parking 3435” as your input vector layer.
  3. Leave all other options as-is and press OK. When told about how QGIS can’t access something simultaneously, choose “Yes”.
  4. QGIS should have told you that “selected parking 3435” has been updated. Right-click the layer and choose “Open Attribute Table”.
  5. Scroll to the far right and you’ll see a new column called AREA. This represents the parking lot’s area in square feet.
  6. Click on the AREA column heading to sort it from smallest to largest. Scroll to the bottom of the list and you’ll find the parking lot with the largest area. Double check – is it near a beach?

Conclusion

With my analysis, and with the data available from OpenStreetMap when I created this tutorial, there are three abnormally large parking lots:

  1. A linear lot near the Lincoln Park Zoo and North Avenue beach (6.8 acres)
  2. A curving lot near Montrose Beach (4.75 acres)
  3. An irregularly shaped lot near Montrose Beach (4.5 acres)

There’s one major caveat in this analysis and that’s the missing parking lots on beaches south of Navy Pier. This means that no one has drawn them into OpenStreetMap so it’s time to start editing!

Update on the new Chicago harbor

Since I posted an article about new, non-auto infrastructure projects in Chicago, a lot of people looking for information on the 31st Street Harbor (now visibly underway) have come across my blog. For them, I give this update.

A new breakwater and new piers will be built. I really want to know what the floating eyeballs are for. I imagine they’re markers for construction.

I was counting people entering the Lakefront Trail from the 31st Street access point yesterday for an Active Transportation Alliance project. Afterwards, I moseyed over to get a glance at the construction.

This photo shows how the pier has been closed for construction. I hardly see anyone using the pier except just to walk down and back – it seems few people fish here.

Non-auto construction projects in Chicago

There are 17 construction projects listed here and none are about automobiles. Additionally, there is information about 2 studies for bus rapid transit-like projects.

Download all of these into Google Earth with this KML file.

A couple of these projects are being held up by the current Illinois roadway construction workers’ strike. UPDATE: Apparently a deal has been reached to end the strike.

Streetscapes

  • Blue Island/Cermak – I wrote about this project at length in October 2009. Construction should begin as soon as the strike is resolved. CONSTRUCTION UPDATE, 10-21-10: Bioswale, or creek, is mostly complete at Benito Juarez Community Academy (BJCA). Plaza with permeable pavers, and sheltered bike parking also complete. Photos here.
  • Congress Parkway – Full details and renderings from CDOT (PDF). Project should begin in 2010 and will narrow lanes, reduce number of lanes, straighten lanes (no more mid-intersection lane shifts), widen sidewalks, and improve crosswalks. Will add a lot of landscaping and unique and decorative lighting.
  • PROPOSED: Lawrence Avenue between Ashland and Western. Reduce the number of travel lanes from four to three, adding bike lanes and a center turn lane. Project limits include the rebuilt Ravenswood Metra station at 1800 W Lawrence. More details on Center Square Journal. Construction wouldn’t begin until 2011.

Transit

  • Morgan/Lake Green and Pink Line CTA station (new) – Details and renderings from CDOT (PDF) – Overview from Chicago Transit Authority – Tons of bike parking included at the beginning, how it should be. Construction should start this year. To better serve the West Loop area, where more people are moving to, but also has lots of existing businesses.
  • State/Grand Red Line CTA station renovation – Construction should finish this year.
  • 35th/Federal Rock Island Metra station (new) – Construction started in 2010.
  • LaSalle/Congress Intermodal Center – To improve connection between buses and the LaSalle Metra station. Mentioned in the Congress Parkway streetscape presentation (PDF).
  • Wilson Red Line CTA station renovation – Down the street from a new Target store that opens this weekend and hundreds of brand new housing units in the Wilson Yard development. Will use TIF funds from the Wilson Yard district. Overview on CTA Tattler.
  • Ravenswood Metra Station – A popular station on the Union Pacific-North line (to Kenosha). Will add longer and sheltered platform and become accessible. Details with Chicago Square Journal.
  • FLOATING: New Green Line CTA station at 18th or Cermak. Roosevelt station serves three lines. South Loop neighborhood fast growing. The new station would improve transit access to McCormick Place (at least if built at Cermak). Follow the Chicago Journal for more news on this topic.

morgan cta station rendering

Rendering from the Chicago Department of Transportation (CDOT) showing context-sensitive design. See the full presentation (PDF) for architectural influences.

Bridges

  • Halsted Street over North Branch Canal of the Chicago River. Replaces 99-year old moveable span with fixed span. No information on how it will accommodate the Halsted Street bike lane. Construction to begin in 2010 (PDF). CDOT project number 74062.
  • Navy Pier Flyover – Elevated section of the Lakefront Trail to bypass current bottleneck where the Lakefront Trail currently enters the Lake Shore Drive bridge over the Chicago River and DuSable park. Details from CDOT presentation on July 15, 2010.
  • PROPOSED: 35th Street pedestrian bridge over Metra/Illinois Central tracks and Lake Shore Drive to lakefront and Lakefront Trail. Bridge will be self-anchored suspension, like the new Bay Bridge from Oakland to San Francisco. Overview on Burnham Centennial (drawing says 2007).

Rendering of the Navy Pier Flyover as it travels over the Lakepoint Tower condominiums as seen at the Cities and Bicycles forum with David Byrne in June at the Chicago Cultural Center.

Other

  • Various CREATE projects. All CREATE projects involve railroads in some way and most projects will construct grade separations. I’ve written about CREATE.
  • The Chicago Park District opened a new beach at Oakwood/41st Street this year. The grand opening for the beach house happened this past Saturday.
  • The Chicago Park District is currently building a harbor and marina immediately south of the 31st Street beach. The Public Building Commission of Chicago has the details and renderings. AECOM, the architect of record, produced these concept drawings (PDF). It appears how bike riders currently navigate the intersection at the entrance to the beach will change to be a little more normal and not force bike riders on the sidewalk. It’s unclear how many new parking spaces are being created along the lakefront – the fewer the better. The concept plan shows a new parking lot on the west side of the railroad tracks, a design I wholly support.
  • FLOATING: Luann Hamilton mentioned at the Cities and Bicycles forum with David Byrne in June that CDOT was thinking about a buffered bike lane on Wells Street.

31st street harbor concept rendering

Rendering of the 31st Street harbor concept plan. As seen in the contractor’s presentation to the Public Building Commission of Chicago.

Related

Although not construction projects, two additional proposals merit your attention. The Chicago Department of Transportation and the Chicago Transit Authority each received grants this month to study and develop two corridors with bus rapid transit-like features. CDOT’s plan is to develop a priority bus lanes for up to seven routes between the Metra stations and Navy Pier and North Michigan Avenue (the Miracle Mile). Thank you to Kevin Z for the update.

CTA’s grant money is to fund the development of a speedy bus service from the southeast side to the West Loop via the north-south Jeffrey Avenue.

What summer wants you to buy

According to an ad I heard on the radio, Summer is the perfect time to buy a new Toyota Corolla or RAV4.

I wholeheartedly disagree. Summer is the perfect time to have an oil spill in the Gulf of Mexico, closing beaches and damaging Gulf economies.

Take a ride to an un-oiled beach with your friends and your bikes.

I mean…wait. It’s the perfect time to get a new or used bicycle for yourself, a neighbor or a friend!

Blue City Cycles, along with the 100+ other local bike shops in Chicagoland, are ready and willing to help you select or build a new or used bike.

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