To develop the Chicago Bike Map app, I had a problem I thought would be simple to solve: load train lines into a Leaflet-powered map. I had the train lines stored as a polyline shapefile but Leaflet can only read the GeoJSON format or a string of geographic coordinates representing lines.
I eventually found a solution (I can’t remember how) and I need to share it with you. The converter can do more than ESRI shapefiles to GeoJSON. It can reproject the data in the conversion. It can convert from several formats to several other formats.
The site is called MyGeodata Converter. You upload a ZIP file of geographic files – .shp and its companion files (.prj, .dbf, .shx), .kml, and .gpx. Let’s take the Chicago Transit Authority train lines shapefile straight from the City of Chicago’s open data portal. It downloads as a zipped collection of a shapefile and its buddies and we can take this file straight to the Converter and upload it. The Converter will unzip it and read the data; it will even identify the projection system (for Chicago-based geographic data, its common to use NAD83 Illinois StatePlane East FIPS 1201 Feet (SRID 102671, the same as SRID 3435).
The Converter will convert to one of the following formats, with same or new projection; accepts SQL statements to extract a subset of data:
- ESRI shapefile
- KML, KMZ
- Microstation DGN
- MapInfo File
About Steven Can Plan
I started this blog in 2007 as the writing assignment for an introductory urban planning class at UIC. It's about cities (mainly Chicago), GIS oftentimes, and transportation (mainly bicycling). Learn more about me, Steven Vance. I also write for Streetsblog Chicago.
Steven Can Plan is hosted on Dreamhost.
Chicago Bike Map App
The Chicago Bike Map app is a bike and street map stored entirely in your iOS device – no data connection required. The map is designed to look much like the City of Chicago's official printed and online bike map. The app works on iPhone, iPod touch, and iPad.
Highly Recommended Bike Products
The best value taillight. It has three red LEDs that alternate and provide extreme brightness. I have two of these.
I've used this pannier to carry groceries, books, my laptop, clothing, anything. I like it because it's stylish (but also "normal" looking at the same time), stands up on its own, is extremely durable, and has the most universal attachment system: two hooks.
Bells can be quite useful, especially to tell people in front that you're passing them. I like the ding-dong bell the best. It makes a solid DING and then DONG on the spring's return.
Joyride: Pedaling Toward A Healthier Planet by Mia Birk, With Joe (Metal Cowboy) Kurmaskie, Joe Kurmaskie, Jim Moore
I met Mia Birk in October 2011.
The Death and Life of Great American Cities (50th Anniversary Edition) (Modern Library) by Jane Jacobs
Making Maps: A Visual Guide to Map Design for GIS by John Krygier PhD, Denis Wood PhD
If you are going to make a map, whether it be hand drawn or digital, you should really give this book a read. Then read it every time you make a map. It will help make sure your maps are laid out sensibly, in a way that others can easily read, and that it doesn't include fluff or unnecessary data.