Table of Contents
MN GIS/LIS Consortium
From the Chair
Composite Image Service
Chronic Wasting Update
Global Elevation Data
Accessibility Matrix & Maps
Access to Destinations Interactive Map Combines Open Services and Tools
By Mike Dolbow, News Editor
Thanks to the work of Minnesota government agencies, a private contractor, and a network of open source developers, groundbreaking new research from the University of Minnesota is now visible in an interactive web map. Minnesota GIS users are likely familiar with the individual components, but this may be the first time they have combined in this manner, in a project that embodies the word “mashup”.
The research project is “Access to Destinations”, an interdisciplinary research effort coordinated by the University’s Center for Transportation Studies (CTS), with support from a wide variety of government and non-government sponsors. The project’s latest tool is dubbed the “Metro Accessibility Matrix”: an interactive map that displays the spatial and temporal variability of accessibility, which measures how easy it is to reach various destinations using different transportation modes: bus, bike, walk, and car. Now, for the first time, planners and other people who make decisions about transportation and land use can visualize quantitative measures of transportation accessibility and how it changed over a decade from 1995 to 2005.
The number of jobs that can be reached within 20 minutes by bus at 8:00 am in 2005 from the census block (outlined in teal color) in the middle of the map.
“Previous accessibility results were snapshots, and were derived from models rather than being observed using measured travel times and actual land uses,” says the project’s principal researcher, Dr. David Levinson. The accessibility data is a natural fit for a map, given that each different neighborhood or block group has a unique level of accessibility. And as Levinson says, “The advantage of an interactive map is the ability of the user to see the places they are interested in and compare the data spatially, temporally, and by mode.” For example, a transit planner locating a bus route in Fridley could compare the transit, walk, bike, and auto accessibility of multiple areas in order to determine the best placement of the route.
CTS contracted with Houston Engineering to develop the interactive mapping application. When given the project’s parameters, Houston recommended an Open Source technology stack consisting of MapServer, a PostGreSQL / PostGIS database, and GeoMoose, the open source web mapping client created by Minnesota developers. The recommended stack worked well because CTS was already using MapServer in an existing application, and the open source technology fit inside the project’s budget constraints. Using the GeoMoose platform meant that the University could quickly get an application up and running with the functional requirements they desired.
As for providing a context for the accessibility data, that’s where Minnesota government agencies played a role by providing air photos and background basemaps as free, standards-compliant web services. Houston Engineering knew about the Metropolitan Council’s new metro-area Basemap and MnGeo’s Geospatial Image Server, and that both services could be consumed inside a GeoMoose client. Both services were a natural fit to help users orient themselves, find their areas of interest, and further understand the accessibility data.
The end result? “Planners seem very excited by the ability to easily generate accessibility reports for their study areas” says Levinson. And the GIS community can see first-hand the benefits of sharing open software, open services, and the knowledge of when to pull them all together.
To view the “Metro Accessibility Matrix” map, go to <http://a2d.umn.edu>. For more information about Access to Destinations, see the project website or contact Stephanie Malinoff, CTS Manager of Events & Outreach Services, at firstname.lastname@example.org or 612-624-8398.