The Minnesota Department of Transportation collects traffic data on the freeway system throughout the Twin Cities Metro area. This data is made public via XML files. There are two types of data; detector and incident.
Real-Time Detector Data ( http://data.dot.state.mn.us/iris_xml/det_sample.xml.gz )
This file is in XML format and is updated every 30 seconds. It contains volume, occupancy, speed and flow data for each detector in the Twin Cities Metro area.
Real-Time Station Data ( http://data.dot.state.mn.us/iris_xml/stat_sample.xml.gz )
This file is in XML format and is updated every 30 seconds. It contains volume, occupancy, speed and flow data for each detector station in the Twin Cities Metro area.
Real-Time Incident Data ( http://data.dot.state.mn.us/iris_xml/incident.xml.gz )
The TMS configuration (corridors, stations and detectors) is defined in metro_config.xml.gz
The All Detector Report can be used for locating detectors and stations.
Mn/DOT has developed data tools for analysis of archived traffic data.
Other files often used by developers can be found on our TMS data site