Utilizing Transportation Data for Low Cost Safety Improvements

Utilizing Transportation Data for Low Cost Safety Improvements Samuel Sturtz Transportation Planner Iowa Department of Transportation samuel.sturtz@dot.iowa.gov Photo Credits: Ken West- Kenneth G. West Jr

Office of Systems Planning Forecasting & Modeling Statewide and MPO travel demand forecasting Estimating future automobile and truck volumes Corridor Analysis Cartography & Traffic Map production Traffic Monitoring (Weigh-in-motion, Video Log, Traffic Count Data) Grant Programs Federal And State Recreational Trails Iowa Clean Air Attainment Program ICAAP Iowa s Byways Transportation Alternatives

Planning Team Responsibilities o Long Range Planning o MPO/RPA Coordination o Modal Planning o Safety Planning o Freight/ Rail Planning o Transit Planning o Bike/Ped Planning o Statewide Analysis

Utilizing Transportation Data for Low Cost Safety Improvements Photo Credits: Ken West- Kenneth G. West Jr

What is GIS GIS=Geographic Information Systems o A computer system or program designed to capture, store, display and analyze data in a spatial format. o Uses in Safety o Identifying crash locations o Identifying roadway features o Analyzing relationships between features and crashes o Visualizing data o Data management

Statewide 4-3 Lane Conversion Analysis Background of Project Peer exchange opportunity Office abilities Current applications coming online Opportunities to implement Intuition Data driven

Feasibility of Study Factors for determining feasibility Roadway function and environment Overall traffic volume and level of service Turn volumes and patterns Frequent-stop and/or slow-moving vehicles Weaving, speed, and queues Crash types and patterns Pedestrian and bike activity Right-of-way availability, cost and acquisition impacts General characteristics: parallel roadways, offset minor street intersections, parking, corner radii, and at-grad railroad crossings

Limitations of Analysis Current Limitations of study Data Only as good as what is available Scope Entire state-reduces granularity of analysis Time

Analysis Structure Data Elements Network screening elements Roadway data elements Number of lanes Median type AADT Major and minor intersections Business and private entrances Additional data elements Intersection data base Signalized intersections Segment level crash data

Phasing of Analysis First Phase High level screening All segments including 4 lanes No median Two way 3,290 segments identified Varying lengths included AADT Further restricted=<18,000 Second Phase Geoprocessing and filtering Intersection Analysis Intersection database Buffer analysis to determine high concentrations of signalized intersections Access Density Calculated field within ArcGIS Per mile basis

Phasing of Analysis Third Phase Site Aggregation Dissolving feature within ArcGIS Only concerned with sites.5 miles or longer Manual Aggregation Disconnected but continuous sites Intersection Analysis Intersection database Buffer analysis to determine high concentrations of signalized intersections Crash Data Segment level crash data Select by identified locations Aggregate up to corridor potential candidates

Conversion Candidates

Iowa DOT Resources GIS Home http://www.iowadot.gov/gis/default.htm Rest Services Iowa DOT Rest Service Directory http://www.iowadot.gov/gis/about.htm# DNR Rest Service Directory http://programs.iowadnr.gov/geospatial/rest/ Open and Interactive Data Sources Interactive Map Portal http://iowadot.maps.arcgis.com/home/index.html Open Data Map Portal http://public.iowadot.opendata.arcgis.com/ Planning Guide http://www.iowadot.gov/systems_planning/planning_resource_guide.html