Post on 06-Feb-2018
Crash Locating in the State of Alabama:
Improving Safety on Rural Roads
University of Alabama
Randy K. Smith
University of Alabama, Center for Advanced Public Safety
Andrew J. Graettinger
David Brown
The University of Alabama
Timothy Barnett
Waymon Benifield
Jennifer Bleiholder
Samuel PooleAlabama Department of Transportation
Dana A. Steil
Harding University
Alabama Crash Statistics
2006 2007 2008 2009 2010
Fatalities 1,208 1,110 967 849 862
Crashes 139,800 135,300 124,000 123,731 128,348
*
* SHSP 2.0, released February 2012
*• ~68K Road miles
• ~28K State maintained
• ~40K approximately
evenly split between
cities and counties
Crash Locating in Alabama
• Route and Milepost
– On-System Crashes
– 2006 to 2009 ~48%
– Map-able
• But not in municipals
• Node-Link-Offset
– Off System Crashes
– 2006 to 2009 ~52%
• 34% municipals, 18% county
– Not map-able
Node-Link-Offset
• Officer in the field
looks up “location”
on PDF drawings of
Node-Link Maps
Examples – Link/Node/Offset
Link OffsetNodes
Examples - Intersection
Link OffsetNodes
Goal• Be able to map and analyze ALL crashes
• Start with getting nodes located for all State/Federal routes
including routes through municipals
– Every node has a Route/Milepost and a coordinate
– Route/Milepost HotSpot analysis through municipals
• Previously stopped at municipal limits
– Reverse that process and show Node/Corridor HotSpot Analysis
through municipals
• Spatial representation of nodes
• Use experienced learned from State routes to tackle off-
system crashes
Approach
• Take a base map and place a point everywhere a local road
crosses a state/federal road.
• Use low-cost/high volume labor (students) to select those
points and identify the corresponding node number from the
Node-Link Maps
• Dual Monitors with drawings on one monitor and point map
on another
• Repeat for off-system nodes
• Repeat for municipals if time/budget allows
Node-Link Drawings“Clickable” Interface
Second
Screen
Node-Link
Drawings
State of Alabama
• ~327K Nodes
– ~119K Off System
– ~208K On System
• 3 students (not the same for the duration)
– Part time 10-20 hrs/week
– ~9 months
– Trailed off
– Come and go
Nodes do not
exist on Link-
Node drawings
Small Intersection
treated same as large
intersection
Issues & lessons LearnedNode and Links
• Drawings are updated “as needed”
– Intersection points NOT on the
drawings
– Nodes on the drawings no longer an
intersection
– Simply hard to tell
– Nodes “suppose” to be unique, not
the case
– Node granularity an issue
• Rural “T” intersection, 1 node number
• Large Interstate cloverleaf, 1 node
number
Issues & lessons Learned
• Line work used not “Authoritative
Source”
• DOT working on source
• Overlapping labels
– State name (AL-6)
– Federal name (US 82)
– Local Name (McFarland Blvd)
• Input errors and individual variability
Commercial Vehicle
Crashes 2007-2008•MP highways
• CMV June 2009-
June 2011
Status• 98.9% of State routes completed
• 90.1% of rural/urban routes completed
• Previous issues need to be addressed to improve these
numbers
• QA shows >90% accuracy
– Working to identify issues and procedures
• Next Step
– Links
– Labels
– Improved “browse” capabilities
Benefits• State of Alabama uses the CARE Software System for Crash Data analysis and
warehousing
– Able to access 15+ years of historical crashes
– Able to map these historical crashes
– Experiences says 3-4 years best for AL
• Improved/Different Hotspot analysis
– Routes through municipals
– Temperature map grids
• DOT working toward LRS
• Improved Data Entry
– Reduce the burden on the officer
– Get the correct data to begin with
• Improved Selective Enforcement
2011 Alabama
Crash Data
~48% to ~85%
Search
Node
Number
Municipalities
Crashes
Crash
Report
Search
Rural
Access to
Crash Reports
• Privileged
• Complete form
• Diagram
• Narrative
Hotspots
Electronic Crash Reporting
• State of Alabama transitioning to all
electronic crash reporting – eCrash
– >95% agencies using eCrash
– ~85% of crashes in 2011
• Large agencies needing to get vendor
changes
– All DPS Officers have GPS units
– DPS Officers work ~24% of crashes
– Node-Link-Offset REQUIRED for off-System
Crashes for now
Current and Future Work
• Goal
– Given 1 suggest
the others
– GPS
– Point and Click
– 3 way
verification
• Authoritative
Source
• Links!!
Examples - GPS
Link OffsetNodes
Crash Locating in the State of Alabama:
Improving Safety on Rural Roads
University of Alabama
Randy K. Smith
rsmith@cs.ua.edu
University of Alabama, Center for Advanced Public Safety