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