Location, Location, LocationReg Souleyrette

Gerald and Audrey Olson Professorof Civil Engineering

CTRE/Iowa State University

Safety Data and Analysis Tools Workshop

Sponsored by Transportation Safety

Planning Working Group (TSPWG)

TRB March 27-28, 2006

4 Topics

1. Iowa crash data GIS location and analysis systems

2. How we work with local agencies

3. Some issues in crash location

4. SAFETEA-LU and location

Crash Location

TraCS Incident Location Tool (ILT)– Custom GIS Application for

Location Capture– Tie Roadway Attributes to

Crash Locations– Useful for Geo-Locating

other types of Incidents– Integrated with TraCS– Stand-Alone for Location

Capture of Paper Reports– ALL Iowa crashes located

using ILT

Zooming In for Location Capture Measuring from an Intersection

Approving Location Results

Crash Analysis

• GIS-ALAS – SAVER– Accident Location and Analysis System/Safety, Analysis,

Visualization, and Exploration Resource – Analyst oriented, 10 years of data– Arc View/Avenue

• CMAT – Crash Mapping and Analysis Tool– Traffic Engineering/Design oriented – Annual Crash/Roads Snapshot, 5 years of data (00-04)– VB/Map Objects

• IMAT - Incident mapping and analysis tool– Law Enforcement oriented (includes citations)– Works with Local TraCS data (up to today, if desired)– VB/Map Objects

Collection (ILT) Analysis (CMAT/IMAT)

Leveraging User Familiarity and Existing

Source Code

Architectural Context

CMAT

Data Format Config

Safety Engineers/Planners

Validation Logic

Local Agency Database

Data Collection Software

(TraCS)

WAN

Enterprise Safety Information

System

GIS Data

IMAT

Data Format Config

Law Enforcement Agencies

Location Capture Software

Data Flow

Iowa DOT help to the locals

• TraCS• sharing crash data • crash analysis tools• TEAP studies• traffic safety fund grants (1/2% of

construction funds on top of HSIP)• free safety engineering training• support ITSDS …

• Quick-response service• Aides other agencies in obtaining, mapping,

and evaluating crash information. • Facilitates decision-making, effective

presentation of information, and education. • Activities

– Policy and Practice Assessment– High Crash Location Identification– Project and Site Review– Targeted Enforcement

Data Manager

Mobility Issues

6.87%

7.39%

10.27%

14.11%

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

FTYROW from Stop Sign

Under 45

45 - 64

65 - 74

75 and Older

FTYROW Making Left Turn

6.09% 6.34%

7.70%

10.52%

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

Under 45 45 - 64 65 - 74 75 andOlder

– Strategic Highway Safety Plan– Traffic Records Strategic Plan– MPO Plans

Iowa DOT District 1Rural Two-Lane Primary Road Fatalities and Major Injuries (1998-

2000)

Disclaimer: The Center for Transportation Research and Education presents these data as preliminary.

20 unlocated injury severities not represented.(0 Fatal, 20 Major Injuries)

Statewide Rural Four-Lane Primary Road* Fatal and Major Injury Crash Severities (1996-2000)

* Non-Interstate

Unlocated crash severities not represented.

BEFORE

AFTER

Change in bearing between road segments

Horizontal Curves

High Crash Curves

Before After

1993 -1995

1998 - 2000

Safety Audit

City of Des Moines1995 to 1999Ages 5 to 19

August 15 to June 15Monday to Friday

7:00 a.m. to 5:00 p.m.

School-AgePedestrian

Crashes

Middle Schools

Rural Alcohol-Related Fatal and Major Injury Crashes

Rural Alcohol-Related Crashes: Corridors Ranked by Frequency

Some not-so “simple” questions

Location methods• address• offset from known point

(intersection, bridge, crossing, milepost)

• Literal description• Smart map• Lat/long or other coordinates

(GPS)• Aerial photo

Multiple methods required

Spatial analysis methods

• Spot/Intersection Analysis

• Strip Analysis

• Cluster Analysis

• Sliding-Scale Analysis

• Corridor Analysis

Spatial statistics is an emerging area

Not a simple question

Where are the crashes?

• Crashes are not necessarily point events

• Some crashes may be located using different methods and degree of accuracy – Temporal (e.g. link

node to lat long)– Spatial (e.g., state

police v. local)– Techno (GPS v. smart

map)

?

Feature not

represented

Feature under

construction

Alignment OK

Alignment Off

Where are the roads? (Incorrect or incomplete cartography)

Where are the roads? (Improving cartography)

Alignment moves

Alignment stays put

What “was” the traffic volume on the road? (and other road attributes at the

time of the crash) – this is a biggy!

• Need traffic level for the year the crash happened

• Requires multiple files – in Iowa, working on going back past 1998 – difficult to do

• Was the road even there then? Is the road still there?

How to segment the road system?

• Requirements– Logical breaks (engineering

and public)– Relationship to inventory data– Long enough for

manageability and presentation

– Short enough to reflect important changes

– Clear and understandable to use

• Facility location and type– What is rural/urban?

Character is important …Designated “rural”

Can use attributes and/or proximity…Red: probable, Yellow: spatial @ 75’, Blue: possible + spatial

What is an intersection crash?

SAFETEA-LU Sec. 1401: Must Identify “Top 5%”

… not easy to do in many states

Collect data on all crashes?

YesSome, quality issue, or working on itNoNo Response

R Souleyrette, 1/2006

State system crashes mapable (x-y or milepoint)?

YesSome, quality issue, or working on itNoNo Response

R Souleyrette, 1/2006

Inventory data on all roads?

The “quadrennial needs” legacy

YesSome, quality issue, or working on itNoNo Response

State system as a percent of all public

roads

Can 1401 be met without GIS?

Kansas, for example …• Has crashes on system only • Has ≈ 70% of crashes

located to road by route milepost

• Does sliding spot (nongraphical) & “named intersection” (program)

• Assuming the 30% missing does not affect the outcome

• No brainer to do top 5%

Yes, but spatial systems can:

• Address integration issues – National level – conflation of

state cartography to federal base map

– State level – coordination of hundreds of local agencies on map development and update

• Enable proactive approaches

• Not only meet 1401 location challenges, also can…

Mason City

Waterloo

Cedar Rapids

Quad CitiesDes Moines

Council Bluffs

IowaCity

Ames

SiouxCity

DubuqueFort Dodge

Ottumwa

Marshalltown

Spencer

Clinton

1 yrof data

Crash Density – 1 Year AverageAnnual Fatal and Major Injury Crashes Per Mile

Sam

ple

- DRAFT

Sam

ple

- DRAFT

Mason City

Waterloo

Cedar Rapids

Quad CitiesDes Moines

Council Bluffs

IowaCity

Ames

SiouxCity

DubuqueFort Dodge

Ottumwa

Marshalltown

Spencer

Clinton

3 yrsof data

Crash Density – 3 Year AverageAnnual Fatal and Major Injury Crashes Per Mile

Sam

ple

- DRAFT

Sam

ple

- DRAFT

Mason City

Waterloo

Cedar Rapids

Quad CitiesDes Moines

Council Bluffs

IowaCity

Ames

SiouxCity

DubuqueFort Dodge

Ottumwa

Marshalltown

Spencer

Clinton

5 yrsof data

Crash Density – 5 Year AverageAnnual Fatal and Major Injury Crashes Per Mile

Sam

ple

- DRAFT

Sam

ple

- DRAFT

Mason City

Waterloo

Cedar Rapids

Quad CitiesDes Moines

Council Bluffs

IowaCity

Ames

SiouxCity

DubuqueFort Dodge

Ottumwa

Marshalltown

Spencer

Clinton

10 yrsof data

Crash Density – 10 Year AverageAnnual Fatal and Major Injury Crashes Per Mile

Sam

ple

- DRAFT

Sam

ple

- DRAFT

For more information …

• Reg Souleyrette

• Iowa State University

• 515-294-5453

• reg@iastate.edu

• www.ctre.iastate.edu/itsds