identifying crash location from chicago traffic crash data
TRANSCRIPT
Traffic Crash Data:
Challenges & Opportunities
Abraham Emmanuel
Chicago Department of Transportation
Traffic Crashes By The Numbers
34,172 traffic fatalities in US in 2008
38% of the fatalities in U.S. involved a driver
with a blood alcohol level of above .01
In Illinois over 800 traffic crashes occurred
per day in 2009
The total estimated cost of crashes in Illinois
for 2009 was $5.3 billion
Most number of traffic crashes occur on a
Friday
Source of All Crash Statistics
The Traffic Crash Report (Form SR1050 in
Illinois) prepared by a law enforcement officer
Crash Data Life Cycle
By a Police
Officer at the
Scene or at the
Police Station
Recording ReportingCollection
By a Data
Entry Operator
at a Central
Location
By a
Statistician or
Data Analyst
Crash Data Saves Lives!
Millions of dollars are spent each year to make
roadways safer
With limited funds for improvement projects, how
do we prioritize the street segments and
intersections that needs safety improvement?
Representation of intersections crashes on Chicago’s west side. Larger bubbles means more crashes at that intersection
Crash Data is a Strategic Asset
Almost all roadway improvement decisions are
influenced by crash data Traffic Signals Modernization
Intersection Improvement
Street Widening
Enforcement Efforts
Roadway safety audit
Planning agencies, automobile manufacturers,
insurance companies, media, legislatures all
use crash data for a variety of planning and
operational purposes
But the Data these Decisions are
Based on have Many Limitations
Missing or
erroneous
information on
the crash
Recording ReportingCollection
Keying in errors.
Not all records
keyed in
Inconsistent
standards used in
developing stats
Data Availability Data Quality Overall
In City
Database
Not in State
Database
In IDOT
Database
Not in
Chicago
Database
Reporting
Error -
Incomplete(left
at least one of
the 10 key
fields blank)
Reporting Error -
Incorrect Reporting
(reported incorrect
information for one
of the 10 key fields)
Data Entry Error - City
(during data entry into the
database r one of the 10 key
fields were keyed in
incorrectly or was not keyed
in.)
Report Correction at
State (Because of the
quality check process at
IDOT the report was
modified when keyed in)
Data Entry Error - State
(during data entry at
IDOT data one of the 10
key fields was omitted
or incorrect information
was keyed in)
At least One
type of the
error
Summary 20 (19%) 0 (0%) 67 (61%) 25 (23%) 56 (52%) 35 (34%) 38 (35%) 103 (99%)
Study conducted by CDOT in 2008 showed that 99% of the Chicago traffic
crash data contained significant quality issues
Data Collection
By a Police Officer at the Scene or at a Police
District Office
On the Illinois Traffic Crash Report Form
Report is prepared after the fact. Based on
information provided by parties involved,
witnesses, and reporting officer’s own
assessment
Recording ReportingCollection
Data Collection Issues
A report has over 100 fields and many fields
have codes that are hard to remember
Many fields not filled or filled with the wrong
information
Apathy towards the value of crash data
Conflicting information provided by parties
Officers not well trained on the nuances of crash
data collection
Cannot determine where the crash occurred
and what caused the crash
Recording ReportingCollection
Statistics and facts
“The government are very keen on amassing
statistics. They collect them, add them, raise
them to the nth power, take the cube root and
prepare wonderful diagrams. But you must never
forget that every one of these figures comes in
the first instance from the village watchman, who
just puts down what he damn pleases.”
Sr. Josiah Stamp, President Royal Statistical Society 1930-1932, recalling an
anonymous English judge.
Recording ReportingCollection
Electronic Recording of the Crash Data
Paper forms brought into a central location for
data entry
A Data Entry Operator keys in the reports into
a database
IDOT and City of Chicago maintain two
separate data entry facilities. Duplicating the
efforts in Chicago and Springfield
Recording ReportingCollection
Data Recording Issues
Data Entry Operators make errors in keying in
the report
Some crash reports never get to the data entry
section
IDOT reviews crash reports and makes
corrections before data is keyed in
Some of the serious Chicago crashes will be
keyed in as a criminal incident and hence never
get reported as a traffic crash
Lag in data entry can be up to 6 months
Recording ReportingCollection
Crash Analysis and Reporting
Data keyed into the database is aggregated
and summarized using reporting tools
Crash address is geo-coded (longitude and
latitude identified) for mapping
In Chicago the nearest intersection is identified
based on the geo-coded longitude and latitude
Reports are presented as spread sheets,
graphs, and maps
Recording ReportingCollection
Statistical Reporting Issues
City and State apply different criteria for
counting mid-block and intersection crashes
State does not report crashes below $1500
damage value unless there is an injury. In 2009
there were about 37,000 crashes
No standard for counting crashes at
intersections that are very close to each other
How to interpret missing data
Recording ReportingCollection
1
2
3
5
6
4
7 & 8 – Not in the CPD top 30 list
10
9
Top Crash Locations in Chicago for 2006, City and State data shows different Locations
Chicago Sun Times, May 14, 2008
How many crashes at the intersection?
Jackson Blvd
Th
roo
p S
t
Throop &
Jackson1350 W
Jackson
Van Buren St
N
Possible Solutions: Draw circles with
fixed radius or refer to the Crash Report
Jackson Blvd
Th
roo
p S
t
100 ft radius1350 W
Jackson
Van Buren St
N
- Crash reports that said the crash is intersection related
Some of the key questions the
crash data should answer….
Where the crash occurred
What type of crashes are occurring and why
Are there locations that need immediate
attention
Are there traffic crashes at a location that can
be prevented
What is the result of a crash mitigation effort
What is the general trend in traffic crashes
Error free crash data is needed to conclusively answer these questions.
Quality Improvement Efforts
Train Police
Officers.
Focus on Key
Fields
Replace Paper
Reporting with
Electronic
Forms
Standardize
Reporting
practices
Recording ReportingCollection
Database
Training to Police Officers
Re-train officers and supervisors
Train the Trainers at the Police Academy
Revise the 16-Hour training curriculum at the
Academy
Develop online training modules
New directives to officers
Brochures and quick
reference guides
Recording ReportingCollection
Crash Reporting Training at the
Chicago Police Academy, August
2009
Multi Year Effort
Focus on a small number of key fields first
Engage experts in helping with the training
Draw attention to the significance of crash data
Identify police districts or even officers
consistently making errors
Evaluate before and after crash data to
determine the impact of training
Recording ReportingCollection
10 Key Fields
Crash Type (Angle, Rear End, Pedestrian, etc.)
Injury (K, A, B, C, O)
Unit Type (Driver, Pedestrian, etc.)
Intersection Related
At Intersection
Date of Crash
Crash Location
RD Number
Direction of Travel (Unit1 and Unit2)
Vehicle Maneuver Prior (Unit1 and Unit2)
Recording ReportingCollection
Online Training Supplement
Pocket Insert/Tri-fold, Fall 2010
Eliminate Paper Reporting
Data collection and recording combined into a
Web based crash reporting system
Eliminate data entry at a central point
Data entry and error check at the same time
Electronic crash diagramming
Real-time data entry avoids delay in recording
Will reduce the time for clearing the crash scene
Recording ReportingCollection
IDOT – Chicago Web MCR Project
A web based crash reporting system is being
developed as a joint effort between IDOT,
Chicago Police(CPD) and CDOT
Built as an add on to the R-Case comprehensive
case management system being developed at
CPD
Will be available on police squad cars and district
desks
Front-end and back-end validations will be built
into the application to reduce reporting errors
Recording ReportingCollection
Integration with External Systems
Integrate with external systems for faster and
accurate data collection
SOS / LEADS
Drivers License Reader
GPS Based Location Identification
City and State share data collected
One set of crash data vs. two separate data
sources that are currently maintained
Open for use by all Illinois police agencies
Recording ReportingCollection
Standardized Reporting
City and State apply same criteria for
counting crashes
Develop a system for reporting Statute (over
$1500 damage) and Non Statute crashes
Group and separate intersections as
appropriate to avoid under counting and over
counting of crashes at an intersection
City and State coordinate release of crash
data
Recording ReportingCollection
How many intersections?
Recording ReportingCollection
Progress to Date
Training:
Completed 2 years of classroom and online
training
Courses taken by over 10,000 Chicago police
officers
Web MCR /Data Integration Project:
About 60% of the diagramming tool completed
Web MCR will be integrated with the CPD’s R-
Case system in 2011
Questions?
Contact Info:
Abraham Emmanuel
Chicago Department of Transportation
(312) 742-1362