identifying crash location from chicago traffic crash data

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


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


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


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.


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


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


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


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


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


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


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


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)


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


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


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


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


How many intersections?


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

[email protected]

(312) 742-1362

mailto:[email protected]

identifying crash location from chicago traffic crash data

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