nebraska crash outcome data evaluation system (codes)

Nebraska Crash Outcome Data Evaluation System (CODES)

Commercial Motor Vehicle Crashes in Nebraska, 1996-1999

Dan Christensen

Ming QuPrabhakar Dhungana

Nebraska Health and Human Services System

Definition

• CODES DBS: a database resulting from linking motor vehicle crash records (Crash), Emergency Medical Services records (EMS), Hospital Discharge records (HDD) and Death Certificates.

Definition (cont’d)• A Commercial Motor Vehicle (CMV): Any truck

having at least 2 axles and 6 tires, any vehicle displaying a hazardous materials placard, or any bus designed to transport 16 or more passengers including the driver

• Current: A CMV is designated as any vehicle weighing more than 10,000 pounds, and/or designed to transport 16 or more passengers including the driver.

Definition (Con’d)

• Large Truck: Any truck having a gross vehicle weight rating greater than 10,000 pounds.

• Passenger Vehicle: Any passenger car, light truck, or van weighing 10,000 pounds or less.

Introduction– More than 5,000 deaths occur each year in CMV

crashes, accounting for about 13% of all the traffic deaths in the U.S.

– Another 142, 000 people were injured in crashes involving CMVs in 1999

– In 1999, the estimated average cost for CMV crashes was more than $75,000

– Reducing CMV crashes is a national highway safety priority

Purpose

• To understand the pattern and nature of crashes involving CMVs in Nebraska

• To establish a baseline for CMV crashes surveillance in Nebraska

Method• Descriptive analysis using four years of Nebraska

CODES data (1996 to 1999)

• Compare injury severity, hospital charges, and various pre-crash factors between crashes involving CMVs and crashes not involving CMVs

• Examine the differences in demographics and behaviors of drivers for two-vehicle crashes (one CMV and one passenger vehicle)

Results Of the 170,669 motor vehicle crashes that occurred

from 1996 to 1999 in Nebraska, 10,939 (6.4%) involved CMVs.

These CMVs involved-crashes accounted for: 6.0% (26,867) of all persons involved in crashes 6.1% (4,140) of all crash injuries 18.4% (225) of all crash deaths 9.9% ($7,907,361) of all motor vehicle crash related hospital

charges

Year

Miles Traveled (millions)

CMVs in Injury

Crashes

Injury- involvement Rate

CMVs in Fatal

Crashes

Fatal- involvement Rate

1996 1,913 695 36.3 52 2.7

1997* 2,000 756 37.8 45 2.3

1998 2,088 669 32.0 45 2.2

1999** 2,178 752 34.5 60 2.8

**Average of 1998 and 2000 VMT

Table 1

Vehicle miles estimates are produced bi-annually. *Average of 1996 and 1998 VMT

Involvement in Injury and Fatal Crashes and Involvement Rates for CMVs in Nebraska

Rates are per 100 million vehicle miles traveled.

Year

Miles Traveled (millions)

PVs in injury

crashes

Injury - Involvem

ent Rate

PVs in Fatal

Crashes

Fatal - Involvement Rate

1996 14,281 18,433 129.1 325 2.3

1997* 14,706 18,624 126.6 357 2.4

1998 15,131 19,300 127.6 371 2.5

1999** 15,293 19,608 128.2 341 2.2

** Average of 1998 and 2000 VMT *Average of 1996 and 1998 VMTVehicle miles estimates are produced bi-annually.

Table 2Involvement in Injury and Fatal Crashes and Involvement Rates for Non-CMVs in Nebraska

Rates are per 100 million vehicle miles traveled.

Median Inpatient Hospital Charge by Crash Type in Nebraska, 1996-1999

0

2000

4000

6000

8000

10000

12000

14000

16000

1996 1997 1998 1999

year

Ho

spit

al c

har

ge

in $

CMV Involved

No CMV Involved

Occupant

Number of

Injuries% of

Injuries

Number of

Fatalities% of

Fatalities

CMVs 606 19.1 15 7.7

Non-CMVs 2,562 80.9 181 92.3

Total 3,168 100 196 100

Injuries and Fatalities in Multiple Vehicle Crashes Involving CMVs in Nebraska, 1996-1999

Table 3

Map 1

N=8,200

Fatal Crashes by Time of Day and Type of Crash, Nebraska, 1996-1999

0.0

5.0

10.0

15.0

20.0

25.0

30.0

MID-3AM

3AM-6AM

6AM-9AM

9AM-NOON

NOON-3PM

3PM-6PM

6PM-9PM

9PM-MID

Pe

rce

nta

ge

CMV Involved N=188 No CMV involved N=828

Fatal Crashes by Day of the Week and Type of Crash, Nebraska, 1996-1999

0.0

5.0

10.0

15.0

20.0

25.0

Mon Tue Wed Thu Fri Sat Sun

Pe

rce

nta

ge

CMV Involved N=189 No CMV involved N=859

Persons Involved 9,396 243,680 7,881

Percent Injured 20 12 4

Fatality Rate 15.4 1.4 0.4

Inpatients 175 1,126 11Median Charges

for Inpatients $12,572 $8,428 $8,497

* Restricted to crashes involving two vehicles

Fatality rate is per 1,000 persons involved.

Comparison of Outcomes for Passenger Vehicle Occupants and CMV Occupants Involved in Motor Vehicle Crashes*,

Nebraska 1996-1999

Outcome

Occupants of PVs involved in Crashes with CMV's

Occupants of PVs involved in Crashes with Other

PVs

Occupants of CMV's

involved in Crashes with

PVs

Figure 6Drivers Condition in Fatal Crashes by Type of Vehicle,

Nebraska, 1996-1999

99.2

65.2

0.8

27.3

0.0

7.6

0.0

20.0

40.0

60.0

80.0

100.0

120.0

CMV Driver Passenger VehicleDriver

Pe

rce

nta

ge

Unimpaired

Drinking

Other

Drivers responsible for crashes by crash severity, Nebraska 1996-1999

10%

47%

43%

Commercial MV Driver

Passenger VehicleDriver

No Contributing HumanFactor

40%

53%

7%

21%

78%

1%

PDO Injury

Fatal

Figure 8

Contributing Human factors in Injury Crashes by Type of Drivers, Nebraska 1996-1999

1112

1112

2

9 5

77

51

52

3

6047

0

20

40

60

80

100

120

PVs' Driver CMVs' Driver

Pe

rce

nta

ge

Other Failure To Yield Speeding/Too Fast

Ran Stop Sign or Signal Following Too Close Drove Left of Center

Improper Overtaking None

Contributing Human in Fatal Crashes by Type of Drivers, Nebraska 1996-1999

49 5

23

2

9

7

11

2

0

1

23

1

3

78

22

0

20

40

60

80

100

120

PVs' Drivers CMVs' Drivers

Perc

en

tag

e

Other Failure To Yield Speeding/Too Fast

Ran Stop Sign or Signal Following Too Close Drove Left of Center

Improper Overtaking None

Conclusions

• Crashes involving CMVs tended to be severe

• PV occupants were more likely to be injured or killed

when involved in crashes with CMVs

• PV Drivers were more likely responsible for crashes

involving CMVs

• CMV drivers were found to be impaired much less often

than PV drivers in both injury and fatal crashes

Recommendations

• Vehicle Modifications– Modify the structure of CMVs to make them

less likely to inflict injuries in collisions with other vehicles

– Make trucks more visible during night

– Improve truck braking system

• Enforcement

– Improve enforcement of existing laws against unsafe driving acts in the vicinity of CMVs.

– Enforcing following distance and vehicle speed

• Education and Training– Increase passenger driver education about the

differences between the performance of CMVs and passenger vehicles.

– Increase CMV driver education about passenger vehicle driver behaviors

– Develop CMV drivers training programs focused on defensive driving technique based on PV drivers’ unsafe driving habit.

– Train law enforcement officers about the hazards of unsafe driving acts in the vicinity of CMVs.

Acknowledgement

• NHTSA

• Nebraska Office of Highway Safety

• Nebraska CODES Advisory Committee