county of san diego division of emergency medical services ems multivictim motor vehicle crashes in...

County of San Diego Division of Emergency Medical Services

EMS

Multivictim Motor Vehicle Crashes in San Diego County

Alan M. Smith, MPH; Edward M. Castillo, PhD, MPH; Barbara M. Stepanski, MPH; Leslie Upledger Ray,

MA, MPPA

County of San Diego Health and Human Services Agency, Division of Emergency Medical Services

County of San Diego Division of Emergency Medical Services

EMS

Multivictim – Annex D

• Tour bus rollover in snow• 30 miles from nearest hospital• 39 casualties• 7 Hospitals

– 5 trauma centers• 6 Ambulance Agencies

– 11 units• 3 Law Enforcement Agencies• California OES

County of San Diego Division of Emergency Medical Services

EMS

Background: Multivictim Crashes

• 7% of crashes 5 or more victims• Large demand on resources

– Emergency Medical– Hospital– Law Enforcement– Media coordination

• Incident Command Structure– Triage, crowd control, hazard management

• Communication – patient destinations

County of San Diego Division of Emergency Medical Services

EMS

San Diego County EMS Injury Surveillance

• Integrated Injury Surveillance System– Prehospital– Trauma System– Medical Examiner– SWITRS– GIS

County of San Diego Division of Emergency Medical Services

EMS

Methods: Data

• Statewide Integrated Traffic Records System (SWITRS)– Maintained by California Highway Patrol– Injury crashes for San Diego County– MVO crashes stratified by number of victims: 1,

2-4, 5-9, 10+– Fiscal year 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Methods: Analysis

• Number of victims in crash by:– Location– Time

• Hour, Day of Week, Month– Violation category– Type of collision

County of San Diego Division of Emergency Medical Services

EMS

Multivictim Crashes

• During FY 00/01, crashes with 5+ victims accounted for:– 7.3% of crashes– 21% of MVO victims– 15% of MVO injuries– 17% of MVO deaths

County of San Diego Division of Emergency Medical Services

EMS

Death Rate Per 1,000 Injuries by Number of Victims

8.8 8.59.5

14.2

02468

10121416

1 Victim 2-4 Victims 5-9 Victims 10 or moreVictims

Number of victims in crash

Dea

ths p

er 1

,000

vic

tims

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Number of Parties Involved

11%5%

61%68%

53%

13%21%

42%

26%

0%10%20%30%40%50%60%70%80%

1 Victim 2-4 Victims 5 or more Victims

1 Party 2 Parties 3 or more Parties

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Leading Violation Categories by Number of Victims in Crash

Rank of Violation Category

1 Victim 2-4 Victims 5-9 Victims 10 or More Victims

1Unsafe Speed

1714Unsafe Speed

2087Unsafe Speed

363Unsafe Speed

28

2Improper Turning

922Auto Right-of-Way

1119Auto Right-of-Way

127

Traffic Signals and Signs

6

3Auto Right-of-Way

773Improper Turning

715

Traffic Signals and Signs

85Improper Turning

4

4DUI Alcohol/Drugs

761

Traffic Signals and Signs

710DUI Alcohol/Drugs

84

Unsafe Lane Change

3

5

Traffic Signals and Signs

418DUI Alcohol/Drugs

552Improper Turning

79Auto Right-of-Way

2

6

Following Too Closely

228

Following Too Closely

278

Following Too Closely

37DUI Alcohol/Drugs

2

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Leading Collision Types by Number of Victims in Crash

Rank of Collision Type 1 Victim 2-4 Victims 5-9 Victims 10 or more Victims

1 Rear-end2041

Rear-end2562

Rear-end451

Rear-end32

2 Hit Object1392

Broadside2029

Broadside234

Broadside10

3 Broadside1302

Hit Object667

Sideswipe75

Sideswipe5

4 Sideswipe467

Sideswipe471

Head-on64

Hit Object3

5 Head-on224

Head-on449

Hit Object48

Head-on2

6 Overturned173

Overturned100

Overturned15

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Number of Victims by Road Type

Type of Road Number of Victims in Crash Major

Freeways Other State Highways

Other Streets and Roads

Total

1 Victims 29.1% 5.0% 65.8% 5704 2-4 Victims 27.8% 5.3% 66.9% 6351 5 or more 36.1% 6.7% 57.1% 949 Total 29.0% 5.3% 65.7% 13004

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Crashes by Month and Number of Victims

0100200300400500600700

January

Febru

ary

Marc

hApril

May

June

July

August

Septem

ber

October

Novem

ber

December

1 Victims 2-4 Victims 5 or more victims

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Multivictim Crashes by Month

020406080

100120

January

Febru

ary

Marc

hApril

May

June

July

August

Septem

ber

October

Novem

ber

December

5 or more victims

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Crashes by Day of Week

0200400600800

10001200

Mon

day

Tuesday

Wed

nesday

Thursday

Friday

Saturd

ay

Sunday

1 Victims 2-4 Victims 5 or more victims

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

County of San Diego Division of Emergency Medical Services

EMS

Multivictim Crashes by Day of Week

0

50

100

150

200

250

Mon

day

Tuesday

Wed

nesday

Thursday

Friday

Saturd

ay

Sunday

5 or more victims

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SWITRS database, FY 2000/01

Pacific Ocean

Mexico

Impe

rial C

ount

y

Riverside

POPULATION DENSITYSan Diego County by Subregional Area

Source: County of San Diego Health and Human Services Agency,Division of Emergency Medical Services, Medical Examiner Database

1996 - 2001

5 0 5 10 Miles

N

Population Density3.44 - 2004.952004.95 - 4006.464006.46 - 6007.986007.98 - 8009.498009.49 - 10011

Source: County of San Diego Health and Human Services Agency, Division of Emergency Medical Services, SANDAG Population Estimates, 1999.

County of San Diego Division of Emergency Medical Services

EMS

Map – Multi Victim Crashes

County of San Diego Division of Emergency Medical Services

EMS

Map – Multivictim by Number of Parties

County of San Diego Division of Emergency Medical Services

EMS

Results - Summary

• Multivictim MVO crashes made up – 7% of MVO crashes– 21% of victims– 17% of deaths

• Violation categories: – Unsafe speed overall– Traffic signals/signs higher in multivictim

• Collision types: – Rear end overall– Collision with object lower in multivictim

County of San Diego Division of Emergency Medical Services

EMS

Results – Summary

• Time– Peak in summer months, weekends

• Parties– 58% involve one or two victims

• Location– High population density (3+ parties)– Intercounty travel corridors (1-2 parties)

County of San Diego Division of Emergency Medical Services

EMS

Conclusions

• Multivictim crashes more often during non-work times (weekends, summer)

• Multi-vehicle crashes in areas with high traffic volume

• Single-vehicle crashes more likely on more open freeway corridors

• Emphasize importance of passenger safety – no more passengers than seat belts

County of San Diego Division of Emergency Medical Services

EMS

Conclusions (cont.)

• BIG events uncommon– 1-2 per year with >=20 victims

• Majority 1-2 parties– Emphasize seatbelt use

• Majority not on freeways• Multiparty crashes in urban settings

– Defensive driving

County of San Diego Division of Emergency Medical Services

EMS

Limitations

• Only 1 year of data• Limited info on drivers

– Residence– Destination

• Not linked to ambulance data

County of San Diego Division of Emergency Medical Services

EMS

Acknowledgements

• The data collection efforts of the police and sheriff departments throughout the County are gratefully acknowledged, as is the cooperation of State staff for providing the SWITRS data to San Diego County.

County of San Diego Division of Emergency Medical Services

EMS

Contact Information

Alan M. SmithCounty of San Diego

Health and Human Services AgencyEmergency Medical Services

6255 Mission Gorge RoadSan Diego, CA 92120 (619) 285-6429 phone

(619) 285-6531 faxAlan.Smith@sdcounty.ca.gov