National Center for Statistics & Analysis - Research & Development - 400 Seventh St. SW - Washington, DC 20590

Research Note

U.S. Department

of Transportation

National Highway

Traffic Safety

Administration

July 1998

Injuries Associated With Hazards Involving

Motor Vehicle “Rollaways”

NHTSA’s National Center for Statistics and

Analysis (NCSA) recently examined data from

the Consumer Product Safety Commission’s

(CPSC) National Electronic Injury Surveillance

System (NEISS) on cases involving injuries

associated with motor vehicle “rollaways.” 

“Rollaways” are defined as situations in which a

motor vehicle, after the transmission has been

locked into a parked position, is believed to have

rolled either forward or backward by the

transmission purposefully or inadvertently

moving or slipping into another gear position. 

NEISS data on persons treated in hospital

emergency rooms for these injuries were

examined to determine the action or activity

involved in producing the injury, the injury

diagnosis and severity, the body region most

often injured, and the age of the injured person. 

CPSC’s NEISS collects data on a nationally

representative sample of consumer productrelated injuries treated in hospital emergency

rooms. NEISS is a 3-level system consisting of 

surveillance of emergency room injuries, followback telephone interviews with injured persons

or witnesses, and comprehensive investigations

with injured persons and/or witnesses. NEISS

obtains data from a sample of 79 of the 6,127

hospitals nationwide with at least six beds that

provide emergency care on a continuing 24-hour

basis. The data on injuries associated with

motor vehicle rollaways were obtained through

an agreement between NHTSA and CPSC to

collect data on injuries associated with specific

motor vehicle hazards that may not involve a

police-reported motor vehicle crash. Incidents

that do not involve a police-reported motor

vehicle crash would not be captured in

NHTSA’s major crash data collection systems,

e.g., the Fatality Analysis Reporting System

(FARS), the National Automotive Sampling

System (NASS) and Special Crash

Investigations (SCI). NHTSA has used NEISS

data previously to examine injuries related to

other specific types of hazards involving motor

vehicles (see NHTSA Research Notes: Injuries

Associated with Hazards Involving Motor

Vehicle Power Windows, May 1997 and Injuries

Associated with Hazards Involving Motor

Vehicle Batteries, July 1997).

During a one-year study period, November 1,

1994 through October 31, 1995, data from 12

cases of injuries associated with motor vehicle

rollaways were obtained from NEISS. Based

upon these 12 cases, an estimated 590 persons

nationwide were treated in hospital emergency

rooms for injuries resulting from an activity

involving the rolling away of a motor vehicle

during the one-year period. Tables 1 through 9

provide additional details on the persons injured

in incidents involving motor vehicle rollaways by

the action or situation which produced the

injury, the type of vehicle involved, the most

severely injured part of the body, the injury

diagnosis and severity, and the age and sex of

the injured person, respectively. (The

percentages may not add to 100% in every table

due to rounding.)
National Center for Statistics & Analysis - Research & Development - 400 Seventh St. SW - Washington, DC 20590

As shown in Table 1, the types of situations

reported by persons injured in motor vehicle

rollaways appear to be associated with

entering/exiting the vehicle or repairing the

vehicle in some way. Slightly less than half

(44%) of the persons injured in motor vehicle

rollaways were injured as a result of being struck

by the vehicle when attempting to reenter it in an

effort to stop the vehicle. Twenty-eight percent

(28%) of those injured sustained injuries as a

result of being thrown from the vehicle while

entering or exiting. Approximately 22% were

injured as a result of being in a collision between

the rollaway vehicle and a fixed object of some

kind (e.g., telephone pole, light pole, fence,

etc.). The remaining 6% sustained crush-type

injuries as a result of the vehicle rolling off of a

ramp.

Table 1

Estimated Number of Persons Injured in

MV Rollaways by Injury Producing Action

November 1994 - October 1995

Injury Producing Action Estimated

No. Of

Injured

Persons

% Total

Struck by Vehicle While

Attempting to Reenter

262 44%

Thrown From and Run

Over/Struck by Vehicle 

165 28%

In Collision Between

Rollaway Vehicle and

Fixed Object

129 22%

Crushed by Vehicle 

Rolling Off Ramps

34 6%

Total 590 100%

Almost two-thirds of the vehicles involved in

motor vehicle rollaways during the study period

were classified as passenger cars. Light trucks

or utility vehicles comprised the remaining 34%,

as shown in Table 2. Of the vehicles involved in

these rollaway-type incidents, almost 90%

involved vehicles with rear-wheel drive,

accounting for an estimated 519 injured persons. 

Four-wheel drive utility vehicles were involved

3% of the time and were responsible for an

estimated 20 injured persons. Of the 12

rollaway cases obtained during the study, none

specifically identified involvement of front-wheel

drive vehicles, therefore, injury estimates cannot

be made for incidents of this type. The

conclusion cannot be made, however, that no

persons are injured in incidents involving

rollaways of front-wheel drive vehicles. It may

be that very few front-wheel drive vehicles are

involved in rollaways, and as a result, no cases

were captured during the study period. It is also

possible that front-wheel drive vehicles may be

present in the category of vehicles with

unknown drive axle type. The distribution of

persons injured by type of vehicle power axle

can be seen in Table 3.

 

Table 2

Estimated Number of Persons Injured in MV

Rollaways by Vehicle Type

November 1994 - October 1995

Vehicle Type Estimated

No. Of

Injured

Persons

%Total

Passenger

Cars

 390 66%

Light

Truck/Utility

Vehicles

 200 34%

Total 590 100%
National Center for Statistics & Analysis - Research & Development - 400 Seventh St. SW - Washington, DC 20590

Table 3

Estimated Number of Persons Injured in MV

Rollaways by Vehicle Power Axle Type

November 1994 - October 1995

Vehicle

Power Axle

Type *

Estimated

No. Of

Injured

Persons

%Total

Rear-Wheel

Drive

 519 88%

4-Wheel

Drive

 20 3%

Unknown

Drive Axle

Type

51 9%

Total 590 100%

*No cases involving front-wheel drive vehicles were identified during the

study period, therefore, it was not possible to estimate persons injured in

rollaways of front-wheel drive vehicles.

Table 4

Estimated Number of Persons Injured in

MV Rollaways by Injury Diagnosis

November 1994 - October 1995

Diagnosis Estimated

No. Of

Injured

Persons 

% Total

Contusions 260 44%

Fracture 129 22%

Strain/Sprain 115 20%

Crushing 34 6%

Laceration 34 6%

Internal Organ

Injury

 17 3%

Total 590 100%

Forty-four percent (44%) of the 590 persons

estimated to have been injured by motor vehicle

rollaways were diagnosed as having contusions,

as shown in Table 4. About 22% (129) of the

persons injured were diagnosed with fractures,

while another 20% (115) were diagnosed with

strains or sprains. For the remaining 86

estimated injured persons, the injury diagnosis

ranged from lacerations to internal organ

injuries.

Table 5 presents the injury severity distribution

for the estimated number of injured persons in

motor vehicle rollaways. While about 21% of

those injured received a minor or serious

diagnosis, the majority of sustained moderate

injuries (79%). 

Table 5

Estimated Number of Persons Injured in MV

Rollaways by Injury Severity

November 1994 - October 1995

Injury

Severity 

Estimated

No. Of

Injured

Persons 

%Total

Minor 71 12%

Moderate 468 79%

Serious 51 9%

Total 590 100%

A large majority (84%) of those persons

estimated to have been injured in rollaway

incidents were treated and released, as shown in

Table 6. Approximately 16% (94) of the injured

were hospitalized, almost twice as many as the

estimated 9% of those diagnosed as having

serious injuries [see Table 5].

Table 6

Estimated Number of Persons Injured in MV

Rollaways by Medical Disposition

November 1994 - October 1995
National Center for Statistics & Analysis - Research & Development - 400 Seventh St. SW - Washington, DC 20590

Medical

Disposition 

Estimated

No. Of

Injured

Persons 

%Total

Treated and

Released

 496 84%

Hospitalized 94 16%

Total 590 100%

 

Less than half (41%) of those injured in

rollaway incidents sustained injuries to either the

upper trunk of the body (16%) or the upper

limbs (i.e., arms, wrist, fingers, 25%), as shown

in Table 7. A roughly equal number of persons

are estimated to have received injuries to the

lower limbs and lower trunk (31%) or head and

face (28%).

Table 7

Estimated Number of Persons Injured in MV

Rollaways by Most Injured Body Region

November 1994 - October 1995

Body Part Injured Estimated

No. Of

Injured

Persons

%Total

Upper Trunk 94 16%

Upper Limbs 149 25%

Lower Limbs 68 12%

Head/Face 163 28%

Lower Trunk 115 20%

Total 590 100%

Table 8 presents the distribution, by age, of the

estimated number of persons injured in incidents

involving motor vehicle rollaways. The

proportion of injured persons is almost evenly

distributed among the two age groups of 0 - 14

years (22%), 15 - 29 years (28%), while only

11% of those injured were in the 30 - 44 years

age group. It is interesting to note the

proportion of persons injured aged 60 and above

represents 39% of the total. The proportion of 

persons injured in this age group is much larger

for rollaway incidents than for other types of 

motor vehicle hazards, e.g., battery explosions

and radiator cap scalding. For example, none of

the persons injured in incidents involving battery

explosions were 60 years of age or older, and

approximately 4% of those estimated injured by

radiator cap scalding were in this age group. 

(See Injuries Associated with Specific Motor

Vehicle Hazards: Radiators, Batteries, Power

Windows, and Power Roofs, DOT-HS-808-598,

July 1997.)

Table 8

Estimated Number of Persons Injured

 in MV Rollaways by Age

November 1994 - October 1995

Age of Person Estimated No.

Of Injured

Persons 

% Total

0 - 14 Years 129 22%

15 - 29 Years 166 28%

30 - 44 Years 63 11%

Over 60 Years 232 39%

Total 590 100%

The proportion of persons injured in incidents

involving rollaways is evenly distributed when it

comes to gender, as shown in Table 9. Females

represent about 51% of the estimated number of

people injured in these incidents while males

represent 49%.

Table 9

Estimated Number of Persons Injured in MV

Rollaways by Gender

November 1994 - October 1995
National Center for Statistics & Analysis - Research & Development - 400 Seventh St. SW - Washington, DC 20590

Gender Estimated

No. Of

Injured

Persons

%Total

Female 298 51%

Male 292 49%

Total 590 100%

For additional copies of this research note,

please call (202) 366-4198 or toll free,

1-800-934-8517. For questions, please contact

Keith Poindexter at (202) 366-0018 or Kenneth

Hardie at (202) 366-6987. This research note

and other general information on traffic safety

may be accessed by Internet users at

http://www.nhtsa.dot.gov/people/ncsa.