The Large Truck Crash Causation Study (LTCCS) is based on a three-year data collection project conducted by
the Federal Motor Carrier Safety Administration (FMCSA) and the National
Highway Traffic Safety Administration (NHTSA) of the United States Department of Transportation (DOT).
LTCCS is the first-ever national study to attempt to determine the critical events and associated factors that
contribute to serious large truck crashes so agencies within DOT and others can implement effective countermeasures to
reduce the occurrence and severity of these crashes.
For further information about the study please see the Study Methodology and database User’s Manual.
An introduction to the study results are provided in the following summary tables.
The tables have been organized into two categories
representing "Un-weighted" and "Weighted" results, with the specifics detailed below.
Notes:
- Throughout the study materials and the summary tables, "truck" refers to a vehicle designed, used, or maintained primarily for carrying property, with a
gross vehicle weight rating or gross combination weight rating of more than 10,000 lbs.
- In the summary tables:
- Percentages are rounded to the nearest whole number with values less than .5 percent rounded to zero.
- Totals and sub-totals are summed using unrounded estimates; therefore they may not appear to equal the sum of the relevant variables.
Un-weighted Data
†(Source: Large Truck Crash Causation Study (October 2005) - Un-weighted Data)
The tables in the "Un-weighted Data" section provide the actual study results for the table’s subject area.
Table 1: Crashes by Vehicle Count
This table shows the number of crashes in the study sample cases by the total number of vehicles involved in each crash.
†
Vehicle Count |
Crash Count |
Percentage |
One |
241 |
25% |
Two |
488 |
51% |
Three or More |
234 |
24% |
Total |
963 |
100% |
Table 2: Crashes by Severity Level
This table shows the number of crashes in the study sample cases by the highest injury severity level of any individual involved in the crash.
†
Crash Severity |
Crash Count |
Percentage |
K − Fatal |
221 |
23% |
A − Incapacitating injury |
277 |
29% |
B − Non-incapacitating injury |
465 |
48% |
Total |
963 |
100% |
Table 3: Crashes by Roadway Type
This table shows the number of crashes in the study sample cases by type of roadway on which the crash occurred. For crashes involving multiple roadway types, e.g. intersections, the roadway type is determined from the perspective of the vehicle associated with the critical reason for the crash. The critical reason is the reason for the critical event.
†
Roadway Type |
Crash Count |
Percentage |
Rural |
350 |
36% |
Principal arterial − Interstate |
109 |
11% |
Principal arterial − other |
78 |
8% |
Minor arterial |
62 |
6% |
Major collector |
26 |
3% |
Minor collector |
31 |
3% |
Local |
37 |
4% |
Unknown |
7 |
1% |
Urban |
609 |
63% |
Principal arterial − Interstate |
344 |
36% |
Principal arterial − Freeways and Expressways |
63 |
7% |
Principal arterial − other |
78 |
8% |
Minor arterial |
44 |
5% |
Collector |
22 |
2% |
Local |
58 |
6% |
Unknown |
4 |
0% |
Total |
963 |
100% |
Table 4: Crashes by Crash Type
This table shows the number of crashes in the study sample cases by crash type, e.g. rear-end, head-on, etc. Crash type is determined from the perspective of the truck. The crash type of crashes involving two or more trucks is determined from the perspective of the truck assigned the critical reason.
†
Crash Type |
Crash Count |
Percentage |
Rear-end |
231 |
24% |
Roadside Departure |
158 |
16% |
Sideswipe, Same Direction |
111 |
12% |
Turn Across or Into Path |
94 |
10% |
Intersecting Vehicles, Straight |
64 |
7% |
Rollover |
61 |
6% |
Hit Object in Road |
43 |
5% |
Sideswipe, Opposite Direction |
42 |
4% |
Head-on |
34 |
4% |
No Impact − includes incidents such as fire or immersion. |
12 |
1% |
Backing |
7 |
1% |
Other − principally trucks not involved in first harmful event, or cargo spills |
106 |
11% |
Total |
963 |
100% |
Table 5: All Trucks by Vehicle Configuration
This table shows the number of trucks in the study sample cases grouped by truck configuration.
†
Vehicle Configuration |
Number |
Percentage |
Single Unit Trucks |
Two Axles |
124 |
11% |
Three Axles or more |
157 |
14% |
Axles Unknown |
2 |
0% |
Combination Trucks |
Truck Tractor − Bobtail |
29 |
3% |
Truck pulling Trailer(s) |
40 |
4% |
Tractor pulling Trailer |
697 |
62% |
Tractor pulling Two Trailers |
54 |
5% |
Other/Unknown/Missing |
Other/Unknown/Missing |
20 |
2% |
Total |
1,123 |
100% |
Table 6: All Trucks by Cargo Body Type
This table shows the number of trucks in the study sample cases by type of truck cargo body.
†
Cargo Body Type |
Crash Count |
Percentage |
Van |
515 |
46% |
Closed van |
383 |
34% |
Refrigerated van |
105 |
9% |
Open top van |
27 |
2% |
Dump |
184 |
16% |
Dump (rear) |
164 |
15% |
Bottom dump/hopper bottom |
20 |
2% |
Flatbed |
163 |
15% |
Flatbed |
122 |
11% |
Flatbed with sides |
21 |
2% |
Low boy |
11 |
1% |
Flatbed with equipment |
9 |
1% |
Tank |
71 |
6% |
Tank-liquid |
56 |
5% |
Tank-dry bulk |
14 |
1% |
Tank-compressed gas |
1 |
0% |
Other |
190 |
17% |
Garbage/refuse |
44 |
4% |
Cement mixer |
24 |
2% |
Pole/logging |
12 |
1% |
Auto carrier |
6 |
1% |
Livestock carrier |
5 |
0% |
Other − includes tow trucks, etc. |
49 |
4% |
Bobtail Unit − no cargo body |
28 |
3% |
Not Inspected/Unknown |
22 |
2% |
Total |
1,123 |
100% |
Table 7: All Trucks by Pre-Crash Movement
This table shows the number of trucks in the study sample cases by pre-crash movement of each truck.
†
PreCrash Movement |
Number |
Percentage |
Traveling in Lane |
803 |
72% |
Going Straight at steady speed |
609 |
54% |
Stopped in traffic lane |
109 |
10% |
Decelerating in traffic lane |
59 |
5% |
Accelerating in traffic lane |
19 |
2% |
Starting in traffic lane |
7 |
1% |
Negotiating a Curve |
168 |
15% |
Turning |
35 |
3% |
Turning left |
19 |
2% |
Turning right |
15 |
1% |
Making a U-turn |
1 |
0% |
Other |
117 |
10% |
Successful avoidance maneuver to a previous critical event |
40 |
4% |
Changing lanes |
33 |
3% |
Passing or overtaking another vehicle |
12 |
1% |
Merging |
7 |
1% |
Backing up (other than for parking position) |
6 |
1% |
Disabled or parked in travel lane |
1 |
0% |
No driver present1 |
11 |
1% |
Other |
6 |
1% |
Unknown |
1 |
0% |
Total |
1,123 |
100% |
Notes:
1 Examples of "No driver present"
include:
- A driver outside his disabled truck which was then struck from behind,
- A driver outside his truck which had previously suffered a rollover and
was then struck in the undercarriage by a passenger vehicle,
- A driverless truck being towed counted as one of the vehicles in the crash.
Table 8: All Trucks by Critical Pre-Crash Event
This table shows the number of trucks in the study sample cases by critical pre-crash event.
The critical pre-crash event is the event which made the crash unavoidable.
†
Critical Pre-Crash Event |
Number |
Percentage |
Vehicle Loss-of-Control Due to: |
145 |
13% |
Blow out/flat tire |
7 |
1% |
Disabling vehicle failure (e.g. wheel fell off) |
7 |
1% |
Non-disabling vehicle problem (e.g. hood flew up) |
5 |
0% |
Poor road conditions (Puddle, pot hole, ice, etc.) |
5 |
0% |
Traveling too fast for conditions |
86 |
8% |
Jackknife Event |
12 |
1% |
Cargo Shift |
13 |
1% |
Other cause of control loss |
10 |
1% |
Vehicle Traveling: |
239 |
21% |
Over the lane line on left side of travel lane |
43 |
4% |
Over the lane line on right side of travel lane |
30 |
3% |
Off the edge of the road on the left side |
28 |
3% |
Off the edge of the road on the right side |
60 |
5% |
End departure |
1 |
0% |
Turning left at intersection |
28 |
3% |
Turning right at intersection |
19 |
2% |
Crossing over (passing through) intersection |
26 |
2% |
This vehicle decelerating |
4 |
0% |
Other Motor Vehicle in Lane: |
283 |
25% |
Other vehicle stopped |
68 |
6% |
Traveling in same direction with low steady speed |
29 |
3% |
Traveling in same direction while decelerating |
49 |
4% |
Traveling in same direction with higher speed |
123 |
11% |
Traveling in opposite direction |
13 |
1% |
In crossover |
1 |
0% |
Other Motor Vehicle Encroaching into Lane From: |
233 |
21% |
Adjacent lane (same direction) − over left lane line |
43 |
4% |
Adjacent lane (same direction) − over right lane line |
53 |
5% |
Opposite direction − over left lane line |
70 |
6% |
Opposite direction − over right lane line |
1 |
0% |
Crossing street − turning into same direction |
1 |
0% |
Crossing street − across path |
46 |
4% |
Crossing street − turning into opposite direction |
15 |
1% |
Driveway − turning into same direction |
1 |
0% |
Driveway − across path |
1 |
0% |
Driveway − turning into opposite direction |
2 |
0% |
Pedestrian, Pedalcyclist, or other NonMotorist: |
31 |
3% |
Pedestrian in roadway |
24 |
2% |
Pedestrian approaching roadway |
1 |
0% |
Pedalcyclist or other nonmotorist in roadway |
6 |
1% |
Object or Animal: |
5 |
0% |
Animal in roadway |
1 |
0% |
Object in roadway |
4 |
0% |
Other: |
187 |
17% |
Not involved first harmful event1 |
163 |
15% |
Other |
24 |
2% |
Total |
1,123 |
100% |
Notes:
1 Cases categorized as "Not involved first harmful event" are those in which the truck was not
involved in the first harmful event in the crash sequence.
The term First Harmful Event refers to the first event of the crash to cause damage or injury.
Weighted Data
††(Source: Large Truck Crash Causation Study (October 2005) - Weighted Data)
During the three-year study period of the project, FMCSA estimated that there were approximately 141,000 large trucks involved in fatal, incapacitating, and non-incapacitating injury crashes. Each of the 963 LTCCS study cases was assigned a sampling weight (based on the probability of selection into the sample for the site associated with the case) that allows for national estimates of total truck crashes, broken down by various characteristics for these 141,000 trucks.
The summary tables in the following section illustrate the weighted results for the subject areas presented. The estimates presented may differ from true values because they are based on a probability sample of crashes and not a census of all crashes. The size of these differences may vary depending on which sample of the crashes is the focus of each particular table and analysis.
Notes:
- Percentages are rounded to the nearest whole number with values less than .5 percent rounded to zero.
- Totals and sub-totals are summed using unrounded estimates; therefore they may not appear to equal the sum of the relevant variables.
- Weighted data numbers are rounded to the nearest 1000.
Table 9: All Trucks by Crash Type
This table gives the weighted number of vehicles in study sample cases by crash configuration. In determining crash configuration crashes are first categorized by Vehicle Count – one vehicle, two vehicles, or three or more vehicles.
The term Passenger Vehicle refers to automobiles, pickup trucks, vans, and sport utility vehicles. The term Other includes buses, motorcycles, and construction equipment other than trucks. For crashes involving three or more vehicles, the crash configurations are determined by the first two vehicles to collide.
Crash Configuration Other includes all trucks not involved in the initial collision.
††
Vehicle Count |
Critical Pre-Crash Event |
Number |
Percentage |
1 |
Truck Only |
38,000 |
27% |
2 |
Truck-Passenger Vehicle |
50,000 |
35% |
2 |
Truck-Truck |
14,000 |
10% |
2 |
Truck-Other Vehicle |
1,000 |
1% |
3+ |
Truck-Passenger Vehicle |
15,000 |
11% |
3+ |
Truck-Truck |
8,000 |
6% |
3+ |
Truck-Other Vehicle |
*** |
0% |
3+ |
Other |
15,000 |
11% |
Total |
|
141,000 |
100% |
Notes: *** Weighted numbers lower than 500 are rounded to zero.
Table 10: All Trucks by Driver Age
This table shows the estimated number of trucks involved in study sample cases nation-wide by age of driver.
††
Age Category |
Number |
Percentage |
16 – 20 |
1,000 |
1% |
21 – 24 |
6,000 |
4% |
25 – 29 |
13,000 |
9% |
30 – 34 |
17,000 |
12% |
35 – 39 |
19,000 |
14% |
40 – 44 |
19,000 |
13% |
45 – 49 |
26,000 |
19% |
50 – 54 |
17,000 |
12% |
55 – 59 |
9,000 |
7% |
60 – 64 |
5,000 |
3% |
65 – 69 |
4,000 |
3% |
Seventy or Older |
1,000 |
1% |
Age Unknown |
4,000 |
3% |
Total |
141,000 |
100% |
Table 11: All Trucks by Critical Pre-Crash Event
This table shows the estimated number of trucks involved in crashes nation-wide. Counts of trucks are organized by the critical pre-crash event. The critical pre-crash event is the event which made the crash unavoidable.
††
Critical Pre-Crash Event |
Number |
Percentage |
Vehicle Loss-of-Control Due to: |
22,000 |
16% |
Blow out/flat tire, (specify blow out/flat, location/make) |
1,000 |
1% |
Disabling vehicle failure (e.g., wheel fell off) |
1,000 |
1% |
Non-disabling vehicle problem (e.g., hood flew up) |
*** |
0% |
Poor road conditions (Puddle, pot hole, ice, etc.) |
*** |
0% |
Traveling too fast for conditions |
14,000 |
10% |
Jackknife Event |
1,000 |
1% |
Cargo Shift |
2,000 |
2% |
Other cause of control loss |
1,000 |
1% |
Vehicle Traveling: |
35,000 |
25% |
Over the lane line on left side of travel lane |
5,000 |
4% |
Over the lane line on right side of travel lane |
5,000 |
4% |
Off the edge of the road on the left side |
6,000 |
4% |
Off the edge of the road on the right side |
9,000 |
7% |
End departure |
*** |
0% |
Turning left at intersection |
3,000 |
2% |
Turning right at intersection |
2,000 |
1% |
Crossing over (passing through) intersection |
5,000 |
4% |
This vehicle decelerating |
1,000 |
0% |
Other Motor Vehicle in Lane: |
35,000 |
25% |
Other vehicle stopped |
8,000 |
6% |
Traveling in same direction with low steady speed |
3,000 |
2% |
Traveling in same direction while decelerating |
6,000 |
4% |
Traveling in same direction with higher speed |
13,000 |
9% |
Traveling in opposite direction |
4,000 |
3% |
In crossover |
*** |
0% |
Other Motor Vehicle Encroaching into Lane From: |
24,000 |
17% |
Adjacent lane (same direction) − over left lane line |
5,000 |
4% |
Adjacent lane (same direction) − over right lane line |
7,000 |
5% |
Opposite direction − over left lane line |
6,000 |
4% |
Opposite direction − over right lane line |
*** |
0% |
Crossing street − turning into same direction |
*** |
0% |
Crossing street − across path |
4,000 |
3% |
Crossing street − turning into opposite direction |
2,000 |
1% |
Driveway − turning into same direction |
*** |
0% |
Driveway − across path |
*** |
0% |
Driveway − turning into opposite direction |
*** |
0% |
Pedestrian, Pedalcyclist, or other NonMotorist: |
2,000 |
2% |
Pedestrian in roadway |
1,000 |
1% |
Pedestrian approaching roadway |
*** |
0% |
Pedalcyclist or other nonmotorist in roadway |
1,000 |
0% |
Object or Animal: |
1,000 |
1% |
Animal in roadway |
*** |
0% |
Object in roadway |
1,000 |
0% |
Other: |
22,000 |
15% |
Not involved first harmful event1 |
20,000 |
14% |
Other |
2,000 |
1% |
Total |
141,000 |
100% |
Notes: *** Weighted numbers lower than 500 are rounded to zero.
1 Cases categorized as "Not involved first harmful event" are those in which the truck
was not involved in the first harmful event in the crash sequence. The term First Harmful Event refers to the first event of the crash to cause damage or injury.
Table 12: All Trucks by Critical Pre-Crash Event - Trucks Assigned Critical Reason
This table shows the estimated number of trucks involved in crashes nation-wide, in which the truck was assigned the critical reason for the crash. Counts of trucks are organized by the critical pre-crash event. The critical pre-crash event is the event which made the crash unavoidable.
††
Critical Pre-Crash Event |
Number |
Percentage |
Vehicle Loss-of-Control Due to: |
22,000 |
28% |
Blow out/flat tire, (specify blow out/flat, location/make) |
1,000 |
1% |
Disabling vehicle failure (e.g., wheel fell off) |
1,000 |
2% |
Non-disabling vehicle problem (e.g. hood flew up) |
*** |
0% |
Poor road conditions (Puddle, pot hole, ice, etc.) |
*** |
0% |
Traveling too fast for conditions |
14,000 |
18% |
Jackknife Event |
1,000 |
2% |
Cargo Shift |
2,000 |
3% |
Other cause of control loss |
1,000 |
2% |
Vehicle Traveling: |
33,000 |
43% |
Over the lane line on left side of travel lane |
5,000 |
7% |
Over the lane line on right side of travel lane |
5,000 |
6% |
Off the edge of the road on the left side |
6,000 |
7% |
Off the edge of the road on the right side |
9,000 |
12% |
End departure |
*** |
0% |
Turning left at intersection |
2,000 |
3% |
Turning right at intersection |
1,000 |
1% |
Crossing over (passing through) intersection |
5,000 |
6% |
This vehicle decelerating |
*** |
0% |
Other Motor Vehicle in Lane: |
17,000 |
22% |
Other vehicle stopped |
8,000 |
11% |
Traveling in same direction with low steady speed |
3,000 |
4% |
Traveling in same direction while decelerating |
5,000 |
7% |
Traveling in same direction with higher speed |
*** |
0% |
Traveling in opposite direction |
*** |
0% |
Other Motor Vehicle Encroaching into Lane From: |
1,000 |
1% |
Adjacent lane (same direction) − over left lane line |
1,000 |
1% |
Adjacent lane (same direction) − over right lane line |
*** |
0% |
Crossing street − across path |
*** |
0% |
Crossing street − turning into opposite direction |
*** |
0% |
Driveway − turning into opposite direction |
*** |
0% |
Pedestrian, Pedalcyclist, or other NonMotorist: |
1,000 |
2% |
Pedestrian in roadway |
1,000 |
1% |
Pedalcyclist or other nonmotorist in roadway |
1,000 |
1% |
Object or Animal: |
1,000 |
1% |
Animal in roadway |
*** |
0% |
Object in roadway |
1,000 |
1% |
Other: |
2,000 |
3% |
Not involved first harmful event1 |
*** |
1% |
Other |
2,000 |
2% |
Total |
78,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
1 Cases categorized as "Not involved first harmful event" are those in which the truck
was not involved in the first harmful event in the crash sequence. The term First
Harmful Event refers to the first damage or injury-producing event in the crash.
Table 13: All Trucks by Critical Reason
This table shows the estimated number of trucks involved in crashes nation-wide, in which the truck was assigned the critical reason for the crash. Counts of trucks are organized by critical reason.
††
Critical Reason |
Number |
Percentage |
Physical Driver Factor |
9,000 |
12% |
Sleep, that is, actually asleep |
5,000 |
7% |
Heart attack or other physical impairment of ability to act |
3,000 |
4% |
Other critical non-performance |
*** |
0% |
Unknown critical non-performance |
*** |
1% |
Driver Recognition Factor |
22,000 |
29% |
Inattention (i.e. daydreaming) |
5,000 |
6% |
Internal distraction |
3,000 |
3% |
External distraction |
2,000 |
3% |
Inadequate surveillance |
9,000 |
12% |
Unknown recognition error |
4,000 |
5% |
Driver Decision Factor |
30,000 |
38% |
Too fast for conditions to be able to respond to unexpected actions of other road users |
7,000 |
9% |
Misjudgment of gap or other's speed |
2,000 |
3% |
Following too closely to respond to unexpected actions |
3,000 |
4% |
False assumption of other road user's actions |
1,000 |
2% |
Illegal maneuver |
4,000 |
5% |
Inadequate evasive action, e.g. braking only, not braking and Steering |
1,000 |
1% |
Aggressive driving behavior |
1,000 |
1% |
Too fast for curve/turn |
9,000 |
12% |
Other Decision Factors |
1,000 |
1% |
Unknown decision error |
*** |
0% |
Driver Performance Factor |
4,000 |
6% |
Panic/Freezing |
*** |
0% |
Overcompensation |
2,000 |
3% |
Poor directional control, e.g. failing to control vehicle with skill ordinarily expected |
2,000 |
3% |
Unknown Driver Error |
3,000 |
4% |
Vehicle Related Factor |
8,000 |
10% |
Tires/wheels failed |
1,000 |
1% |
Brakes failed |
1,000 |
1% |
Steering failed |
*** |
0% |
Cargo shifted |
3,000 |
4% |
Trailer attachment failed |
*** |
0% |
Suspension failed |
1,000 |
1% |
Body, doors, hood failed |
*** |
0% |
Degraded braking capability |
2,000 |
3% |
Transmission/engine failure |
*** |
0% |
Other vehicle failure |
*** |
0% |
Environment − Highway |
2,000 |
2% |
Signs/signals missing |
1,000 |
1% |
Road design − roadway geometry (e.g. ramp curvature) |
*** |
0% |
Road design − Other |
*** |
1% |
Slick roads (low friction road surface due to ice, loose debris, any other cause) |
*** |
1% |
Environment − Weather |
*** |
0% |
Fog |
*** |
0% |
Wind gust |
*** |
0% |
Glare |
*** |
0% |
Unknown reason for critical event |
*** |
0% |
Total |
78,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 14: All Trucks by Associated Factors
This table shows the estimated number of trucks involved in crashes nation-wide by specific factors associated with the particular crash in which that truck was involved.
††
Associated Factor |
Number |
Percentage |
Driver |
Prescription Drug Use |
37,000 |
26% |
Traveling Too Fast For Conditions |
33,000 |
23% |
Unfamiliar with Roadway |
31,000 |
22% |
Over-the-Counter Drug Use |
25,000 |
18% |
Inadequate Surveillance |
20,000 |
14% |
Fatigue |
18,000 |
13% |
Illegal Maneuver |
13,000 |
9% |
Inattention |
12,000 |
9% |
Exterior Distraction |
11,000 |
8% |
Inadequate Evasive Action |
9,000 |
7% |
Aggressive Driving Behavior |
9,000 |
7% |
Unfamiliar with Vehicle |
9,000 |
7% |
Following Too Closely |
7,000 |
5% |
False Assumption of Others’ Actions |
7,000 |
5% |
Under Pressure to Accept Additional Loads |
6,000 |
4% |
Conversation |
5,000 |
4% |
Under Pressure to Operate Even If Fatigued |
4,000 |
3% |
Misjudgment of Gap Distance |
4,000 |
3% |
In a Hurry Prior to Crash |
4,000 |
3% |
Illness |
4,000 |
3% |
Interior Distraction |
3,000 |
2% |
Illegal Drug Use |
3,000 |
2% |
Uncomfortable with Some Aspect of Vehicle or Load |
4,000 |
3% |
Self Induced Legal Work Pressure |
3,000 |
2% |
Required to Accept Short Notice Trips |
3,000 |
2% |
Work Schedule Pressure |
3,000 |
2% |
Upset Prior to Crash |
3,000 |
2% |
Alcohol Use |
1,000 |
1% |
Other Decision Factors − includes proceeding with obstructed view, stopping when not required to, and failing to yield, as well as others |
13,000 |
9% |
Other Physical Factors − includes hearing problems, prosthesis, paraplegia, strenuous activities, sleep apnea, as well as others |
11,000 |
8% |
Other Motor Carrier Work Pressure |
9,000 |
6% |
Other Recognition Factors − includes impending problem masked by traffic flow pattern, driver focused on extraneous vehicle, and other recognition error |
4,000 |
3% |
Other Emotional Factors − includes clinical depression |
1,000 |
1% |
Vehicle |
Brake Deficiency |
37,000 |
26% |
Tire Deficiency |
7,000 |
5% |
Jackknife Event |
7,000 |
5% |
Overweight |
7,000 |
5% |
Cargo Shift |
6,000 |
4% |
Light Failure |
5,000 |
3% |
Brake Failure |
5,000 |
3% |
Cargo Securement |
4,000 |
3% |
Vehicle View Obstruction − includes obstruction related to load, vehicle design, or other factor |
2,000 |
1% |
Engine, Fuel System, or Exhaust Deficiency |
2,000 |
1% |
Transmission Failure |
1,000 |
1% |
Tire Failure |
1,000 |
1% |
Reflective Tape Missing/Obscured |
1,000 |
1% |
All Other Defects − includes suspension frame deficiency, and towing unit problem |
5,000 |
4% |
Environment |
Traffic Flow Interruption − includes work zones, roadway immersion, prior crash, and traffic congestion |
40,000 |
28% |
Roadway Related Factors |
29,000 |
20% |
Stop Required Prior to Crash − includes stop required for traffic control device, and yield right of way requirement |
28,000 |
20% |
Weather Related Factors |
20,000 |
14% |
Sight Obstructed by Road/Other Vehicle |
6,000 |
4% |
Other Traffic/Vehicle Factors − includes any factors not listed causing the driver to feel uncomfortable with surrounding traffic or the vehicle |
7,000 |
5% |
Other Vehicle Obscured (by Glare/Headlights, etc) |
2,000 |
2% |
Other Environmental Factors |
1,000 |
0% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 15: Trucks and Passenger Vehicles by Critical Pre-Crash Event - Vehicles Assigned Critical Reason
This table shows the estimated number of trucks and passenger vehicles involved in crashes nation-wide in which the truck or passenger vehicle was assigned the critical reason. Counts of vehicles are organized by critical pre-crash event. The critical pre-crash event is the event which made the crash unavoidable.
††
Critical Pre-Crash Event |
Truck |
Passenger Vehicle |
Number |
Percentage |
Number |
Percentage |
Vehicle Loss-of-Control Due to: |
3,000 |
10% |
6,000 |
16% |
Blow out/flat tire |
*** |
1% |
1,000 |
2% |
Disabling vehicle failure (e.g. wheel fell off) |
*** |
0% |
0 |
0% |
Non-disabling vehicle problem (e.g. hood flew up) |
*** |
0% |
0 |
0% |
Poor road conditions (Puddle, pot hole, ice, etc.) |
*** |
0% |
*** |
1% |
Traveling too fast for conditions |
2,000 |
7% |
2,000 |
6% |
Jackknife Event |
1,000 |
2% |
0 |
0% |
Other cause of control loss |
*** |
0% |
2,000 |
5% |
Unknown cause of control loss |
0 |
0% |
1,000 |
2% |
Vehicle Traveling: |
13,000 |
46% |
21,000 |
58% |
Over the lane line on left side of travel lane |
4,000 |
13% |
10,000 |
27% |
Over the lane line on right side of travel lane |
3,000 |
11% |
2,000 |
4% |
Off the edge of the road on the left side |
*** |
0% |
2,000 |
5% |
Off the edge of the road on the right side |
*** |
1% |
1,000 |
2% |
Turning left at intersection |
2,000 |
6% |
4,000 |
10% |
Turning right at intersection |
1,000 |
3% |
*** |
1% |
Crossing over (passing through) intersection |
3,000 |
12% |
3,000 |
9% |
This vehicle decelerating |
*** |
0% |
*** |
0% |
Other Motor Vehicle in Lane: |
11,000 |
38% |
8,000 |
23% |
Other vehicle stopped |
7,000 |
24% |
3,000 |
7% |
Traveling in same direction with low steady speed |
1,000 |
3% |
3,000 |
9% |
Traveling in same direction while decelerating |
3,000 |
10% |
2,000 |
5% |
Traveling in same direction with higher speed |
*** |
0% |
1,000 |
2% |
Traveling in opposite direction |
*** |
1% |
*** |
0% |
Other Motor Vehicle Encroaching into Lane From: |
*** |
2% |
1,000 |
2% |
Adjacent lane (same direction) − over left lane line |
0 |
0% |
*** |
0% |
Adjacent lane (same direction) − over right lane line |
*** |
0% |
0 |
0% |
Opposite direction − over left lane line |
0 |
0% |
*** |
1% |
Crossing street, turning into same direction |
0 |
0% |
*** |
1% |
Crossing street, across path |
*** |
0% |
0 |
0% |
Crossing street, turning into opposite direction |
*** |
1% |
0 |
0% |
Driveway, across path |
0 |
0% |
*** |
0% |
Driveway, turning into opposite direction |
*** |
1% |
*** |
0% |
Object or Animal: |
0 |
0% |
*** |
0% |
Object in roadway |
0 |
0% |
*** |
0% |
Other: |
1,000 |
5% |
1,000 |
2% |
Not involved first harmful event1 |
*** |
0% |
0 |
0% |
Other |
1,000 |
4% |
1,000 |
2% |
Total |
29,000 |
100% |
37,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
1 Cases categorized as "Not involved first harmful event" are those in which the truck
was not involved in the first harmful event in the crash sequence. The term First Harmful Event refers to the first event of the crash to cause damage or injury.
Table 16: Trucks and Passenger Vehicles by Critical Reason
This table shows the estimated number of trucks and passenger vehicles involved in crashes nation-wide in which the truck or passenger vehicle was assigned the critical reason. Counts of vehicles are organized by critical reason.
††
This table shows the estimated number of trucks and passenger vehicles involved in crashes nation-wide in which the truck or passenger vehicle was assigned the critical reason for the crash and grouped by critical reason. All numbers for weighted data are rounded to the nearest 1000. Percentages are calculated to unrounded estimates. Totals and sub-totals are summed using unrounded estimates; therefore they may not appear to equal the sum of the relevant variables.
|
Critical Reason |
Truck |
Passenger Vehicle |
Number |
Percentage |
Number |
Percentage |
Physical Driver Factor |
1,000 |
3% |
6,000 |
16% |
Sleep, that is, actually asleep |
*** |
0% |
4,000 |
10% |
Heart attack or other physical impairment of ability to act |
1,000 |
3% |
2,000 |
6% |
Other critical non-performance |
*** |
0% |
0 |
0% |
Unknown critical non-performance |
0 |
0% |
*** |
0% |
Driver Recognition Factor |
10,000 |
35% |
11,000 |
30% |
Inattention (i.e. daydreaming) |
2,000 |
7% |
2,000 |
4% |
Internal distraction |
1,000 |
3% |
3,000 |
9% |
External distraction |
2,000 |
6% |
1,000 |
2% |
Inadequate surveillance |
5,000 |
19% |
4,000 |
11% |
Other recognition error |
0 |
0% |
*** |
1% |
Unknown recognition error |
*** |
1% |
1,000 |
4% |
Driver Decision Factor |
12,000 |
43% |
9,000 |
24% |
Too fast for conditions to be able to respond to unexpected actions of other road users |
4,000 |
13% |
3,000 |
7% |
Too slow for traffic stream |
0 |
0% |
*** |
0% |
Misjudgment of gap or other's speed |
1,000 |
5% |
2,000 |
4% |
Following too closely to respond to unexpected actions |
2,000 |
6% |
*** |
1% |
False assumption of other road user's actions |
1,000 |
3% |
1,000 |
2% |
Illegal maneuver |
3,000 |
9% |
3,000 |
7% |
Inadequate evasive action, e.g. braking only, not braking and steering |
*** |
1% |
*** |
0% |
Aggressive driving behavior |
*** |
0% |
*** |
1% |
Too fast for curve/turn |
1,000 |
3% |
*** |
0% |
Other Decision Factors |
1,000 |
2% |
*** |
0% |
Unknown decision error |
0 |
0% |
*** |
0% |
Driver Performance Factor |
1,000 |
3% |
3,000 |
8% |
Panic/Freezing |
*** |
0% |
0 |
0% |
Overcompensation |
*** |
1% |
2,000 |
6% |
Poor directional control, e.g. failing to control vehicle with skill ordinarily expected |
*** |
2% |
1,000 |
3% |
Unknown performance error |
0 |
0% |
*** |
0% |
Unknown Driver Error |
1,000 |
4% |
3,000 |
10% |
Vehicle Related Factor |
2,000 |
8% |
2,000 |
4% |
Tires/wheels failed |
*** |
1% |
1,000 |
2% |
Brakes failed |
*** |
1% |
*** |
0% |
Cargo shifted |
*** |
1% |
0 |
0% |
Trailer attachment failed |
*** |
0% |
0 |
0% |
Degraded braking capability |
2,000 |
5% |
0 |
0% |
Transmission/engine failure |
0 |
0% |
*** |
0% |
Other vehicle failure |
0 |
0% |
*** |
1% |
Unknown vehicle failures |
0 |
0% |
*** |
0% |
Environment - Highway |
1,000 |
3% |
*** |
1% |
Signs/signals missing |
1,000 |
3% |
0 |
0% |
View obstructed by other vehicles |
0 |
0% |
*** |
0% |
Slick roads (low friction road surface due to ice, loose debris, any other cause) |
*** |
1% |
*** |
1% |
Environment - Weather |
*** |
0% |
1,000 |
2% |
Wind gust |
0 |
0% |
*** |
0% |
Glare |
*** |
0% |
1,000 |
1% |
Unknown reason for critical event |
*** |
0% |
2,000 |
4% |
Total |
29,000 |
100% |
37,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 17: Trucks and Passenger Vehicles by Associated Factors
This table shows the estimated number of trucks and passenger vehicles involved in crashes nation-wide by specific factors associated with the particular crash.
††
Associated Factor |
Truck |
Passenger Vehicle |
Number |
Percentage |
Number |
Percentage |
Driver |
Prescription Drug Use |
19,000 |
29% |
23,000 |
35% |
Over-the-Counter Drug Use |
13,000 |
20% |
7,000 |
11% |
Unfamiliar with Roadway |
13,000 |
19% |
6,000 |
10% |
Inadequate Surveillance |
11,000 |
16% |
9,000 |
14% |
Traveling Too Fast For Conditions |
10,000 |
15% |
7,000 |
11% |
Illegal Maneuver |
8,000 |
12% |
9,000 |
13% |
Inattention |
6,000 |
9% |
6,000 |
9% |
Exterior Distraction |
5,000 |
8% |
4,000 |
6% |
Fatigue |
5,000 |
7% |
10,000 |
15% |
Inadequate Evasive Action |
4,000 |
7% |
5,000 |
7% |
False Assumption of Others Actions |
4,000 |
6% |
2,000 |
3% |
Unfamiliar with Vehicle |
4,000 |
5% |
2,000 |
2% |
Following Too Closely |
3,000 |
5% |
1,000 |
1% |
Aggressive Driving Behavior |
3,000 |
5% |
6,000 |
9% |
Misjudgment of Gap Distance |
3,000 |
4% |
2,000 |
4% |
Self Induced Legal Work Pressure |
2,000 |
4% |
1,000 |
1% |
Under Pressure to Accept Additional Loads |
2,000 |
4% |
0 |
0% |
Required to Accept Short Notice Trips |
2,000 |
3% |
0 |
0% |
Interior Distraction |
2,000 |
2% |
3,000 |
5% |
Driver Upset Prior to Crash |
1,000 |
2% |
3,000 |
5% |
Driver in a Hurry Prior to Crash |
1,000 |
2% |
3,000 |
4% |
Under Pressure to Operate Even If Fatigued |
1,000 |
2% |
0 |
0% |
Conversation |
1,000 |
2% |
2,000 |
3% |
Illness |
1,000 |
1% |
5,000 |
8% |
Illegal Drug Use |
*** |
0% |
4,000 |
7% |
Alcohol Use |
*** |
0% |
6,000 |
9% |
Other Physical Factors − includes hearing problems, prosthesis, paraplegia, strenuous activities, sleep apnea, as well as others |
6,000 |
9% |
6,000 |
8% |
Other Motor Carrier Work Pressure |
5,000 |
7% |
*** |
0% |
Other Decision Factors − includes proceeding with obstructed view, stopping when not required to, and failing to yield, as well as others |
4,000 |
6% |
5,000 |
8% |
Other Recognition Factors − includes impending problem masked by traffic flow pattern, driver focused on extraneous vehicle, and other recognition error |
3,000 |
4% |
2,000 |
3% |
Other Emotional Factors − includes clinical depression |
1,000 |
1% |
3,000 |
5% |
Vehicle |
Brake Deficiency |
16,000 |
25% |
1,000 |
2% |
Tire Deficiency |
4,000 |
6% |
1,000 |
2% |
Overweight |
3,000 |
5% |
*** |
0% |
Light Deficiency |
3,000 |
5% |
1,000 |
1% |
Jackknife Event |
2,000 |
4% |
0 |
0% |
Vehicle View Obstruction − includes obstruction related to load, vehicle design, or other factor |
2,000 |
3% |
1,000 |
1% |
Brake Failure |
1,000 |
1% |
*** |
2% |
Engine, Fuel System, or Exhaust Deficiency |
1,000 |
2% |
*** |
0% |
Reflective Tape Missing/Obscured |
1,000 |
1% |
0 |
0% |
Transmission Failure |
*** |
1% |
1,000 |
1% |
Cargo Securement |
*** |
1% |
*** |
0% |
Cargo Shift |
*** |
1% |
0 |
0% |
Tire Failure |
*** |
0% |
1,000 |
1% |
All Other Defects − includes suspension frame deficiency, and towing unit problem |
2,000 |
2% |
1,000 |
1% |
Environment |
Traffic Flow Interruption − includes work zones, roadway immersion, prior crash, and traffic congestion. |
16,000 |
24% |
16,000 |
25% |
Stop Required Prior to Crash − includes stop required for traffic control device, and yield right of way requirement. |
14,000 |
21% |
16,000 |
25% |
Roadway Related Factors |
11,000 |
16% |
10,000 |
16% |
Weather Related Factors |
9,000 |
14% |
9,000 |
14% |
Sight Obstructed by Road/Other Vehicle |
5,000 |
7% |
3,000 |
5% |
Other Traffic/Vehicle Factors − includes any factors not listed causing the driver to feel uncomfortable with surrounding traffic or the vehicle |
2,000 |
4% |
2,000 |
3% |
Other Vehicle Obscured (by Glare/Headlights, etc) |
2,000 |
3% |
1,000 |
2% |
Other Environmental Factors |
*** |
1% |
1,000 |
1% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 18: Trucks in One-Vehicle Crashes by Critical Pre-Crash Event − Trucks Assigned Critical Reason
This table shows the estimated number of trucks nation-wide involved in one-vehicle crashes in which the truck was assigned the critical reason. Counts of trucks are organized by critical pre-crash event. The critical pre-crash event is the event which made the crash unavoidable.
††
Critical Pre-Crash Event |
Number |
Percentage |
Vehicle Loss-of-Control Due to: |
18,000 |
49% |
Blow out/flat tire |
*** |
1% |
Disabling vehicle failure (e.g. wheel fell off) |
1,000 |
3% |
Non-disabling vehicle problem (e.g. hood flew up) |
*** |
1% |
Poor road conditions (Puddle, pot hole, ice, etc.) |
*** |
1% |
Traveling too fast for conditions |
12,000 |
33% |
Jackknife Event |
*** |
1% |
Cargo Shift |
2,000 |
6% |
Other cause of control loss |
1,000 |
3% |
Vehicle Traveling: |
16,000 |
42% |
Over the lane line on left side of travel lane |
*** |
1% |
Over the lane line on right side of travel lane |
*** |
1% |
Off the edge of the road on the left side |
5,000 |
15% |
Off the edge of the road on the right side |
9,000 |
24% |
End departure |
*** |
0% |
Turning left at intersection |
*** |
1% |
Turning right at intersection |
*** |
1% |
Other Motor Vehicle in Lane: |
1,000 |
2% |
Traveling in same direction while decelerating |
1,000 |
2% |
Other Motor Vehicle Encroaching into Lane From: |
*** |
1% |
Adjacent lane (same direction) − over left lane line |
*** |
1% |
Adjacent lane (same direction) − over right lane line |
*** |
0% |
Pedestrian, Pedalcyclist, or other NonMotorist: |
1,000 |
3% |
Pedestrian in roadway |
*** |
1% |
Pedalcyclist or other nonmotorist in roadway |
1,000 |
2% |
Object or Animal: |
1,000 |
2% |
Animal in roadway |
*** |
1% |
Object in roadway |
*** |
1% |
Other: |
1,000 |
2% |
Other |
1,000 |
2% |
Total |
37,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 19: Trucks in One-Vehicle Crashes by Critical Reason
This table shows the estimated number of trucks nation-wide involved in one-vehicle crashes by critical reason
††
Critical Reason |
Number |
Percentage |
Physical Driver Factor: |
8,000 |
21% |
Sleep, that is, actually asleep |
5,000 |
13% |
Heart attack or other physical impairment of ability to act |
2,000 |
6% |
Other critical non-performance |
*** |
0% |
Unknown critical non-performance |
*** |
1% |
Driver Recognition Factor |
6,000 |
17% |
Inattention (i.e. daydreaming) |
2,000 |
6% |
Internal distraction |
1,000 |
4% |
External distraction |
*** |
1% |
Inadequate surveillance |
1,000 |
4% |
Unknown recognition error |
1,000 |
3% |
Driver Decision Factor |
13,000 |
34% |
Too fast for conditions to be able to respond to unexpected actions of other road users |
2,000 |
7% |
Misjudgment of gap or other's speed |
*** |
0% |
Following too closely to respond to unexpected actions |
*** |
0% |
Illegal maneuver |
*** |
0% |
Aggressive driving behavior |
1,000 |
2% |
Too fast for curve/turn |
9,000 |
23% |
Other Decision Factors |
*** |
1% |
Driver Performance Factor |
3,000 |
9% |
Overcompensation |
2,000 |
4% |
Poor directional control, e.g. failing to control vehicle with skill ordinarily expected |
2,000 |
4% |
Unknown Driver Error |
1,000 |
4% |
Vehicle Related Factor |
5,000 |
13% |
Tires/wheels failed |
*** |
1% |
Brakes failed |
*** |
1% |
Steering failed |
*** |
0% |
Cargo shifted |
3,000 |
7% |
Suspension failed |
1,000 |
2% |
Degraded braking capability |
1,000 |
2% |
Environment − Highway |
1,000 |
2% |
Road design − roadway geometry (e.g. ramp curvature) |
*** |
0% |
Road design − other |
*** |
1% |
Slick roads (low friction road surface due to ice, loose debris, any other cause) |
*** |
1% |
Environment − Weather |
*** |
0% |
Wind gust |
*** |
0% |
Unknown reason for critical event |
*** |
0% |
Total |
37,000 |
100% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
Table 20: Trucks in One-Vehicle Crashes by Associated Factors
This table shows the estimated number of trucks nation-wide involved in one-vehicle crashes by specific associated factor.
††
Associated Factor |
Number |
Percentage |
Driver |
Traveling Too Fast For Conditions |
18,000 |
48% |
Unfamiliar with Roadway |
11,000 |
30% |
Driver Fatigue |
11,000 |
28% |
Prescription Drug Use |
10,000 |
25% |
Over-the-Counter Drug Use |
7,000 |
18% |
Inattention |
5,000 |
12% |
Inadequate Surveillance |
4,000 |
10% |
External Distraction |
4,000 |
10% |
Aggressive Driving Behavior |
4,000 |
9% |
Inadequate Evasive Action |
3,000 |
8% |
Illness |
3,000 |
8% |
Conversation |
3,000 |
8% |
Uncomfortable with Some Aspect of Vehicle or Load |
3,000 |
7% |
Under Pressure to Operate Even If Fatigued |
2,000 |
7% |
Under Pressure to Accept additional Loads |
2,000 |
7% |
Unfamiliar with Vehicle |
2,000 |
7% |
In a Hurry Prior to Crash |
2,000 |
6% |
Illegal Drug Use |
2,000 |
6% |
Work Schedule Pressure |
2,000 |
4% |
Illegal Maneuver |
2,000 |
4% |
Upset Prior to Crash |
1,000 |
4% |
Interior Distraction |
1,000 |
3% |
New Position |
1,000 |
3% |
Alcohol Use |
1,000 |
2% |
Self Induced Legal Work Pressure |
1,000 |
2% |
Required to Accept Short Notice Trips |
1,000 |
2% |
Pressure to Accept Loads with Little or No Notice |
1,000 |
2% |
Following Too Closely |
1,000 |
2% |
Misjudgment of Gap Distance |
*** |
1% |
False Assumption of Others Actions |
*** |
0% |
Other Decision Factors − includes proceeding with obstructed view, stopping when not required to, and failing to yield, as well as others |
7,000 |
18% |
Other Physical Factors − includes hearing problems, prosthesis, paraplegia, strenuous activities, and sleep apnea |
3,000 |
9% |
Other Motor Carrier Work Pressure |
4,000 |
5% |
Other Recognition Factors − includes impending problem masked by traffic flow pattern, driver focused on extraneous vehicle, and other recognition error |
1,000 |
2% |
Other Emotional Factors − includes clinical depression |
*** |
1% |
Vehicle |
Brake Deficiency |
15,000 |
39% |
Cargo Shift |
5,000 |
14% |
Tire Deficiency |
3,000 |
8% |
Jackknife Event |
4,000 |
9% |
Cargo Securement |
3,000 |
8% |
Overweight |
3,000 |
7% |
Brake Failure |
2,000 |
5% |
Transmission Failure |
1,000 |
2% |
Tire Failure |
1,000 |
2% |
Engine, Fuel System, or Exhaust Deficiency |
*** |
1% |
View Obstruction − includes obstruction related to load, vehicle design, or other factor |
*** |
1% |
Light Deficiency |
*** |
0% |
All Other Defects − includes suspension frame deficiency, and towing unit problem |
3,000 |
7% |
Environment |
Roadway Related Factors |
10,000 |
26% |
Weather Related Factors |
4,000 |
11% |
Stop Required Prior to Crash − includes stop required for traffic control device, and yield right of way requirement |
4,000 |
10% |
Traffic Flow Interruption − includes work zones, roadway immersion, prior crash, and traffic congestion |
3,000 |
7% |
Sightline Obstructed |
1,000 |
2% |
Other Traffic/Vehicle Factors − includes any factors not listed causing the driver to feel uncomfortable with surrounding traffic or the vehicle |
3,000 |
7% |
Other Vehicle Obscured (by glare/headlights, etc) |
*** |
0% |
Other Environmental Factors |
*** |
0% |
Notes:
*** Weighted numbers lower than 500 are rounded to zero.
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