Index
Documentation Page
Summary
Background
Methods
Results
Countermeasures
Tri-Level Comparison
Reference

Recommendations For Countermeasures

Recommendations for countermeasures to reduce specific crash types fall into three major areas: Education/Training, Law Enforcement, and Technology-Based. While virtually all of the identified problem types could be addressed through either education or training countermeasures, Table 9 prioritizes countermeasures on the basis for which countermeasure type is likely to be most successful. For example, seven of the 23 identified problem types involve driver inattention as the primary factor associated with crash occurrence. This factor can be most effectively addressed though an education countermeasure that has a public information campaign as a central focus. The general public should be informed of the relative size of this problem in the crash population, the crash types that result from inattention, relevant situational factors, and the specific types of inattention mechanisms that lead to crash occurrence. Inattention is a pervasive problem among all age groups of both genders. Relatively few of the crash-involved drivers in this sample appeared to be aware that removing attention from the driving task for even brief periods could result in crash involvement. Similarly, focusing on internal thoughts was noted in each of the identified problem types. This would be very difficult to detect because the drivers were typically looking forward and may have appeared to be attentive to other drivers or witnesses. Following the crash occurrence, most of the drivers who were focusing on internal thoughts expressed in increased awareness of the relative risk associated with this attention problem. A public information campaign focussing on these types of issues would increase the awareness levels of non-crash involved drivers.

"The looked, did not see", "Accepted inadequate gap to other vehicle", and "Turned/crossed with obstructed view" problems could be most effectively addressed, in the near term, with driver training countermeasures that focus on appropriate traffic scanning/checking techniques. These training techniques should be incorporated into all driver education courses for new drivers. The perceptual difficulties associated with older drivers in these problems types could probably be most effectively addressed through low-level public information campaigns specifically targeted to this group.

The remaining problem types are best suited to enhanced law enforcement countermeasures. The relatively strong association between alcohol impairment and vehicle speed factors should be stressed in law enforcement countermeasure applications.

Table 9

Education/Training/Law Enforcement Countermeasures

   

Countermeasure Type

Crash Type/Problem Type

Problem Size (%)

Education

Training

Law Enforcement

Crash Type 3: Same Direction, Rear End

Problem Type 1: Driver Inattention-Mid Range

Travel Speeds

Problem Type 2: Driver Inattention-Low Range

Travel Speeds

Problem Type 3: Driver Inattention-High Range

Travel Speeds

Problem Type 4: Following Too Closely

5.6

2.5

2.4

2.4

X

X

X

 

 

 

 

 

 

X

 

 

 

 

 

 

X

Crash Type 4: Turn, Merge, Path Encroachment

Problem Type 1: Looked, Did Not See

Problem Type 2: Accepted Inadequate Gap

Problem Type 3: Turned With Obstructed View

Problem Type 4: Driver Inattention/TCD Violation

4.1

3.3

2.3

2.3

 

 

 

X

X

X

X

 

Crash Type 2: Single Driver, Roadside Departure

With Traction Loss

Problem Type 1: Excessive Vehicle Speed

Problem Type 2: DUI/DWI With Excessive

Vehicle Speed

Problem Type 3: DUI/DWI

 

2.3

1.6

1.6

   

 

X

X

X

Crash Type 1: Single Driver, Roadside Departure

Without Traction Loss

Problem Type 1: Driver Fatigue

Problem Type 2: Driver Inattention

Problem Type 3: DUI/DWI

 

1.7

1.6

1.5

 

X

X

 

 

 

 

X

Crash Type 6: Intersecting Paths, Straight Paths

Problem Type 1: Looked, Did Not See

Problem Type 2: Driver Inattention/TCD Violation

Problem Type 3: Crossed With Obstructed View

1.6

1.3

1.2

 

X

X

X

 

Crash Type 5: Same Trafficway, Opposite Direction

Problem Type 1: Driver Inattention

Problem Type 2: Lost Directional Control

Problem Type 3: Excessive Vehicle Speed

0.9

0.9

0.8

X

 

X

 

 

X

Crash Type 7: Other/Miscellaneous

Problem Type 1: Excessive Vehicle Speed

Problem Type 2: Following Too Closely

Problem Type 3: Sudden Deceleration

0.5

0.4

0.4

 

 

X

X

X

X

Total

43.2

     

Technology-based countermeasures are very likely to provide highly efficient solutions to the crash problem types identified in this report. It must be stressed, however, that the systems indicated in Table 10 are either currently in development or are undergoing product refinement/engineering evaluations and are unlikely to be available in the near term to appreciably diminish the relative magnitude of any given problem type. These solutions should be viewed as long term applications that will provide efficient solutions in a 5-15 year time frame.

Rear end crash avoidance systems (including headway detection units and smart cruise control units) will be applicable to all of the problem types identified in crash type 3 (Rear End Crashes) as well as a relatively high proportion of the crashes contained in problem types 2 and 3 of crash type 7 (Other/Miscellaneous Crashes). Intersection collision avoidance systems will be applicable to all of the problem types identified in crash type 4 (Turn, Merge, Path Encroachment) and in crash type 6 (Intersection Paths, Straight Paths). Lane keeping systems, on the other hand, will be applicable to all of the problem types identified in crash type 1 (Single Driver, Roadside Departure Without Traction Loss) as well as crashes in problem type 1 of crash type 5 (Same Trafficway, Opposite Direction).

Table 10

Technology-Based Countermeasures

   

Countermeasure Type

Crash Type/Problem Type

Problem Size (%)

Rear End Crash Avoidance Systems

Intersection Collision Avoidance Systems

Lane Keeping Systems

Crash Type 3: Same Direction, Rear End

Problem Type 1: Driver Inattention-Mid Range

Travel Speeds

Problem Type 2: Driver Inattention-Low Range

Travel Speeds

Problem Type 3: Driver Inattention-High Range

Travel Speeds

Problem Type 4: Following Too Closely

5.6

2.5

2.4

2.4

X

X

X

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Crash Type 4: Turn, Merge, Path Encroachment

Problem Type 1: Looked, Did Not See

Problem Type 2: Accepted Inadequate Gap

Problem Type 3: Turned With Obstructed View

Problem Type 4: Driver Inattention/TCD Violation

4.1

3.3

2.3

2.3

 

 

 

 

 

X

X

X

X

 

Crash Type 2: Single Driver, Roadside Departure

With Traction Loss

Problem Type 1: Excessive Vehicle Speed

Problem Type 2: DUI/DWI With Excessive

Vehicle Speed

Problem Type 3: DUI/DWI

 

2.3

1.6

1.6

   

 

 

Crash Type 1: Single Driver, Roadside Departure

Without Traction Loss

Problem Type 1: Driver Fatigue

Problem Type 2: Driver Inattention

Problem Type 3: DUI/DWI

 

1.7

1.6

1.5

   

 

X

X

X

Crash Type 6: Intersecting Paths, Straight Paths

Problem Type 1: Looked, Did Not See

Problem Type 2: Driver Inattention/TCD Violation

Problem Type 3: Crossed With Obstructed View

1.6

1.3

1.2

 

X

X

X

 

Crash Type 5: Same Trafficway, Opposite Direction

Problem Type 1: Driver Inattention

Problem Type 2: Lost Directional Control

Problem Type 3: Excessive Vehicle Speed

0.9

0.9

0.8

   

X

Crash Type 7: Other/Miscellaneous

Problem Type 1: Excessive Vehicle Speed

Problem Type 2: Following Too Closely

Problem Type 3: Sudden Deceleration

0.5

0.4

0.4

 

X

X

   

Total

43.2