Appendix A – Highway Crash Reduction Factors

//Appendix A – Highway Crash Reduction Factors
Appendix A – Highway Crash Reduction Factors2018-02-28T18:16:21-05:00

Appendix A – Highway Crash Reduction Factors (CRF)

Improvement Type

Crash Reduction Factor

Definition

Score

Highway/Railroad Crossing

90

Improving existing highway and railroad crossing intersections primarily by constructing grade separations.

5

2 lane to 4 lane divided-rural

55

The upgrade of an existing 2-lane highway to a 4-lane divided facility to increase traffic flow. Widen 2 an existing divided highway to 4 lanes.

5

Arterial to Full Control

40

Upgrading a road serving major traffic movements (high-speed, high volume) for travel between major points to a limited access divided arterial highway.

5

Upgrade to Grade Separation

40

Improving an intersection by separating traffic through physical means such as an overpass to allow different flows of traffic.

5

Arterial to Partial Control

35

Upgrading a road serving major traffic movements (high-speed, high volume) for travel between major points to alleviate congestion and reduce impediments to traffic flow. Include indirect left turn or similar movements. Add access management

5

Access Consolidation

25

Replace TWTL with a divided median cross section with no additional capacity. Add non-traversible median. Access management.

3

Improve Intersection

25

Install turn lane (s), roundabout installation, horizontal realignment

3

Modernize Roadway

20

Realignment or reconstruction to bring geometric (vertical, horizontal) deficiencies up to modern standards. To include minor widening of lanes and shoulders, reconstruction, safety hazard eliminations, spot improvements

3

Install Two-way Left Turn lane

20

Widening existing pavement through addition of two way left turn lane. Typically used in areas where there appears to an issue with turning related crashes such as rear-end and head-on on two lane roads.

3

Realign Intersection

15

Improving the geometric configuration of multiple adjacent intersections (offset approaches) to enhance traffic flow. Reduce skew for intersections, convert two 3-leg intersections to a 4-leg intersection.

1

Add Closed Loop Signal System

15

Add coordinated closed loop signal system

1

Full  Control  to Interstate

10

Improving an existing freeway to interstate design standards primarily by increasing shoulder width and/or bridge clearances.

1

Auxiliary Lanes or Oper. Impr.

10

Add continuous auxiliary lane for weaving between entrance ramp and exit ramp or other interchange improvements.

1

Improve Interchange

10

Improving traffic flow at an existing interchange by changing the ramp configuration or type of interchange. Convert diamond to diverging diamond, modifying left-turn phasing on one intersection approach etc.

1

Add Lane to Full Control Fac.

10

The addition of a full lane of travel to an Interstate or existing full access controlled facility.

1

Ramp Metering

5

Add ramp meters

1

Add Signal System

5

New or upgraded signals

1

Construct Road in new location

0

Bypass, new route, new interchange, route relocation. Does not include construction of new local roadways.

0

Local Roadway Improvements

0

The minor widening, primarily increasing shoulder width etc., on local roads or the construction of a new local route to improve local transportation movements. Improvements to be made on county roads or city streets.

0

Install Cameras and DMS

0

Intelligent transportation system projects

0

Interchange Ramps

0

The addition of ramps to an existing grade separated interchange.

0

Maintenance Improvement

0

Drainage improvements, rock fall, landslides, rest area rehab, resurfacing, rock fall mitigation, signs, signals, weigh station rehab

0

Transportation Studies

0

Scoping studies, feasibility studies, PE & environmental, phase 1 design, small urban area, strategic corridor

0

Other improvement types

0

The upgrade of an existing two lane highway to a 4 lane divided facility to increase traffic flow. (urban)

0

2 lane to 4 lane divided-Urban

0

Any improvement types not included previously. Bike/ped, miscellaneous widening not specifically mentioned.

0

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