CMF / CRF Details

CMF ID: 5466

Landscape Medians at Intersections

Description: Landscape medians in form of ground cover, plant, or trees.

Prior Condition:  Medians with trees compliant with Florida’s design standards

Category: Access management

Study: Landscaping of Highway Medians at Intersections, Lin et al., 2013

Star Quality Rating:2 Stars  [View score details]
Rating Points Total:60
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.71
Crash Reduction Factor (CRF)
Value:-68  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:71
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:6
Number of Lanes Direction:
Number of Lanes Comment:2, 4, and 6 Lanes
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:30
Maximum Speed Limit:50
Speed Unit:mph
Speed Limit Comment:30 - 50 mph on Major Road / 15 - 30 mph on Minor Road
Area Type:Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day:Not specified
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:3-leg,4-leg
Traffic Control:Stop-controlled
Major Road Traffic Volume:Minimum of 4900 to Maximum of 49500 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2009 to 2010
Type of Methodology Used:Regression cross-section
Sample Size (crashes):174 crashes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Apr 30, 2014
Comments:The CMF represents the expected change in crashes for medians without trees compared to medians with trees compliant with Florida’s design standards. The state's design elements include tree setback, tree diameter, tree spacing, tree canopy, and ground cover.