CMF / CRF Details

CMF ID: 10211

Change from standard sized lanes to undersized lanes

Description: Convert from standard sized lanes (average lane width between 3.25 meters and 3.75 meters) to undersized lanes (average lane width less than 3.25 meters)

Prior Condition: Average lane width is between 3.25 meters and 3.75 meters

Category: Roadway

Study: Relationship between Lane Width and Safety along Urban Expressways in Shanghai, Wu et al., 2019

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 3.377
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: -237.7   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type: Other
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes: 4 to 8
Road Division Type: Divided by Median
Speed Limit: 80 km/h
Area Type: Urban
Traffic Volume: Minimum of 42785 to Maximum of 120001 Average Daily Traffic (ADT)
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2010 to 2013
Municipality: Shanghai
State:
Country: China
Type of Methodology Used: Regression cross-section
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-07-2019
Comments: This CMF applies to all crashes during non-congested flow on expressway segments between interchanges. Flow is considered non-congested when the average travel speed exceeds 40 km/h.