CMF / CRF Details
CMF ID: 9852
Raise posted speed
Description:
Prior Condition: Posted Speed Limit of 55 MPH or 60 MPH.
Category: Speed management
Study: In-Service Performance Evaluation of Median Cable Barriers in Iowa, Savolainen et al., 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 95 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.13 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.08 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -13 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 8 |
| Applicability | |
|---|---|
| Crash Type: | Cross median |
| Crash Severity: | All |
| Roadway Types: | Principal Arterial Other Freeways and Expressways |
| Street Type: | |
| Minimum Number of Lanes: | |
| Maximum Number of Lanes: | |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Not specified |
| Traffic Volume: | Minimum of 1832 to Maximum of 37580 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 10232 Annual Average Daily Traffic (AADT) |
| 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: | 2011 to 2015 |
| Municipality: | |
| State: | IA |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 1715 crashes |
| Sample Size (sites): | 3629 sites |
| Sample Size (site-years): | 18145 site-years |
| Sample Size (miles): | 1140 miles |
| Sample Size (mile-years): | 5700 mile-years |
