CMF / CRF Details
CMF ID: 4674
Decrease freeway ramp spacing from infinity to S (ft) with/without auxiliary lane
Description:
Decreasing ramp spacing (painted gore to painted gore) on freeway segments from infinity to S (ft) with or without exisiting auxiliary lane
Prior Condition: Ramp spacing approaching infinity, which represents a basic freeway segment with no ramps.
Category: Access management
| Crash Modification Factor (CMF) |
|---|
| Value: |  |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Crash Reduction Factor (CRF) |
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| Value: |  |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability |
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| Crash Type: | Not specified |
| Crash Severity: | All |
| Roadway Types: | Principal Arterial Interstate |
| 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 5,134 to Maximum of 153,500 Average Daily Traffic (ADT) |
| Average Traffic Volume: | 43,158 Average Daily Traffic (ADT) |
| Time of Day: | Not specified |
| 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: | 2006 to 2008 |
| Municipality: | |
| State: | CA,WA |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (site-years): | 1212 site-years |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | May 01, 2013 |
| Comments: | - CMF is function of ramp spacing (S) in ft. and existence of auxiliary lane (Auxln = 0 or 1)- See Studay possible bias for limitations. |
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