CMF / CRF Details
CMF ID: 7569
Convert 2 lane roadway to 4 lane divided roadway
Description: Conversion of urban and rural two-lane roadways to four-lane divided roadways
Prior Condition: 2 lane roadway
Category: Roadway
Study: Evaluation of the Safety Effectiveness of the Conversion of Two-Lane Roadways to Four-Lane Divided Roadways: Bayesian vs. Empirical Bayes, Ahmed et al., 2015
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 125 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.712 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.076 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 28.79 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 7.65 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 2 |
| Maximum Number of Lanes: | 2 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Undivided |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Rural |
| Traffic Volume: | |
| Average Traffic Volume: | 9539 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: | 2002 to 2012 |
| Municipality: | |
| State: | FL |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 129 crashes before, 113 crashes after |
| Sample Size (sites): | 43 sites before, 43 sites after |
| Sample Size (miles): | 32.808 miles before, 32.808 miles after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 01, 2015 |
| Comments: | |
