CMF / CRF Details
Implement Active Traffic Management Strategies with Hard Shoulder Running
Countermeasure ID: 10021
Description: Implement a mix of advisory variable speed limits, lane use control signals, and hard shoulder running on a segment of interstate.
Prior Condition: Static speed limits, no lane use control signals, and no hard shoulder running.
Category: Advanced technology and ITS
Study: Evaluation of the Impact of the I-66 Active Traffic Management System: Phase II, Dutta et al., 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 105 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.607 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.113 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 39.3 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 11.3 |
| Applicability | |
|---|---|
| Crash Type: | Rear end |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Principal Arterial Interstate |
| Street Type: | |
| Minimum Number of Lanes: | 6 |
| Maximum Number of Lanes: | 8 |
| 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 133000 to Maximum of 184000 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 158746 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 2016 |
| Municipality: | |
| State: | VA |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 216 crashes before, 33 crashes after |
| Sample Size (sites): | 3 sites before, 3 sites after |
| Sample Size (site-years): | 12 site-years before, 3 site-years after |
| Sample Size (miles): | 7.2 miles before, 7.2 miles after |
| Sample Size (miles): | 28.8 mile-years before, 7.2 mile-years after |
