Study Details
Study Title: Development of Crash Modification Factors for Intersections in Toowoomba city
Authors: Al-Marafi et al.
Publication Date:MAR, 2020
Abstract: employed to recommend multiple treatments for application to improve safety level at hazardous intersections in regional areas. Data from 106 intersections in the regional city of Toowoomba, Queensland, Australia were used in modelling and subsequent analysis. Specifically, crash prediction models were developed to estimate crash modification factors that could be used to propose remedial measures. A total of sixteen geometric and operational conditions were used as explanatory variables including the number of legs at an intersection, the availability of entering and exiting via through lanes, the presence of left-turning lanes, right turning lanes, slip lanes, median islands, traffic control, and speed limits on the feed roads. The Empirical Bayes approach was employed to identify five hazardous intersections in Toowoomba for further investigation. The four most suitable techniques for estimating combined crash modification factors were reviewed and then used to propose effective road safety measures for the five selected hazardous intersections. Finally, this research suggests four future areas worthy of further investigation.
Study Citation: Al-Marafi, M.N., K. Somasundaraswaran, and F. Bullen. "Development of crash modification factors for intersections in Toowoomba city". International Journal of Urban Sciences, Vol. 25(1), (2010) pp. 104-123.
Study Report: Download the Study Report Document
CMFs Associated With This Study
Category: Access management
Countermeasure: Install raised median
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.72 | 28 |  | All | K,A,B,C | All | All |
| 0.58 | 42 | | All | K,A,B,C | All | All |
Category:Intersection geometry
Countermeasure: Change number of through lanes on minor road (from 2 to 1)
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.88 | 12 | | All | K,A,B,C | All | All |
Countermeasure: Install left-turn lane
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.96 | 4 |  | All | K,A,B,C | All | All |
| 0.92 | 8 | | All | K,A,B,C | All | All |
Countermeasure: Install Slip Lane
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.97 | 3 | | All | K,A,B,C | All | All |
| 0.94 | 6 | | All | K,A,B,C | All | All |
Category:Intersection traffic control
Countermeasure: Install a traffic signal
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.87 | 13 | | All | K,A,B,C | All | All |
Category:Speed management
Countermeasure: Lower posted speed from 60 km/h to 50 km/h
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.68 | 32 | | All | K,A,B,C | All | All |
