Traffic Conflict–Based Before–After Study with Use of Comparison Groups and the Empirical Bayes Method

Reyad, Passant; Sacchi, Emanuele; Ibrahim, Shewkar; Sayed, Tarek

doi:10.3141/2659-02

Cited by 15 publications

(9 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of these, only the comparison group method uses comparison sites in this evaluation. Researchers have used the comparison group method to evaluate different safety countermeasures for many years (36,37). This method has also been previously used to conduct before-after analyses on LED and RFB WWD countermeasures (1)(2)(3)(4)(5).…”

Section: Methods 2: Wwcr Reduction Using Reduction In Wwd Eventsmentioning

confidence: 99%

Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida

Sandt

Al-Deek

Kayes

et al. 2019

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

In recent years, rectangular flashing beacons (RFBs) and other technologies have been used as wrong-way driving (WWD) countermeasures on limited access facilities. Studies have shown that these devices effectively reduce WWD, but no research has compared the financial benefits and costs of these countermeasures. Three different methodologies were used to conduct benefit–cost analyses for RFB WWD countermeasures installed on Central Florida toll road exit ramps. The studied benefits included savings from reductions in WWD crashes, non-crash events, and injuries, whereas costs included equipment, installation, and maintenance costs. For the first two methodologies, the reduction in WWD crash risk (WWCR) at the RFB-equipped ramps was determined. This WWCR considered non-crash WWD events, interchange design, and traffic volumes. Different measures of effectiveness (turn-around percentage of detected wrong-way vehicles at the RFB ramps and reduction in WWD 911 calls and citations at the RFB interchanges compared with similar comparison interchanges without RFBs) were used in these two methodologies to estimate the WWCR reduction and associated savings. For the third methodology, the relationship between WWD crashes and non-crash events was used to determine the average savings for WWD 911 calls and citations. Before–after analyses were then conducted to determine the individual reductions in WWD 911 calls and citations. Applying these three methods resulted in life-cycle benefit–cost ratios ranging from 2.49 to 4.10 (crash savings) and from 4.77 to 7.20 (injury savings). Other agencies could use these methodologies to determine the benefits of WWD countermeasures or other technologies with limited crash data.

show abstract

Section: Methods 2: Wwcr Reduction Using Reduction In Wwd Eventsmentioning

confidence: 99%

Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida

Sandt

Al-Deek

Kayes

et al. 2019

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

show abstract

“…To statistically analyze the efect, we adopted the odds ratio (OR) method [27,[40][41][42]. Tis method is usually employed to systematically compare the efects on experimental sites and control sites.…”

Section: Before-and-after Studymentioning

confidence: 99%

A Before-and-After Study of a Collision Risk Detecting and Warning System on Local Roads

Yun

Selmoune

Chae³

et al. 2023

Journal of Advanced Transportation

View full text Add to dashboard Cite

Local roads have numerous blind spots caused by complex geometry, obstacles, and narrow width. Thus, conventional proactive countermeasures, such as passive traffic signs and convex mirrors, have not always been effective in preventing local road collisions. In this paper, we present a novel proactive two-step approach for traffic safety on local roads, comprised of detection of pedestrian-to-vehicle and vehicle-to-vehicle collision risks and warning systems. First, using video surveillance and radars to eliminate blind spots, the system detects road objects, predicts their trajectories and reachable areas, and identifies a potential risk situation. Second, it provides road users such as vehicles and pedestrians with warnings through LED variable message signs, which allows them to react effectively in risky situations. We have applied the system to two local road sites in South Korea, including a university campus in Seoul City and an apartment complex in Daejeon City. The detecting system has been validated using a confusion matrix. We have assessed the warning effect through a before-and-after study and found that the proposed system contributed to the improvement of traffic safety at the case study site in that traffic conflicts decreased by 55–62%.

show abstract

“…There are many established methods for network screening, such as the empirical Bayes method and the use of safety performance functions (SPF), but they become cumbersome to implement over a large spatial scale. These methods also suffer from site selection and categorization biases that can potentially influence the estimates [8]. As such, there has been a growing interest into Geostatistics as a possible replacement for these methods, especially for applications over a large spatial area.…”

Section: Introductionmentioning

confidence: 99%

Advances in Regression Kriging-Based Methods for Estimating Statewide Winter Weather Collisions: An Empirical Investigation

Wong

Kwon

2021

Future Transportation

View full text Add to dashboard Cite

Winter conditions create hazardous roads that municipalities work hard to maintain to ensure the safety of the travelling public. Targeting their efforts with effective network screening will help transportation managers address these problems. In our recent efforts, regression kriging was found to be a viable and effective network screening methodology. However, the study was constrained by its limited spatial extent making the reported results less conclusive and transferrable. In addition, our previous work implemented what has long been adopted in most of conventional studies—the Euclidean distance; however, use of the road network distance would, intuitively, result in further improving kriging estimates, especially when dealing with transportation problems. Therefore, this study improves upon our previous efforts by developing a more advanced kriging model; namely, network regression kriging using the entire state of Iowa with the significantly expanded road network. The transferability of the developed models is also explored to investigate its generalization potential. The findings based on various statistical measures suggest that the enhanced kriging model vastly improved the estimation performance at the cost of greater computational complexity and run times. The study also suggests that regional semivariograms better represent the true nature of the local variances, though an overall model may still function adequately if higher fidelity is not required.

show abstract

Traffic Conflict–Based Before–After Study with Use of Comparison Groups and the Empirical Bayes Method

Cited by 15 publications

References 12 publications

Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida

Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida

A Before-and-After Study of a Collision Risk Detecting and Warning System on Local Roads

Advances in Regression Kriging-Based Methods for Estimating Statewide Winter Weather Collisions: An Empirical Investigation

Contact Info

Product

Resources

About