# A Novel Methodology for Planning Urban Road Safety Interventions
## 4 Validation of the Proposed Methodology via Case Study Application
### Proactive Analysis of Black Spots and Intervention Proposals
#### 4.3.1 Black Spots for Pedestrians
Traffic volume data from the municipality indicates an average daily traffic (ADT) of 12,500 vehicles westbound (toward the city center) and 7900 vehicles eastbound (leaving the city). Figure 8: Star rating Option 1: (**a**) east direction and (**b**) west direction. Figure 9: Star rating Option 2: (**a**) east direction and (**b**) west direction. Between 2017 and 2023, 10 pedestrian-related accidents occurred at this location, including one fatality. Based on accident geolocation, the crossings were analyzed separately as critical point B1 with pedestrian crossing and B2 with pedestrian crossing adjacent to bus stops in both directions (see Figure 10b). Both crossings share identical geometric and traffic flow characteristics, with a road width of approximately 9 m, two 4 m-wide lanes, and 0.5 m shoulders. However, B2 is treated separately due to the influence of nearby bus stops. This stretch of road is classified as E2 (secondary neighborhood street), where the wide lanes encourage speeding, posing significant risks to vulnerable road users. Given their similarities, a single proactive simulation was conducted using the iRAP star rating model for the current state (Option 0) at both crossings. With an operational speed of 50 km/h for both directions, the results revealed a higher pedestrian risk score for westbound traffic, nearly double that of the eastbound direction, reflecting the differing traffic volumes (see Figure 11). To reduce operational speeds along the identified stretch, two traffic calming measures were proposed. The first intervention option proposes a pedestrian crossing with a hook-shaped refuge island at point B1 (see Figure 12a) and a central anti-overtaking refuge island near the bus stop at point B2 (see Figure 12b). This solution involves the addition of pedestrian refuge islands to narrow lane widths, thereby reducing drivers' visual space and encouraging lower speeds. In detail, at point B1, a 2 m-wide hook-shaped pedestrian island would enhance safety and also support bicycle crossings by optimizing available space. At point B2, near the bus stop, a central refuge island would function as both a pedestrian safety feature and an anti-overtaking barrier. Figure 11: Star rating option 0: (**a**) east direction and (**b**) west direction. Figure 10: Concentration map outputted by GIS for: (**a**) accidents involving at least one pedestrian, critical point B and (**b**) Pedestrian accidents, subdivided points B1 and B2. These interventions aim to induce slight deviations in vehicle trajectories, effectively calming traffic. The measures include adequate visibility and signage enhancements for day and night conditions. Proactive risk analysis for this option, assuming a reduction in operating speed from 50 km/h to 35 km/h, showed significant improvements in safety (see Figure 13). An alternative intervention involves the installation of \"Berlin cushions\" before the pedestrian crossings. This solution is favored over speed bumps as it does not disrupt public transport operations, such as bus routes (see Figure 14). Assuming a reduced crossing speed of 30 km/h, the proactive risk analysis for this speed management solution demonstrated notable safety improvements (see Figure 15). While the risk reduction is less pronounced than that achieved with signalized crossings, the intervention still provides a meaningful enhancement to road safety. Figure 14: Installation of Berlin cushions (in red). Figure 12: Installation of a pedestrian crossing (**a**) with a hook-shaped refuge island (in red) and (**b**) with bus stop (in blue) and central anti-overtaking island (in red). Figure 13: Star rating Option 1: (**a**) east direction and (**b**) west direction. Figure 7:0 Star rating Option 2: (**a**) east direction and (**b**) west direction.