Applying Roadscor for safe road design in Noord-Brabant (NL)
The Challenge
The Province Noord-Brabant (The Netherlands) is the road authority responsible for provincial roads' (N-roads) design, maintenance, and safety. In 2024 the Province launched the Zero Vision plan (Brabants Verkeersveiligheidsplan - BVVP) aiming to halve the number of traffic victims by 2030 compared to 2019. The plan emphasises improvements in infrastructure, behaviour and enforcement, with special attention to cyclists, distracted drivers and inexperienced road users. As part of the Zero Vision, the N286 was identified as a road in need of improved safety.
The intersection was known for red light violations, leading to increased safety risks and the concerns of the Province on the likelihood of dangerous interactions between road users, particularly at peak times or during complex traffic flows.
The intersection was selected to be assessed as part of a program by SWOV Institute for Road Safety Research, which conducted camera observations to determine road user behaviour and risk identification. The Province saw the opportunity to compare this approach against the conflict analysis, challenging Roadscor to perform the assessment with minimal data input. Roadscor worked solely based on the vLOG traffic light data collected by sensors embedded in the road surface, which continuously log vehicle detections, signal changes, and priority requests at intersections.
The Solution
The Province Noord-Brabant trusted Roadscor to perform safety analysis and to suggest design measures to improve the road safety in the intersection.
Roadscor assesses safety based on the probability and severity of conflicts of the routes of road users. This approach is enabled by software originally developed by Roadscor’s partner Siemens for the safe introduction of autonomous vehicles according to ISO21448 (SOTIF), where it is used to detect unknown-unsafe scenarios.
Although the vLOG data provided insight into the routes, intensities and behaviour (speed and red light violations) or motorised traffic and cyclists, data on pedestrian behaviour was lacking as there was no dedicated pedestrian crossing at the intersection. The vLOG data also cannot provide input on cyclists driving against traffic. For this reason, the vLOG data was complemented with synthetic data for these routes.
In total Roadscor considered over 4,000 different traffic paths of the different road users, including varying lateral deviations and speed profiles, over more than 700 routes through the intersection. These were simulated against each other in time to determine the probability and the controllability (the degree to which the incident could potentially be avoided by a road user) of the conflicts.
Making an impact
Roadscor simulated 4,033 traffic paths. The analysis revealed conflicts (collisions and near-misses) for 50 unique routes and 125 critical conflicts: 65 involving pedestrians, 8 involving cyclists, and 52 involving vehicle-to-vehicle.
Even without historical (crash) data or behaviour observation, Roadscor delivered actionable insights to improve traffic safety - before incidents occur - supporting the region’s Vision Zero ambitions.
Roadscor’s work for Province Noord-Brabant will be completed with a second iteration at the same intersection, with the advised measures and modifications by the traffic engineers of Haskoning included. Where the current results already provide a robust foundation for evidence-based decision-making, a dedicated crossing for pedestrians as well as adjusted green and clearance times are expected to result in less probable, more controllable and less severe conflicts – and thus an improved road score.
Lessons learnt
A significant enhancement in this upcoming phase is the integration of accident severity analysis, which will include severity-weighted risk indicators in the simulation outcomes. The severity is determined based on the simulation runs in combination with data from Roadscor’s partner VUFO and the German In-Depth Accident Study database.
This addition will quantify the likelihood of conflicts and assess their potential consequences, enabling more targeted and cost-effective interventions. Alongside the probability and controllability, the indicators allow risk and safety of the intersection to be quantified, providing road authorities with a Safety Performance Indicator directly related to the prevention and mitigation of conflicts, as well as the costs associated.
