Summary
Dutch traffic lights use advanced detection technologies that adjust signals dynamically based on real-time conditions. The systems known as VRI (Verkeersregelinstallatie, traffic control installation) and iVRI (intelligente Verkeersregelinstallatie, intelligent traffic control installation) form the backbone of the Netherlands’ adaptive traffic management network. Within this framework, the operating mode wachtstand groen (“green waiting state”) keeps a light green until perpendicular traffic appears, optimizing safety and efficiency. The city of Spijkenisse, within the Nissewaard municipality, has implemented this technology through sensor-equipped and upgraded intelligent systems.
Context and Scope
This article encompasses verified information on Dutch traffic light operations and adaptive signal control technologies as of October 2025 (Europe/Amsterdam). It integrates details about the logic of wachtstand groen, the distinctions between VRI and iVRI systems, and specific applications in Spijkenisse. The evidence combines governmental documentation, municipal reports, and verified Dutch technical sources confirming the existence and functioning of these systems across the country.
Factual Narrative
Verified Sensor-Based Operation
Most Dutch intersections are equipped with inductive loops called detectielussen, embedded in the pavement to detect vehicles through changes in magnetic fields. When a vehicle approaches, the loop signals the control system that a green light is needed. If no presence is detected, the controller holds or skips the phase. According to Rijkswaterstaat (the Dutch National Road Authority), nearly all intersections operate through this detection-based logic.
Intelligent Traffic Management Systems
Modern Dutch traffic lights are transitioning from traditional VRI systems to iVRI, or intelligent installations capable of communication between intersections and with vehicles. These systems collect real-time data on traffic flow, public transport, and cyclists, enabling the network to respond dynamically to actual conditions. The Ministry of Infrastructure and Water Management oversees the nationwide deployment of these intelligent systems, which enhance efficiency and safety.
Difference Between VRI and iVRI
A VRI is a conventional traffic control installation that uses preprogrammed cycles and basic vehicle detection. It can adjust timings locally based on sensor input but operates independently.
An iVRI, by contrast, is a connected and adaptive version of a VRI. It communicates with other intersections, vehicles, and regional traffic management centers via intelligent transport systems (ITS). This connectivity allows iVRI to give priority to buses, emergency vehicles, or cyclists and to synchronize multiple intersections, reducing waiting times and emissions.
In short, an iVRI is a smart, networked evolution of the traditional VRI, capable of understanding its traffic environment and acting accordingly.
“Wachtstand Groen” — The Green Waiting State
The operational mode wachtstand groen is formally recognized in Dutch traffic management. It keeps a traffic light green by default and changes it to red only when conflicting traffic is detected. Municipal policies, such as those in Groningen, define it explicitly as “the main direction stays green in the absence of conflict.” The technical platform Wegenwiki explains the mechanism: when a conflict is detected, the system withdraws green and switches to red. This logic applies to both motor vehicles and bicycles, supported by guidelines from the CROW institute (national infrastructure and mobility authority).
Spijkenisse Implementation
Spijkenisse, in the municipality of Nissewaard, employs traffic controllers based on detection loops and is actively upgrading to iVRI systems. Public works reports confirm installation and replacement of detection loops in intersections like Baljuwlaan and Schenkelweg–Veerweg. The MRDH (Metropolitan Region Rotterdam–The Hague) funds these conversions, ensuring the city’s full integration with national smart traffic systems. Local authorities have also emphasized that vehicles must stop near the line to trigger the detectors, confirming the system’s active sensing mechanism.
Protected Phases and Perpendicular Traffic
Dutch intersections separate potentially conflicting directions using protected phases. Under wachtstand groen, a turn arrow or lane remains green by default until traffic appears on a perpendicular route. When conflicting movement is detected, the system safely transitions the arrow to red. This configuration ensures maximum flow efficiency without compromising safety, aligning perfectly with observed behavior at intersections in Spijkenisse.
Entities & Roles Index
- Rijkswaterstaat: National Road Authority confirming the use of inductive detection loops.
- CROW: National infrastructure institute defining standards for traffic signal control.
- Wegenwiki: Technical platform describing wachtstand groen operation.
- Groningen Municipality: Issuer of formal definition for wachtstand groen.
- Nissewaard Municipality / Spijkenisse: Local government applying VRI and iVRI systems.
- MRDH (Metropolitan Region Rotterdam–The Hague): Regional funding body supporting iVRI deployment.
- Ministry of Infrastructure and Water Management: Oversees national rollout of intelligent traffic installations.
Practical Conclusions
Dutch intersections operate under a highly developed system of detection and adaptive control. The principle of wachtstand groen—keeping a light green until perpendicular traffic appears—is an established and documented logic, not a coincidence. The difference between VRI and iVRI lies in the latter’s intelligence and connectivity, allowing the system to coordinate with other signals and vehicles. Spijkenisse’s ongoing modernization through MRDH-funded projects ensures that such logic is active locally. The system exemplifies the Netherlands’ leadership in efficient, safe, and adaptive traffic management.
Sources
- https://www.rijkswaterstaat.nl/wegen/verkeerslichten-en-verkeersborden/verkeerslichten — National explanation of detection loop operation.
- https://www.crow.nl/publicaties/verkeersregelinstallaties — Technical standard for traffic light control and adaptive signal logic.
- https://wegenwiki.nl/Wachtstand — Technical definition and explanation of wachtstand groen.
- https://gemeente.groningen.nl — Municipal policy defining the “green waiting state.”
- https://mrdh.nl — MRDH overview of iVRI modernization projects in Nissewaard.
- https://www.grootnissewaard.nl/nieuws/algemeen/201066/kruispunt-schenkelweg-veerweg-gaat-op-de-schop — Local report confirming VRI upgrades with detection loops.
- https://algoritmes.overheid.nl/en/algoritme/46452825 — Official government registry describing iVRI operation and algorithms.
Appendix
Wachtstand Groen
“Green waiting state.” Default-green mode that switches to red when conflicting traffic is detected.
Detectielus
Inductive detection loop in the pavement for vehicle presence sensing.
VRI
Verkeersregelinstallatie — traditional traffic control installation using preset logic.
iVRI
Intelligente Verkeersregelinstallatie — intelligent, connected signal system adapting in real time.
MRDH
Metropolitan Region Rotterdam–The Hague, regional transport body funding iVRI upgrades.
Nissewaard / Spijkenisse
Municipality and city implementing modern adaptive traffic control with detection-based systems.
My Diary - Leonardo Cardillo 