Amsterdam’s historic canals and bridges were never built for today’s 30‑ton trucks, yet they carry them every day. To keep quay walls and bridges safe without shutting the city down, Amsterdam needs reliable data on what really drives over its infrastructure – not just assumptions.
Together with the Municipality of Amsterdam and Technobis, PhotonFirst has installed a fiber‑optic Weigh‑in‑Motion (WIM) system in the asphalt at ‘Droogbak’, next to Central Station. It measures the actual weight of every vehicle in real time – invisible to drivers, but invaluable for the city.
Traditional camera systems classify vehicles and estimate weight based on type. But they cannot tell whether a truck is empty or fully loaded, which makes it hard to judge the real impact on vulnerable structures.
By measuring tiny deformations in the road surface with fiber optic sensors, the Droogbak WIM system delivers:
This turns “educated guesses” into hard evidence for engineers and policymakers.
In three narrow grooves in the asphalt, sensor beams with Fiber Bragg Gratings (FBGs) detect strains as wheels pass by. PhotonFirst interrogators convert changes in reflected light into accurate strain signals and then into weight information, all processed in a small roadside cabinet.
Fiber optic sensing offers key advantages in an urban environment:
For Amsterdam, Droogbak is a step toward data‑driven management of bridges and quay walls. Continuous weight data enables:
PhotonFirst brings years of experience in fiber optic sensing and photonic systems for mission‑critical applications to this project. We provide the sensors, interrogators, data acquisition and signal processing, and work closely with the Municipality of Amsterdam, Technobis and other partners on design and installation.
“Thirty tons of diesel on three thin fibers” nicely captures what this pilot proves: invisible photonics can make a very visible difference in keeping historic cities safe, accessible and future‑proof.