By Berend Booms, Associate Editor | Future of Assets
On September 7, Rijkswaterstaat, the Dutch government agency responsible for the country’s main roads, waterways and flood defenses, closed the Hardenbergerbrug on the A28 motorway in both directions, after more sand and gravel had washed away from around its piers than expected. The next morning, the main detour held 23 kilometers of traffic, and the transport association TLN estimated that every day of closure was costing the sector around €1 million. The bridge reopened two and a half days later.
This story caught my eye because the repair had already been planned for November. The scour around the piers was a known problem, but the damage progressed faster than the calendar allowed for. It’s not an isolated incident either; living in the Netherlands, I come across many stories like this, and it’s high on the national agenda. In his annual speech from the throne last year, King Willem-Alexander spoke of ‘the largest maintenance task ever’ facing Dutch roads, bridges and other infrastructure. Nowhere does that task become more apparent than at the Van Brienenoordbrug in Rotterdam.
A Warning Twenty Years in the Making
The Van Brienenoordbrug is the busiest bridge in the Netherlands, with around 250,000 vehicle crossings a day. It has also made headline news: in 2024, the mayors of Rotterdam and The Hague called the renovation imperative, warning that lanes might otherwise have to close to prevent collapse risk, a claim that was rebutted within days by Rijkswaterstaat. According to the agency, there is no risk of collapse, but the movable section with its drives and control systems has reached the end of its life, and the chance of breakdowns and unplanned maintenance is rising. Until the renewal, the agency is replacing parts more often as a precaution. If you have ever kept a plant running on aging machinery and a legacy control system, this will sound familiar to you, and you’ll know how long that strategy tends to last.
Rijkswaterstaat reportedly flagged the bridge's poor condition as early as 2008. In 2018, then-minister van Nieuwenhuizen called the renewal of the country’s bridges and tunnels ‘the largest task ever in the Netherlands’, with the Van Brienenoordbrug the most prominent structure named. In 2022, the renovation was estimated at €680 million, but the only bidding consortium walked away, so the tender was stopped in early 2024. Just over one year later, in May 2025, the estimate had risen to between €1.5 and 2 billion: in roughly three years, the projected price had tripled. Some of this can be explained by inflation and a challenging market, but what it mostly shows is that deferred work keeps getting more expensive while the decision is kept waiting. Simply put, this is a prime example of why early maintenance matters: maintain early and you stop cracks from growing, wait too long and you will end up replacing whole components. The longer you wait, the more expensive it gets.
The current plan for renovation reflects that history. Rijkswaterstaat has split the renovation into four contracts, with the first being awarded in June of this year on a target-price basis where overruns and savings are shared with the contractor. This part is interesting, because to me it signals that Rijkswaterstaat understands the market is not going to price every unknown in a ~60-year-old bascule cellar on fixed terms. The bascules are the first phase, coming in 2029, followed by new arches in 2030 and 2032, with completion planned for 2033.
Twenty Weeks at Half Capacity
What’s looking to be the most disruptive phase of the renovation is going to take place over the summer of 2029. For a duration of roughly twenty weeks only half the lanes will be available. Regional authorities have calculated that at least 85,000 vehicles a day will need to find another route or stay off the road completely. Efforts to manage this are well underway: residents have been urged to work from home where possible, and employers to make that possible, and it has been suggested that the main hospitals and some schools shift their hours temporarily to allow a more even split of traffic. That is a lot to ask. Even the most successful closures in the Netherlands have taken just 30 to 40 percent of traffic off the road, on motorways carrying a fraction of what crosses the Van Brienenoordbrug every day.
The surrounding network offers little relief because it is also aging: the Merwedebrug has been closed to trucks since July, after its steel turned out to be weaker than assumed; the Suurhoffbrug had to close earlier this year because its safety could not be guaranteed; and the Papendrechtsebrug is closed to road traffic until April 2027 while its own bascule is renewed. Vehicles are not the only concern, either: more than 120,000 vessels pass under the Van Brienenoordbrug each year, while it opens only about 150 times. 2029 is still a couple of years out, and until then, aging drives still have to work every time; a failure could leave the bridge unable to open, blocking shipping for an unknown period.
Two Ways Out of Service
An aging asset can leave service in two ways: in the case of the Van Brienenoordbrug, it’s planned years in advance on the owner’s terms, while for the Hardenbergerbrug, it came at no notice on the asset’s terms. The first draws more attention because it plays out over years; the second is the one that catches asset owners off guard. With a national funding gap of around €80 billion through 2040, the government's new principle of "life extension where possible, renewal where necessary" only works if we know which assets are which.
Recent reporting by the Dutch investigative journalism platform Follow the Money (FTM) points to a harder case still. FTM found that at least sixteen Dutch bridges contain prestressing steel vulnerable to hydrogen embrittlement, which can bring a structure down without warning: exactly what happened to the Carola Bridge in Dresden in 2024. Following this collapse, Rijkswaterstaat’s advisers recommended twice-yearly inspections, steel sampling, recalculation and strengthening or monitoring, as required. According to FTM, there is no bridge that has had every measure carried out, with about half going uninspected in the past six months.
The Hand Can’t Fix What the Eye Can’t See
Hydrogen embrittlement is a well-known failure mode: the government's own prioritization framework names it as a specific risk. Looking back at what happened in Dresden, investigators concluded the damage had most likely been present since construction and had gone undetected by regular inspections. That’s the gap we’re staring at: knowing about a failure mode and being able to see it coming.
A risk that gives no warning cannot be managed by calendar or by eye alone. The repair of the Hardenbergerbrug was already on the schedule for months, but time rarely works in favor of an aging asset. We can plan the work as carefully as we like; the asset follows its own schedule, and it does not wait for ours. The Netherlands has given its backlog a name, calling it “the largest maintenance task ever,” and the work will run well into the next decade. The budget sets the limits of what we can fix. What we can see decides whether we fix the right things in time.