Modernising dilapidated motorway bridges is a priority
Many motorway bridges are in a poor condition. The Federal Ministry for Digital and Transport wants to remedy this situation by launching the bridge modernisation programme. We have examined the implementation of the programme and submitted our findings in an advisory report to the Budget Committee of the German Parliament. In short: the Ministry will miss its goal of modernising all dilapidated bridges in particularly important parts of the motorway network by 2032 at the latest - further decay and bridge closures are inevitable.
At a bridge summit in March 2022, the Ministry presented its future package as to efficient motorway bridges as well as its assessment of the condition of federal trunk road bridges (bridge balance). The result: the modernisation of bridges is to be strategically realigned. The aim is to significantly speed up the process. The Ministry intends to achieve this aim in particular by launching the bridge modernisation programme.
Goals of the bridge modernisation programme
For its programme, the Ministry selected the worst structures on the basis of certain criteria. These are bridges or bridge substructures that generally need to be reinforced, i.e. their load-bearing capacity increased, or replaced by new structures.
For especially important parts - around half the length - of the entire motorway network, the Ministry has set the modernisation of almost 4,000 substructures as a priority by 2030 at the latest. In the meantime, it has extended the programme to around 4,500, adding particularly urgent individual structures outside the sub-network and postponed the target year to 2032.
In order to achieve its goal, the Ministry plans to increase the number of annual completions from 122 substructures in 2021 to 400 in 2026 and to maintain this higher number.
Our findings show that the Ministry underestimates the need for modernisation: In early 2023, more than 5,000 substructures needed to be modernised, and completion by the target year is not achievable even with 400 substructures as from 2026.
Bridge refurbishment backlog
The Autobahn GmbH is the body responsible for motorways and therefore also for bridges. It has to implement the Government's programme. In its own bridge modernisation strategy, it defined a 40% smaller sub-network (priority network) compared to the Government's programme due to limited staff capacities, and with 2035 a later target year.
The following figure shows that the Autobahn GmbH will not reach the milestones set by the Government's programme. The gap between "target" and "actual” situation widens rapidly.
In this respect, we consider the Ministry's goal of completing the modernisation by 2032 to be unrealistic. Due to staff shortages, the Autobahn GmbH will have difficulties even in achieving its own goal, which deviates from the programme, i.e. modernising the smaller number of substructures of the smaller priority network by 2035.
In this context, we are critical of the fact that the Autobahn GmbH is working on a large number of less urgent new construction and expansion projects that are not included in the Ministry’s programme.
Bridge modernisation remains a challenge - target achievement
The modernisation of bridges is currently the most urgent task of the Autobahn GmbH as to road infrastructure. Against the backdrop of staff shortages, the only remaining option for the time being is to focus on substructures that are relevant to the programme and are therefore priorities. Less urgent bridge projects should be postponed.
Due to the gradually expiring service life of the 27,915 substructures in the entire motorway network, their maintenance will also be a permanent challenge for the Autobahn GmbH - with almost 400 substructures to be modernised every year. It must be given the staff and financial resources to cope with this task. The legislator could support this by redistributing budget funds in favour of maintenance tasks and earmarking funds for bridge modernisation efforts.
The Ministry agreed with our recommendation that the Autobahn GmbH should be strengthened in terms of staff. It wants to give even greater consideration to bridge modernisation in the new financing and implementation plan of the Autobahn GmbH, without neglecting other important tasks.
It remains to be seen when all dilapidated bridges within the entire motorway network will be refurbished and the risk of closures be averted.
You can find more information about our findings and recommendations in our advisory report to the parliamentary Budget Committee. Please note: The report is only available in German.