VE-I-5: Impacts on roads due to weather conditions and weather patterns
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2023 Monitoring Report on the German Strategy for Adaptation to Climate Change
Click to enlargeSource: Chris / stock.adobe.com
VE-I-5: Impacts on roads due to weather conditions and weather patterns
Highway maintenance services were extraordinarily busy in 2007, 2010, 2018 and 2021. In 2007 and 2010 the main task was to remedy the damage wrought by hurricanes Cyril and Xynthia respectively. In 2018 the impacts of storm, hailstones and heavy rain kept the highway maintenance services in Hesse, Rhineland-Palatinate and North Rhine-Westphalia exceptionally busy. In 2021, the ‘Bernd‘ low-pressure system was responsible for the high expenditures on working time.
The illustration VE-I-5 ’Impacts on roads due to weather conditions and weather patterns’ shows a bar chart for the years 2007 to 2021 for the time expended on work due to extreme weather and disasters in hours per 1,000 kilometres of the network length (for 2021, not including motorways). This involves a differentiation between Länder who document the time expended on work according to items 6.03 and 4.06 (later 6.1.3) of the specification for highway maintenance services on federal trunk roads on one hand, and on the other hand those who have only reported the time expended on work under item 6.03. The first-named time series does not indicate a trend whereas the second time series pertaining to item 6.03 shows a trend with trend reversal from falling to rising. NB not all Länder were able to supply data for all years concerned. The time expended on work was particularly high in 2007 totalling in excess of 5,500 hours per 1,000 km network length. However, it was not possible to take more than the Länder Brandenburg and Rhineland Palatinate into account.
Clean-up operations after storm and heavy rain
In recent years road transport infrastructures in various parts of Germany were affected repeatedly by tempests and their aftermath: Rivers broke their banks flooding transport routes including federal trunk roads and motorways. Heavy rainfalls triggered flash floods which effectively washed cars away and undermined roads, damaging infrastructures such as rainwater retention basins (cf. Indicator VE-I-3); mudslides, toppled trees and windthrows; on some occasions accumulations of hailstones blocked roads and left a lot of dirt and damage behind on roadsides, so that roads had to be closed to traffic.
The total extent of damage to roads and infrastructure often does not reveal itself until a tempest has passed or the high-water level has receded. The task to remedy such damage falls into the remit of highway maintenance administrations at Länder level, whereas responsibility for motorways has been, since its inception in 2021, the remit of the Autobahn GmbH des Bundes (AdB) at federal government level. Major restoration work on buildings or embankments is usually entrusted to private companies. Minor repairs and cleansing jobs are carried out by highway maintenance services. Highway maintenance work is carried out by employees of motorway and road maintenance depots. They make sure that the road network is safe and functioning. All measures required to ensure adequate control, servicing and maintenance of Germany’s roads are implemented under the premise that the smooth flow of traffic is affected as little as possible.
The new version of a specification detailing the requirements for work to be carried out by highway maintenance services on federal trunk roads is contained in the ‘Leistungsheft für den Straßenbetriebsdienst auf Bundesfernstraßen, edition 2021’170 published in the beginning of 2022. According to the amended item 6.1.3 ‘Measures to be taken for extraordinary weather events and disasters’, the removal or repair of any road damage immediately after tempests is the remit of highway maintenance services. Highway maintenance services are also required to remove any obstacles from roads, such as tree branches or limbs, and to remove any detritus or pollution, to restore any damaged road signs or markings, to restore road banks and to clear ditches. Where specific road sections are impassable, highway maintenance services will handle traffic control using appropriate signage and barriers or cordons.
Subject to the availability of data for the individual Länder, the indicator shows the expenditure for services rendered in connection with extraordinary weather events under the remit of various Länder. In this context it must be borne in mind that in connection with such events in some Länder, only the services rendered for ‚traffic control measures in specific weather events’ (item 6.03) were covered, as per the specification dating back to 2004 (item 6.03). In other Länder the necessary measures – in relation to extraordinary weather events – for the removal of detritus from road surfaces obstructing and endangering traffic – were covered in addition (item 6.03, plus selected expenditures as per item 4.06). The latter formulation is a forerunner for the capture of expenditure under item 6.3.1 of the new specification. Given the differences in the scope of services rendered, the diagram illustrates the two approaches separately. In order to make the expenditure incurred in various Länder comparable, the values were in each case calculated in relation to the length of the road network under the remit of each highway department.
The time expended on dealing with extraordinary weather events and disasters was particularly high in the years 2007 and 2010, and latterly also in 2018 and 2021. In the first-mentioned decades, a large area of Germany was struck by hurricanes Cyril and Xynthia respectively. In woodlands and forested areas, a great number of trees were uprooted and branches were ripped off. This resulted in obstructions and damage to roads which had to be remedied by highway maintenance services. The labour involved caused a distinct amount of additional time expenditure. In May 2018, a considerable number of violent tempests occurred in many German Länder. Particularly hard-hit were the Länder Hesse, Rhineland-Palatinate and North Rhine-Westphalia, where the highway maintenance services incurred high expenditures in the course of remedying the impacts of flooding, mudslides, hailstorms and heavy rain. By contrast, the time expenditure on work carried out in 2021 seems to be only a partial reflection of the impacts caused by the low pressure system known as Bernd. The reason for this is the disastrous extent of floodwater and inundation events. Now as before, in order to remedy damage, measures are taken which fall outside the gamut of services rendered by highway maintenance services, as this work is undertaken by private enterprises and therefore not reflected in the time series.
Once the upgraded specification is established and applied by all Länder as well as by the AdB (Autobahn GmbH des Bundes), it will in future be possible to make comparable statements on time expenditure incurred by highway maintenance services in the aftermath of extraordinary weather events and disasters. To that end, the Federal-Länder Working Party BEKORS (Calculation of operating costs incurred by highway maintenance services / Betriebskostenrechnung im Straßenbetriebsdienst) has revised and enhanced the relevant specification to incorporate the collation of data on time expenditure in a homogeneous and comparable manner. For this purpose, the services to be rendered were described in detail, including a clarification stating that the time expended under item 6.1.3 ‘Measures to be taken in cases of extraordinary weather events or disasters’ is to be allocated not only to initial measures but also to follow-up measures.
On this basis, the scope of this indicator can in future be expanded to cover all Länder of the Federal Republic of Germany. This will make it possible to assess whether the labour expended on highway maintenance is increasing because nationwide, Germany is experiencing a greater amount of road damage and obstructions as a result of extreme weather events – a consequence of the expected climate change impacts on the transport sector.
170 - BMVI – Bundesministerium für Verkehr und digitale Infrastruktur (Hg.) 2021: Leistungsheft für den Straßenbetrieb auf Bundesfernstraßen. Ausgabe 2021. Ersetzt im Mai 2023: BMDV – Bundesministerium für Digitales und Verkehr (Hg.) 2023: Leistungsheft für den Straßenbetrieb auf Bundesfernstraßen. Ausgabe 2023. 99 pp. https://www.bast.de/DE/Verkehrstechnik/Fachthemen/Daten/Leistungsheft-Strassenbetrieb.html
