Unbridged stretches of the Rhine AI-pedia

The unbridged stretches of the Rhine are the sections of the river that no fixed bridge crosses. On these sections, people and vehicles cross by ferry, or travel to the nearest bridge. The best-known and longest such stretch on the navigable Rhine lies in Germany. It runs between Wiesbaden and Mainz in the south and Koblenz in the north. It covers the wine-growing Rheingau and the deep gorge of the Upper Middle Rhine Valley, and is about 80 to 85 kilometres long. In this section, the river is crossed only by ferries.

The Rhine is one of the most heavily bridged rivers in Europe. It flows through or past Switzerland, Liechtenstein, Austria, Germany, France and the Netherlands. Between Basel and the Dutch border, most large towns have at least one road or railway bridge. Gaps of more than a few tens of kilometres are rare. The Mainz–Koblenz gap is therefore unusual. It is caused by a combination of geography, history, heritage protection and local politics.

For several decades there has been a debate about building a road bridge in the gorge, usually called the Mittelrheinbrücke (Middle Rhine Bridge), near St. Goar and St. Goarshausen. Supporters argue that it would end the isolation of communities on each bank, particularly at night. Opponents have raised concerns about the World Heritage landscape, cost and traffic. As of the mid-2020s, the bridge was still in planning and had not been built.

Measuring the Rhine: the Rhine kilometre

Positions on the Rhine are normally given in Rhine kilometres (German: Rhein-Kilometer, abbreviated Rhein-km). This is a standard distance scale that runs downstream. Its zero point is at the old Rhine bridge in Konstanz, where the river leaves Lake Constance. The scale ends near the North Sea in the Netherlands, at roughly kilometre 1,033. Numbered signs on the banks mark each kilometre, mainly for shipping.

Some approximate reference points relevant to this article are:

• Basel: about km 165–170 (start of the main navigable Rhine for large ships)
• Mouth of the Main at Mainz: about km 497
• Mouth of the Nahe at Bingen: about km 529
• Loreley rock: about km 554–555
• Boppard: about km 570
• Mouth of the Moselle at Koblenz (Deutsches Eck): about km 592
• Bonn: about km 650–660
• Cologne: about km 685–690

The length of an unbridged stretch depends on which bridges are used as its end points, and on whether railway bridges are counted as well as road bridges. For this reason, published figures for the Mainz–Koblenz gap vary. They are usually given as "about 80 kilometres" or slightly more.

The Mainz–Koblenz gap

End points

Coming downstream from Mainz, the last fixed crossing before the gap is the Schierstein Bridge (Schiersteiner Brücke). It carries the A643 motorway between Wiesbaden-Schierstein in Hesse and Mainz-Mombach in Rhineland-Palatinate. It lies a few kilometres downstream of the centre of Mainz.

The next fixed crossings are at Koblenz. The southernmost is the Horchheim railway bridge (Horchheimer Eisenbahnbrücke). It is followed closely by the Südbrücke (South Bridge), the southernmost road bridge in Koblenz, and then the Pfaffendorf Bridge (Pfaffendorfer Brücke). Between the Schierstein Bridge and the Koblenz bridges there is no fixed road or railway crossing of the river.

Measured between the Schierstein Bridge and the Koblenz Südbrücke, the gap is roughly 84 kilometres. If the railway bridge at Horchheim is taken as the northern end, the figure is slightly lower. Figures of up to 87 kilometres also circulate. These depend on the exact end points and kilometre values used.

Two different landscapes

The gap is sometimes described simply as "the Middle Rhine Valley". In fact, it covers two quite different stretches of river.

• The Rheingau section (roughly Wiesbaden to Bingen/Rüdesheim). Here the Rhine flows mostly westwards. It is wide, slow and dotted with islands, and the valley is open. The right (northern) bank belongs to Hesse and is known as the Rheingau, a well-known wine region. The left bank, around Ingelheim and Bingen, belongs to Rhineland-Palatinate. This section is not part of the gorge. Building a bridge here would be technically easier. The lack of one is more a matter of history, demand and the closeness of the Mainz/Wiesbaden bridges.
• The Upper Middle Rhine Valley (Bingen/Rüdesheim to Koblenz). At Bingen, the river turns north and enters a narrow gorge cut through the Rhenish Slate Mountains. The Hunsrück lies to the west and the Taunus to the east. This section is about 65 kilometres long. It contains the Loreley rock, many castles, and the towns of Bacharach, Kaub, Oberwesel, St. Goar, St. Goarshausen and Boppard. In 2002, it was inscribed on the UNESCO World Heritage List as the "Upper Middle Rhine Valley" (Oberes Mittelrheintal).

The border between the two states also changes along the gap. Hesse holds the right bank only as far as the area around Lorch, near the mouth of the Wisper stream. Below that point, both banks belong to Rhineland-Palatinate. The right bank is in the Rhein-Lahn district and the left bank in the Rhein-Hunsrück district and, further north, the Mayen-Koblenz district. The proposed Mittelrheinbrücke at St. Goar/St. Goarshausen would therefore lie wholly within Rhineland-Palatinate. It would not cross a state border.

Transport along the banks

Although the river itself is unbridged, the gorge is a major transport corridor along the river:

• The West Rhine Railway (Linke Rheinstrecke) runs on the left bank, and the East Rhine Railway (Rechte Rheinstrecke) runs on the right bank. Both are important main lines, with heavy freight traffic.
• Federal road B9 follows the left bank, and federal road B42 follows the right bank.
• The river carries heavy inland shipping traffic. It is one of the busiest inland waterways in Europe.

Each bank therefore has good north–south links. The problem is crossing from one bank to the other.

How people cross: the Rhine ferries

In the absence of bridges, crossings within the gap depend on ferries. Several car ferries operate, together with some passenger-only services, many of which mainly serve tourists. Car ferries in or near the gap include:

• Ingelheim – Oestrich-Winkel (Rheingau section)
• Bingen – Rüdesheim (at the entrance to the gorge)
• Niederheimbach – Lorch
• Kaub – the opposite (left) bank
• St. Goar – St. Goarshausen
• Boppard – Filsen

Most of these ferries are run by local operators, often family businesses or municipal companies. They operate on fixed or frequent schedules during the day.

Limitations of ferries

Ferries have several limitations compared with a bridge:

• No night service. Ferries generally stop running in the late evening and start again in the morning. Exact times vary by operator and season. Outside these hours, the only way across is by road via the bridges at Mainz/Wiesbaden or Koblenz. This can turn a crossing of a few hundred metres into a detour of many tens of kilometres.
• High and low water. At very high water (flooding), ferry landings can be flooded and services may be suspended. At very low water, operations can also be restricted.
• Weather and ice. Fog, storms and, in rare cold winters, ice can interrupt services.
• Capacity and cost. Ferries carry a limited number of vehicles per trip, charge fares, and cannot easily take very large or heavy vehicles.
• Economic fragility. Ferry businesses depend on fare income. Their finances can be affected by fuel prices, maintenance costs and changes in demand.

These limitations matter for commuters, for businesses, and especially for emergency services. Ambulance and fire services, as well as access to hospitals, have to be planned around the possibility that the river cannot be crossed at a given time. This is one of the main arguments made for a fixed crossing.

History

Before fixed bridges

For most of history, the whole Rhine below Basel was crossed mainly by boats, ferries and temporary structures, not by permanent bridges. The Romans built bridges at a few points. They include the two military bridges Julius Caesar built in the area of the Neuwied Basin in the 50s BC, and a permanent bridge at Mainz. However, these did not survive into the Middle Ages.

From the Middle Ages to the 19th century, river towns typically used:

• Ferries rowed or poled across the river.
• Flying ferries (fliegende Brücken): reaction ferries attached to a long cable anchored upstream. The current pushes them across the river.
• Boat bridges (Schiffbrücken): pontoon bridges made of boats joined together, which could be opened for shipping. Mainz, Koblenz and Cologne all had such crossings at various times.

The middle Rhine gorge was also historically divided between many territories and toll stations. The Pfalzgrafenstein castle on an island near Kaub is a well-known example of a medieval Rhine toll station. The river was a source of income and a political boundary, not something to be crossed easily.

The crossing at Kaub, 1814

The gorge has also been the site of famous military crossings. On the night of 31 December 1813 to 1 January 1814, during the Wars of Liberation against Napoleon, the Prussian field marshal Gebhard Leberecht von Blücher led part of the Allied Silesian Army across the Rhine at Kaub. They used a pontoon bridge, assisted by Russian engineers. A monument to Blücher stands in Kaub.

The age of railway bridges

Fixed bridges spread along the Middle and Lower Rhine from the mid-19th century, driven mainly by the railways. Mainz, Koblenz, Cologne and other cities gained permanent railway and road bridges. However, no fixed bridge was built across the gorge between Bingen and Koblenz in this period. The towns there were small, the valley was narrow, and both banks already had their own railway lines running parallel to the river.

The Hindenburg Bridge (1915–1945)

The only fixed crossing ever built within the present gap was the Hindenburg Bridge (Hindenburgbrücke), a railway bridge between Bingen (Kempten) on the left bank and Rüdesheim on the right bank. It opened in 1915, during the First World War. It was built largely for strategic reasons, to improve rail links towards the Western Front.

In March 1945, near the end of the Second World War, the bridge was destroyed as Allied forces advanced. It was never rebuilt. Remains of its approaches and piers can still be seen near Bingen and Rüdesheim. Since 1945, there has been no fixed crossing anywhere between Mainz/Wiesbaden and Koblenz.

A better-known example of a Rhine bridge that was lost and never replaced is the Ludendorff Bridge at Remagen, further downstream. US forces captured it on 7 March 1945, and it collapsed ten days later. It lies in the second-longest gap in Germany (see below).

Why the gap has persisted

Several reasons are usually given for why no bridge has been built in the gorge since 1945:

1. Topography. In the gorge, the valley floor is narrow. Steep, often terraced slopes rise directly from the river. A railway line and a federal road already occupy each bank. A bridge needs approach roads that climb out of the valley or connect to the bank roads without blocking the railways. This is technically difficult and expensive.
2. Shipping. The Rhine in the gorge is a busy and, in places, difficult waterway. Notable hazards include the Binger Loch near Bingen and the bends near the Loreley. A bridge must leave sufficient clearance and width for shipping. Piers in the river can create additional hazards.
3. Population and traffic demand. The communities in the gorge are small, and many have been losing population for decades. The traffic case for a large bridge is therefore weaker than near big cities. Supporters argue that the lack of a bridge has itself contributed to this decline.
4. Landscape and heritage. The gorge is famous for its scenery and has been a symbol of Romanticism since the late 18th and early 19th centuries. Since 2002, it has also been a World Heritage Site. Any large structure has to be considered for its visual effect on the protected landscape.
5. Funding and responsibility. It has long been disputed which level of government should plan and pay for a bridge, and what category of road it would carry. The options discussed have included a district road, a state road and federal funding.
6. Changing political majorities. The governing coalitions in Rhineland-Palatinate have taken different positions on the project over time (see below).

The Mittelrheinbrücke debate

Location

The proposed Mittelrheinbrücke is a road bridge in the central part of the gorge. Its preferred location is between Fellen, part of St. Goar on the left bank, and Wellmich, part of St. Goarshausen on the right bank. This is a short distance downstream of the Loreley. A crossing here would roughly halve the gap and would connect the Hunsrück side with the Taunus side in the middle of the valley.

The Dresden precedent

An important background to the debate is the case of Dresden. The Dresden Elbe Valley was inscribed as a World Heritage Site in 2004. After the city went ahead with a four-lane road bridge, the Waldschlösschenbrücke, UNESCO removed the site from the World Heritage List in 2009. This was one of only a few such deletions. It showed that a bridge could cost a region its World Heritage status. Opponents and cautious politicians in Rhineland-Palatinate referred to this case repeatedly.

Political history

The following summary covers the main phases. Exact dates of individual decisions and procedures are not all given here, because published accounts differ in detail.

• Long-standing local demand. Calls for a bridge in the gorge go back many decades. They come especially from local councils, businesses and residents in the Rhein-Hunsrück and Rhein-Lahn districts.
• Planning and UNESCO concerns (2000s). After the World Heritage inscription in 2002, plans for a bridge were developed further. They were accompanied by studies of how a bridge might affect the protected landscape. UNESCO and its advisory body ICOMOS (the International Council on Monuments and Sites) took an interest in the project.
• Halt under the SPD–Green coalition (2011–2016). After the 2011 state election, the SPD and the Greens formed a coalition government in Rhineland-Palatinate. They agreed not to pursue the bridge during that legislative period. The Greens in particular opposed it.
• Revival (from 2016). After the 2016 state election, the new coalition of SPD, FDP and Greens agreed to resume planning. The CDU opposition and the FDP had long supported the bridge.
• Regional planning procedure. A Raumordnungsverfahren was carried out. This is a German regional planning procedure that checks whether a major project fits with land-use and regional plans, and compares possible locations. It confirmed the general feasibility of a bridge at the Fellen–Wellmich location.
• Funding question. For some time, the bridge was planned as a district road project, with the districts as project owners and state subsidies. This raised concerns about the financial burden on the districts. Later, the state government moved towards treating it as a state road project. This would place planning and construction under the state road authority, the Landesbetrieb Mobilität.

As of the mid-2020s, detailed planning was continuing, but construction had not started. Any bridge would still need full planning approval (Planfeststellung), and it could face legal challenges. Opening is not expected in the near term.

Arguments for the bridge

• It would provide a crossing at all hours, independent of ferry timetables, weather and water levels.
• It would improve access to jobs, schools, hospitals and shops on the opposite bank.
• It would make emergency services more reliable.
• Supporters hope it would slow population decline and support tourism and the local economy in a structurally weak region.
• Supporters argue that a carefully designed, low-impact bridge can be compatible with World Heritage status. UNESCO bodies have indicated in principle that this could be possible, provided the design is suitable.

Arguments against the bridge, or for caution

• It could cause visual harm to a protected cultural landscape and carries a risk to World Heritage status.
• Costs are high compared with the size of the local population. Cost estimates have risen over time.
• It could draw additional through traffic, including heavy goods vehicles, onto narrow valley and hillside roads.
• It could harm the existing ferries. Losing their income could leave other parts of the gorge worse served.
• Some people argue that improved ferries, including longer operating hours or night services, could meet much of the need at lower cost.

Alternatives discussed

Alternatives and complements to a bridge have been discussed. They include subsidised night ferry services, better coordination of ferry timetables, and modernised vessels. Some of these measures have been tried or proposed. Their supporters see them either as a bridge substitute or as a necessary interim solution until a bridge exists.

Other unbridged stretches

Neuwied to Bonn

The second notable gap on the German Rhine lies downstream of Koblenz. Around Koblenz and Neuwied, there are several bridges, including the motorway bridge of the A48 at Bendorf, a railway bridge at Urmitz, and the Raiffeisen Bridge at Neuwied. After Neuwied, the next fixed crossing is in the south of Bonn. The gap is roughly 40 kilometres long.

This stretch includes Andernach, Bad Breisig, Bad Hönningen, Linz am Rhein, Remagen, Unkel, Bad Honnef and Königswinter. Here too, crossings depend on ferries, such as Bad Breisig – Bad Hönningen, Linz – Kripp (Remagen) and Königswinter – Bad Godesberg (Mehlem). The remains of the Ludendorff Bridge at Remagen and Erpel lie in this section. Its towers now house a peace museum on the Remagen side.

The Lower Rhine

On the Lower Rhine, between the Ruhr area and the Dutch border, bridges are generally spaced further apart than in the big cities upstream. Ferries such as Walsum – Orsoy and Xanten – Bislich serve some of the gaps. The German Lower Rhine has notable bridges at Wesel, Rees and Emmerich. The Emmerich Rhine Bridge, opened in 1965, is one of the longest suspension bridges in Germany. None of the gaps on the Lower Rhine is as long as the Mainz–Koblenz gap.

The Upper Rhine

Between Basel and Karlsruhe, the Rhine forms the border between France and Germany. Many crossings are provided by bridges and by roads over the dams and locks of the hydroelectric plants built on the river and the Grand Canal d'Alsace in the 20th century. A few ferries also operate. Examples include the Kappel – Rhinau ferry and the Seltz – Plittersdorf ferry. Distances between fixed crossings on this section are generally modest.

Lake Constance

Lake Constance (Bodensee) is formally part of the course of the Rhine. The river enters the lake near Bregenz and leaves it at Konstanz. The main body of the lake, the Obersee, is about 60 kilometres long and has no bridge across it. Crossings are made by ferry, for example Konstanz – Meersburg and Friedrichshafen – Romanshorn. Lakes are normally treated separately from the river itself, so Lake Constance is usually not counted when people discuss unbridged stretches of the Rhine.

The Netherlands

In the Netherlands, the Rhine divides into several branches. The main ones are the Waal, the Nederrijn–Lek and the IJssel. These branches are crossed by many bridges, but the country also has a long tradition of small river ferries. Some ferries serve stretches where the nearest bridge is some distance away. Because the river is split into several channels, it is not usual to speak of a single "longest unbridged stretch" in the Dutch delta.

Cultural and tourism aspects

The lack of bridges is part of the character of the Upper Middle Rhine Valley. Ferry crossings, castle views and river cruises are central to the tourist experience. The ferries themselves are sometimes promoted as attractions.

Many visitors explore the valley by combining boat trips with trains on both banks and ferries between them. Long-distance walking trails run along both sides of the gorge: the Rheinsteig on the right bank and the RheinBurgenWeg on the left bank. Hikers often use the ferries to switch between the trails.

The Upper Middle Rhine Valley has been chosen to host the Federal Garden Show (Bundesgartenschau, BUGA) in 2029. Transport links within the valley, including crossings of the river, have featured in planning discussions around this event.

Open questions

• Whether, when and in what form the Mittelrheinbrücke will be built. Open issues include legal approval, final cost and funding arrangements.
• How UNESCO will assess the final design, and whether the World Heritage status of the Upper Middle Rhine Valley will be affected.
• How the remaining ferries will be financed and whether night-time services can be secured, with or without a bridge.
• Whether a bridge would reverse, slow or have little effect on population decline in the gorge communities.

See also

• Rhine
• Upper Middle Rhine Valley
• Rheingau
• Loreley
• Mittelrheinbrücke
• Hindenburg Bridge (Bingen)
• Ludendorff Bridge (Remagen)
• List of crossings of the Rhine
• Rhine kilometre
• Rhine ferries
• Dresden Elbe Valley
• West Rhine Railway and East Rhine Railway
• Rheinsteig
• Central Commission for the Navigation of the Rhine