Paris is the second-most densely populated city in Europe, with 52,218 people per square kilometre. People walk, bike, skate, drive and commute on public transport. Many Parisian roads are one-way streets, and these narrow ways are shared by cars, buses, motorbikes and other micro-mobility devices. What daily obstacles do people face trying to get to work, running errands, or meeting friends and family? Are there contingency plans when parts of the system are blocked or under maintenance?


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There is no question that Paris has a reputation for beauty, culture and history. However, the inherent design of the city, together with its narrow passageways, means that roads are often maze-like, and getting from point A to point B may require complex manoeuvring, particularly for larger vehicles and buses. Let’s zoom in on the challenges for public transport authorities in minimising disruptions to passengers’ daily lives. 


Challenges faced by public transport authorities in Paris

Public transport authorities” in Paris means mainly the Régie Autonome des Transports Parisiens (RATP), the body responsible for metros, buses, tramways, and for part of the RER lines A and B. The Société Nationale des Chemins de Fer, the French national railway company, operates all of the lines C, D, and E and part of lines A and B of the RER. 

Transport authorities recognise “disturbances” and “disruptions.” Both are deviations from the operations plan, yet they are different: disturbances refer to recurrent conditions and to minor quasi-continuous events, while disruptions refer to non-recurrent conditions and major events.

Taken from IVT, ETH Zurich


Since the metro system of Paris shares tracks with at least one other line at some point, disruptions can have significant network-wide effects. And buses often encounter roadworks. Micro-mobility devices became more popular during the pandemic, since they reduce the need to crowd in buses and metro trains, but their proliferation on the streets poses a different problem. 

With the cycle paths doubling between July 2019 and 2020, the challenge will be to make Parisian bus traffic more fluid while offering a range of cycle paths adapted to the increase in the number of bicycles. This is especially pertinent since the additional 50 kilometres of traffic lanes used by cars became cycling paths (coronapistes).

Contingency plans in the event of disruptions

Photo by Dmitriy Nushtaev on Unsplash

Disruption management is “an ongoing process rather than a single problem that can be formulated explicitly.” When an unplanned event occurs, dispatchers may notice it on their monitoring screens or they may be notified by a driver, for instance. Then they must decide whether or to act immediately or not. In Paris, passengers  who encounter unplanned obstacles on the street, such as a fire engine or other vehicle obstructing traffic, are refunded if they prefer not to wait while the bus driver contacts the command centre and awaits instructions. There are also shuttle buses provided in the event that important metro or RER lines are disrupted for maintenance work. 

Possible solutions to public transport stresses


Photo by Hal Gatewood on Unsplash

Bridging buses called in to replace the rail service on the disrupted lines may take long to arrive, and are costly to keep stand-by. Another problem of the bus bridging approach is that the extra buses and drivers must either be kept on stand-by or moved from their original lines. 

Demand-responsive transport such as taxis can react to demand almost immediately, but is costly and must usually be arranged by individual travellers.  A 2021 study argues that operating both bridging buses and demand-responsive transport in coordination can provide the best tradeoff between cost and waiting time. A small number of demand-responsive vehicles and a limited number of buses can provide a sufficient level of service for disruption management at low cost. Hence, an integrated ride-sharing and public transport system to achieve reliable and efficient transfers between the two forms of services.

A tool using Variable Message Signs acting as an Advanced Traveller Information System can mitigate disruptions and improve traffic flow in the road networks. The information helps passengers decide whether to wait for service to resume and, if not, which detour to choose. Applications such as Citymapper also help passengers factor in disruptions (whether planned or unplanned) in deciding their transport routes.

Living with disrupted public transport

In March 2020, the disruptions caused by the onset of the Covid-19 pandemic were minimised by RATP, at a time when other public transport systems in Europe shut down and made alternative arrangements. The number of innovations that communicate disruptions to passengers has increased, thereby reducing waiting time for passengers. While disruptions remain unavoidable, the management systems and other tools to compensate for delayed travel times continue to evolve.