Public transport is an essential service for major cities, allowing people to travel effortlessly and speedily to their destinations.
Taking the bus or metro has many positive benefits, such as helping to reduce emissions and ease congestion on the roads.
Public transport is also cheaper than owning and operating a car, particularly as fuel prices have risen sharply in recent years.
But to encourage people to keep using public transport, governments and city councils need to continually invest in transport infrastructure.
One European capital is doing just that as it launches an ambitious project to upgrade and expand its public transport networks.
Paris is embarking on a £30 billion plan to build new rapid transit lines and to extend existing ones.
Known as the Grand Paris Express, the metro will have four new lines and extensions to Lines 11 and 14.
This mega project will see 120 miles of new track laid and 68 new stations added, serving an estimated three million passengers a day.
One of its major advantages is that it will allow people to travel quickly from suburb to suburb without going through Paris.
Eighty percent of the new stations will be connected to the existing metro, RER, Transilien and tramway network.
Thanks to its design and the distances between stations, the trains will run at an average speed of between 55 and 65 km/h, with a maximum speed of 110 km/h.
For comparison, the Paris metro currently runs at an average speed of between 21 and 27 km/h.
The building of the new metro lines is running in tandem with other urban projects currently under construction, as is the case on the Saclay plateau.
It is also the fulcrum of many real estate projects in Île-de-France that will improve the quality of life of residents.
The Société des Grands Projets is participating in this process. The land acquired for the construction of the metro will be used for more than 100 real estate projects.
The constructed lines will open in stages, starting with the Line 14 extension in June 2024 until 2030.