All megacities have one thing in common: challenges posed by the transport of people and goods. Unlike most cities that “just” struggle with noise, city smog, energy use, emissions of greenhouse gases and the cost for the transports, megacities face severe shortage of road and other infrastructure for transports.
Mostly the street space is consumed first for cars and buses, and rail is built for tram and trains. Next, underground rail is built for metro lines and in some cities elevated rail or skyways are used. Criticism is pointed towards the unattractive environment for the travelers in underground “piping”. And, for public transports above the ground citizens living close to the major transport channels are disturbed.
Megacities constantly run into capacity problems for their transports. Eduardo Paes (mayor of Rio de Janeiro) describes the dilemma in “The four Commandments of Cities” on TED talk from 2012.
I learned from another Latin American mayor recently that one of the main priorities is to plan the city for a minimum of transports. Cities that rely on lots of traveling for many people sooner get into congestion issues than cities that are structured to minimize the need for travel. In Hong Kong for example most people walk to work. The city allows people to live close to offices. In other cities, where shopping centra, business districts, residential areas and industrial parks are well separated by considerable distances, public and private transports are required.
However, even when care is taken to minimize the need for transport, a lot of travelling will be required. For those cities the efficient use of the street space is of high importance.
Common structures to cope with high capacity travel are:
1) Grids of mega corridors of roads or rails
2) Multiple ring roads/metro
3) Integrated roads for car, bus, bike and walking*
4) Local availability (in each city district as well as in each suburb) of fundamental functions of society, such as shops, banks, drug stores, etc.
* For example as described here by Tender S.U.R.E.
For all public transports some common factors are crucial for efficient transports in megacities.
In fact, many less developed cities in the industrialized world still struggle with basic priority issues, in contrary to rapidly developing cities utilizing modern knowledge on transports of people and gods.
Bus Rapid Transit (BRT) systems are used in several megacities. Some of the basics include:
1) High average speed is a necessity for high transport capacity
2) Rapid boarding is required
3) The driver should focus on driving alone, ticketing and similar should be done in other ways
4) Direct door-to-door travel minimize capacity issues for major transport centra
5) High frequency of the service attract more passengers
6) Routs with higher capacity requirement shall have priority over transports with lower capacity
In the end the capacity of different public transports is a subject of political decisions, alone.