Traffic Congestion (DP IB Geography): Revision Note

Traffic Congestion Patterns & Trends

• Many urban areas grow faster than the local government can improve and extend the area's infrastructure

• This leads to challenges such as traffic congestion

What is traffic congestion?

• Traffic congestion is when:

  • Traffic flow is significantly reduced

  • There is a reduction in vehicle speed

  • The number of vehicles is increased

• The view of what constitutes traffic congestion varies from place to place

• Traffic congestion affects both people and the environment

• The extent of traffic congestion depends on several factors, including:

  • Size of the urban area

  • Urban planning

  • Population density

  • Transport infrastructure

  • Population density

• These factors affect the amount of traffic and its flow through the urban area

Patterns of traffic congestion

Peak hour congestion

• Cities all experience peak-hour congestion

• This is increased traffic during morning and evening rush hours

• It occurs when most people are travelling to and from work

Events 

• Urban areas often experience traffic surges when there are events such as concerts or sporting competitions 

• The amount of traffic is unpredictable and can cause significant congestion

Seasonal variation

• The patterns of traffic change during public holidays, school holidays or seasonal events

• This can lead to both increases and decreases in traffic

Bottlenecks

• These are locations in urban areas where congestion regularly occurs, such as at particular junctions in the traffic infrastructure

Trends of traffic congestion

Urban expansion

• As cities expand, they will experience all of the following, which will increase the amount of traffic on the roads:

  • Growth of industries and businesses

  • Population increase

  • Increased size of the urban area 

Increased wealth

• Increased wealth means that more people can afford cars

• Fewer people are using public transport

Traffic Congestion Impacts

• There are several impacts of traffic congestion including:

  • Increased pollution

  • Longer journey times

  • Unpredictable journey times

  • Slower speeds

  • Increased stopping and starting

Increased pollution

• More traffic and starting and stopping leads to higher emissions in urban areas

• Congestion in London is estimated to increase emissions by 15%, in Berlin it is estimated to be an 11% increase in emissions

  • Imperial College London's research estimates that pollution caused the premature deaths of 4000 London residents in 2019

• In Delhi, India, 67% of pollution is from traffic and it is estimated to lead to 5000 premature deaths a year

Longer and more unpredictable journey times

• The slower traffic impacts the economy

  • In London it is estimated that traffic congestion costs the economy £5.1bn a year

• Research shows that in 2021, the average driver in London spent 148 hours sitting in traffic

Case Study: Rio de Janeiro

• Rio de Janeiro has a population of 6.7 million (2020)

• The population of the greater metropolitan area is estimated at 13.5 million

• The mountainous landscape surrounding the city increases the issues with traffic because:

  • A large volume of traffic is forced into only a few roads

• Air pollution causes approximately 5000 premature deaths a year

Causes of traffic congestion in Rio de Janeiro

• Car ownership in Brazil has increased by over 25% between 2012 and 2022

• The average journey during rush hour takes 50% longer than at other times

• Buses are the main form of transport but there are a number of issues with the bus system, including:

  • There are too few buses for the number of passengers

  • Safety fears, particularly at night

  • Lack of air conditioning 

• Bottlenecks, such as the ones at either end of the Rio Niteroi Bridge, are common

  • The bridge is 14km long and saves an 80km journey 

  • Cars often breakdown on the bridge, leading to longer journey times

Traffic management in Rio de Janeiro

• There have been several attempts to manage traffic congestion in Rio de Janeiro including:

  • Yellow Line Expressway

  • Rio Niteroi Bridge

  • Metro Rio

  • Trams

  • Bike Rio

• All the management schemes aim to reduce the amount of traffic on the roads

• The schemes include both public and private strategies

Yellow Line Expressway

• The expressway connects Barra da Tijuca to the North Zone and the international airport

• The cost of the road building was so high that it is now a toll road

• Every day, 70 000 vehicles use it

  • This is 13 000 more than it was built for, which has led to congestion

• It has reduced traffic on local roads by 40%

Rio Niteroi Bridge

• The bridge was built to replace a one-hour ferry crossing or an 80 km road journey

• Although effective in reducing journey time, it experiences bottlenecks and congestion due to its popularity

Metro Rio

• Three subway lines cross Rio de Janeiro

• There are 41 subway stations

• The metro carries over 1 million passengers a day

Trams

• A tram system connecting the port to the city centre and the airport

• There are no emissions 

• There are 300 000 users per day

• The trams decrease journey times 

Bike Rio

• Bike Rio began in 2011

• It is a bicycle-sharing scheme

  • There are 600 bicycles available at 60 rental stations across Rio de Janeiro

  • The cycle lanes cross 450 km

  • Solar panels power the bike stations