Traffic Congestion (SL IB Geography)

• 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

• 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

• 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